Why was North and South America less developed than other parts of the world? [duplicate]

Why was North and South America less developed than other parts of the world? [duplicate]

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Let me preface this with stating that the pre-columbian period of mesoamerica and the Andes Mountain regions are my favorite areas of study and I am fully aware of the advanced civilizations that spawned there: The Incans, Mayans, Olmec, Toltec, Aztec, Zapotec, Mixtec, etc. to name a few. But, if you look at the largest and most influential civilizations in the world, they are mainly contained to the Eurasian continent. To name a few: Romans, Greeks, Phoenicians, Chinese, Mongolians, Persians, Siam, Portuguese, Spanish, French, English, Ottomans, etc. The Phoenicians did not cover much land, but they were arguably the best seafaring society of their day. Their civilization was partly the basis of the Greeks which did have a very successful empire. The mongols had the biggest empire ever (maybe the British were bigger, but I feel the mongols were much more impressive given the time). The Chinese have historically been the most powerful civilization ever (except for the last ~two centuries).

Do not get me wrong, the Aztec and Incans were amazing civilizations and my two favorite ones to study, but they never covered the same area and had as much influence as civilizations in Eurasia and northern Africa. The Aztecs only took over central mexico. The Inca actually were a decent size, but that is really the only one out of all the Americas.

I think that the Gulf of Mexico and Caribbean Sea offer a similar seafaring potential that the Mediterranean offered. I would have expected one or two civilizations to really take advantage of the water and really take over this area like the Romans did in Europe. I just think there are several areas in the Americas that geographically would be ripe for lots of trade and conquest like we saw in Eurasia.

From the context of your question I take it that when you say "Developed" you don't mean technologically developed but rather that said civilization "obtained a geographically large empire."

So to answer the question why didn't pre-columbian Americas have as many large empires,

A) The historic records for pre-columbain Americas is almost non-existent compared to the old world. So in fact there may (and in my opinion likely were) just as many large empires, we just don't have any records of them.

B) A lack of faster and easier than walking travel would have limited troop movement, supply lines and exploration. All of which are important for the growth of an empire.

C) Empires by very definition exist to capture new wealth and bring it back to the capital. It could have simply been that any Nations that did arise simply didn't see any opportunities to conquer that wealth. For example the Incas did not value gold and silver as much as they did fine cloth. source wikipedia If you don't see anything nearby that you think is worth conquering then why make the effort.


Isolation of South America Edit

After the late Mesozoic breakup of Gondwana, South America spent most of the Cenozoic era as an island continent whose "splendid isolation" allowed its fauna to evolve into many forms found nowhere else on Earth, most of which are now extinct. [8] Its endemic mammals initially consisted primarily of metatherians (marsupials and sparassodonts), xenarthrans, and a diverse group of native ungulates known as the Meridiungulata: notoungulates (the "southern ungulates"), litopterns, astrapotheres, pyrotheres and xenungulates. [n 1] [n 2] A few non-therian mammals – monotremes, gondwanatheres, dryolestids and possibly cimolodont multituberculates – were also present in the Paleocene while none of these diversified significantly and most lineages did not survive long, forms like Necrolestes and Patagonia remained as recently as the Miocene. [15]

Marsupials appear to have traveled via Gondwanan land connections from South America through Antarctica to Australia in the late Cretaceous or early Tertiary. [16] [n 3] One living South American marsupial, the monito del monte, has been shown to be more closely related to Australian marsupials than to other South American marsupials (Ameridelphia) however, it is the most basal australidelphian, [n 4] meaning that this superorder arose in South America and then dispersed to Australia after the monito del monte split off. [16] Monotrematum, a 61-Ma-old platypus-like monotreme fossil from Patagonia, may represent an Australian immigrant. [17] [18] Paleognath birds (ratites and South American tinamous) may have made a similar migration around the same time to Australia and New Zealand. [19] [20] Other taxa that may have dispersed by the same route (if not by flying or oceanic dispersal) are parrots, chelid turtles, and the extinct meiolaniid turtles.

Marsupials remaining in South America included didelphimorphs (opossums), paucituberculatans (shrew opossums) and microbiotheres (monitos del monte). Larger predatory relatives of these also existed, such as the borhyaenids and the saber-toothed Thylacosmilus these were sparassodont metatherians, which are no longer considered to be true marsupials. [21] As the large carnivorous metatherians declined, and before the arrival of most types of carnivorans, predatory opossums such as Thylophorops temporarily attained larger size (about 7 kg).

Metatherians and a few xenarthran armadillos, such as Macroeuphractus, were the only South American mammals to specialize as carnivores their relative inefficiency created openings for nonmammalian predators to play more prominent roles than usual (similar to the situation in Australia). Sparassodonts and giant opossums shared the ecological niches for large predators with fearsome flightless "terror birds" (phorusrhacids), whose closest living relatives are the seriemas. [22] [23] North America also had large terrestrial predatory birds during the early Cenozoic (the related bathornithids), but they died out before the GABI in the Early Miocene, about 20 million years ago. Through the skies over late Miocene South America (6 Ma ago) soared one of the largest flying birds known, Argentavis, a teratorn that had a wing span of 6 m or more, and which may have subsisted in part on the leftovers of Thylacosmilus kills. [24] Terrestrial sebecid (metasuchian) crocodyliforms with ziphodont teeth [n 5] were also present at least through the middle Miocene [25] [26] [27] [28] and maybe to the Miocene-Pliocene boundary. [29] Some of South America's aquatic crocodilians, such as Gryposuchus, Mourasuchus and Purussaurus, reached monstrous sizes, with lengths up to 12 m (comparable to the largest Mesozoic crocodyliforms). They shared their habitat with one of the largest turtles of all time, the 3.3 m (11 ft) Stupendemys.

Xenarthrans are a curious group of mammals that developed morphological adaptations for specialized diets very early in their history. [30] In addition to those extant today (armadillos, anteaters, and tree sloths), a great diversity of larger types was present, including pampatheres, the ankylosaur-like glyptodonts, predatory euphractines, various ground sloths, some of which reached the size of elephants (e.g. Megatherium), and even semiaquatic to aquatic marine sloths. [31] [32]

The notoungulates and litopterns had many strange forms, such as Macrauchenia, a camel-like litoptern with a small proboscis. They also produced a number of familiar-looking body types that represent examples of parallel or convergent evolution: one-toed Thoatherium had legs like those of a horse, Pachyrukhos resembled a rabbit, Homalodotherium was a semibipedal, clawed browser like a chalicothere, and horned Trigodon looked like a rhinoceros. Both groups started evolving in the Lower Paleocene, possibly from condylarth stock, diversified, dwindled before the great interchange, and went extinct at the end of the Pleistocene. The pyrotheres and astrapotheres were also strange, but were less diverse and disappeared earlier, well before the interchange.

The North American fauna was a typical boreoeutherian one, supplemented with Afrotherian proboscids.

Pre-GABI oceanic dispersals Edit

The invasions of South America started about 40 Ma ago (middle Eocene), when caviomorph rodents arrived in South America. [33] [34] [35] Their subsequent vigorous diversification displaced some of South America's small marsupials and gave rise to – among others – capybaras, chinchillas, viscachas, and New World porcupines. The independent development of spines by New and Old World porcupines is another example of parallel evolution. This invasion most likely came from Africa. [36] [37] The crossing from West Africa to the northeast corner of Brazil was much shorter then, due to continental drift, and may have been aided by island hopping (e.g. via St. Paul's Rocks, if they were an inhabitable island at the time) and westward oceanic currents. [38] Crossings of the ocean were accomplished when at least one fertilised female (more commonly a group of animals) accidentally floated over on driftwood or mangrove rafts. Hutias (Capromyidae) would subsequently colonize the West Indies as far as the Bahamas, [39] [40] reaching the Greater Antilles by the early Oligocene. [41] Over time, some caviomorph rodents evolved into larger forms that competed with some of the native South American ungulates, which may have contributed to the gradual loss of diversity suffered by the latter after the early Oligocene. [8] By the Pliocene, some caviomorphs (e.g., Josephoartigasia monesi) attained sizes on the order of 500 kg (1,100 lb) or larger. [42]

Later (by 36 Ma ago), [43] primates followed, again from Africa in a fashion similar to that of the rodents. [33] Primates capable of migrating had to be small. Like caviomorph rodents, South American monkeys are believed to be a clade (i.e., monophyletic). However, although they would have had little effective competition, all extant New World monkeys appear to derive from a radiation that occurred long afterwards, in the Early Miocene about 18 Ma ago. [33] Subsequent to this, monkeys apparently most closely related to titis island-hopped to Cuba, Hispaniola, and Jamaica. Additionally, a find of seven 21-Ma-old apparent cebid teeth in Panama suggests that South American monkeys had dispersed across the seaway separating Central and South America by that early date. However, all extant Central American monkeys are believed to be descended from much later migrants, and there is as yet no evidence that these early Central American cebids established an extensive or long-lasting population, perhaps due to a shortage of suitable rainforest habitat at the time. [44] [45]

Fossil evidence presented in 2020 indicates a second lineage of African monkeys also rafted to and at least briefly colonized South America. Ucayalipithecus remains dating from the Early Oligocene of Amazonian Peru are, by morphological analysis, deeply nested within the family Parapithecidae of the Afro-Arabian radiation of parapithecoid simians, with dental features markedly different from those of platyrrhines. The Old World members of this group are thought to have become extinct by the Late Oligocene. Qatrania wingi of lower Oligocene Fayum deposits is considered the closest known relative of Ucayalipithecus. [46] [47]

Remarkably, the descendants of those few bedraggled "waifs" that crawled ashore from their rafts of African flotsam in the Eocene now constitute more than twice as many of South America's species as the descendants of all the flightless mammals previously resident on the continent (372 caviomorph and monkey species versus 136 marsupial and xenarthran species). [n 6]

Many of South America's bats may have arrived from Africa during roughly the same period, possibly with the aid of intervening islands, although by flying rather than floating. Noctilionoid bats ancestral to those in the neotropical families Furipteridae, Mormoopidae, Noctilionidae, Phyllostomidae, and Thyropteridae are thought to have reached South America from Africa in the Eocene, [49] possibly via Antarctica. [50] Similarly, free-tailed bats (Molossidae) may have reached South America from Africa in as many as five dispersals, starting in the Eocene. [49] Emballonurids may have also reached South America from Africa about 30 Ma ago, based on molecular evidence. [49] [51] Vespertilionids may have arrived in five dispersals from North America and one from Africa. [49] Natalids are thought to have arrived during the Pliocene from North America via the Caribbean. [49]

Tortoises also arrived in South America in the Oligocene. They were long thought to have come from North America, but a recent comparative genetic analysis concludes that the South American genus Chelonoidis (formerly part of Geochelone) is actually most closely related to African hingeback tortoises. [n 7] [52] Tortoises are aided in oceanic dispersal by their ability to float with their heads up, and to survive up to six months without food or water. [52] South American tortoises then went on to colonize the West Indies [53] and Galápagos Islands (the Galápagos tortoise). A number of clades of American geckos seem to have rafted over from Africa during both the Paleogene and Neogene. [54] Skinks of the related genera Mabuya and Trachylepis apparently dispersed across the Atlantic from Africa to South America and Fernando de Noronha, respectively, during the last 9 Ma. [55] Surprisingly, South America's burrowing amphisbaenians [56] and blind snakes [57] also appear to have rafted from Africa, as does the hoatzin, a weak-flying bird of South American rainforests. [58]

The earliest traditionally recognized mammalian arrival from North America was a procyonid that island-hopped from Central America before the Isthmus of Panama land bridge formed, around 7.3 Ma ago. [59] This was South America's first eutherian carnivore. South American procyonids then diversified into forms now extinct (e.g. the "dog-coati" Cyonasua, which evolved into the bear-like Chapalmalania). However, all extant procyonid genera appear to have originated in North America. [60] The first South American procyonids may have contributed to the extinction of sebecid crocodilians by eating their eggs, but this view has not been universally viewed as plausible. [n 8] [28] The procyonids were followed to South America by rafting or island-hopping hog-nosed skunks [61] and sigmodontine rodents. [62] [63] [64] [65] The oryzomyine tribe of sigmodontine rodents went on to colonize the Lesser Antilles to Anguilla.

One group has proposed that a number of large Neartic herbivores actually reached South America as early as 9–10 Ma ago, in the late Miocene, via an early incomplete land bridge. These claims, based on fossils recovered from rivers in southwestern Peru, have been viewed with caution by other investigators, due to the lack of corroborating finds from other sites and the fact that almost all of the specimens in question have been collected as float in rivers without little to no stratigraphic control. [66] These taxa are a gomphothere (Amahuacatherium), [67] [68] peccaries (Sylvochoerus and Waldochoerus), [69] tapirs and Surameryx, a palaeomerycid (from a family probably ancestral to cervids). [70] The identification of Amahuacatherium and the dating of its site is controversial it is regarded by a number of investigators as a misinterpreted fossil of a different gomphothere, Notiomastodon, and biostratigraphy dates the site to the Pleistocene. [71] [72] [73] The early date proposed for Surameryx has also been met with skepticism. [74]

Megalonychid and mylodontid ground sloths island-hopped to North America by 9 Ma ago. [62] A basal group of sloths [75] had colonized the Antilles previously, by the early Miocene. [76] In contrast, megatheriid and nothrotheriid ground sloths did not migrate north until the formation of the isthmus. Terror birds may have also island-hopped to North America as early as 5 Ma ago. [77]

The Caribbean Islands were populated primarily by species from South America, due to the prevailing direction of oceanic currents, rather than to a competition between North and South American forms. [39] [40] Except in the case of Jamaica, oryzomyine rodents of North American origin were able to enter the region only after invading South America.

The formation of the Isthmus of Panama led to the last and most conspicuous wave, the Great American Biotic Interchange (GABI), starting around 2.7 Ma ago. This included the immigration into South America of North American ungulates (including camelids, tapirs, deer and horses), proboscids (gomphotheres), carnivorans (including felids such as cougars and saber-toothed cats, canids, mustelids, procyonids and bears) and a number of types of rodents. [n 9] The larger members of the reverse migration, besides ground sloths and terror birds, were glyptodonts, pampatheres, capybaras, and the notoungulate Mixotoxodon (the only South American ungulate known to have invaded Central America).

In general, the initial net migration was symmetrical. Later on, however, the Neotropic species proved far less successful than the Nearctic. This difference in fortunes was manifested in several ways. Northwardly migrating animals often were not able to compete for resources as well as the North American species already occupying the same ecological niches those that did become established were not able to diversify much, and in some cases did not survive for long. [78] Southwardly migrating Nearctic species established themselves in larger numbers and diversified considerably more, [78] and are thought to have caused the extinction of a large proportion of the South American fauna. [61] [79] [80] (No extinctions in North America are plainly linked to South American immigrants. [n 10] ) Native South American ungulates did poorly, with only a handful of genera withstanding the northern onslaught. (Several of the largest forms, macraucheniids and toxodontids, have long been recognized to have survived to the end of the Pleistocene. Recent fossil finds indicate that one species of the horse-like proterotheriid litopterns did, as well. [82] The notoungulate mesotheriids and hegetotheriids also managed to hold on at least part way through the Pleistocene.) [A] South America's small marsupials, though, survived in large numbers, while the primitive-looking xenarthrans proved to be surprisingly competitive and became the most successful invaders of North America. The African immigrants, the caviomorph rodents and platyrrhine monkeys, were less impacted by the interchange than most of South America's 'old-timers', although the caviomorphs suffered a significant loss of diversity, [n 11] [n 12] including the elimination of the largest forms (e.g. the dinomyids). With the exception of the North American porcupine and several extinct porcupines and capybaras, however, they did not migrate past Central America. [n 13]

Due in large part to the continued success of the xenarthrans, one area of South American ecospace the Nearctic invaders were unable to dominate was the niches for megaherbivores. [84] Before 12,000 years ago, South America was home to about 25 species of herbivores weighing more than 1000 kg, consisting of Neotropic ground sloths, glyptodonts, and toxodontids, as well as gomphotheres and camelids of Nearctic origin. [n 14] Native South American forms made up about 75% of these species. However, none of these megaherbivores has survived.

Armadillos, opossums and porcupines are present in North America today because of the Great American Interchange. Opossums and porcupines were among the most successful northward migrants, reaching as far as Canada and Alaska, respectively. Most major groups of xenarthrans were present in North America until the end-Pleistocene Quaternary extinction event (as a result of at least eight successful invasions of temperate North America, and at least six more invasions of Central America only). Among the megafauna, ground sloths were notably successful emigrants four different lineages invaded North America. A megalonychid representative, Megalonyx, spread as far north as the Yukon [86] and Alaska, [87] and might well have invaded Eurasia had a suitable habitat corridor across Beringia been present.

Generally speaking, however, the dispersal and subsequent explosive adaptive radiation of sigmodontine rodents throughout South America (leading to over 80 currently recognized genera) was vastly more successful (both spatially and by number of species) than any northward migration of South American mammals. Other examples of North American mammal groups that diversified conspicuously in South America include canids and cervids, both of which currently have three or four genera in North America, two or three in Central America, and six in South America. [n 15] [n 16] Although members of Canis (specifically, coyotes) currently range only as far south as Panama, [n 17] South America still has more extant genera of canids than any other continent. [n 15]

The effect of formation of the isthmus on the marine biota of the area was the inverse of its effect on terrestrial organisms, a development that has been termed the "Great American Schism". The connection between the east Pacific Ocean and the Caribbean (the Central American Seaway) was severed, setting now-separated populations on divergent evolutionary paths. [91] Caribbean species also had to adapt to an environment of lower productivity after the inflow of nutrient-rich water of deep Pacific origin was blocked. [92] The Pacific coast of South America cooled as the input of warm water from the Caribbean was cut off. This trend is thought to have caused the extinction of the marine sloths of the area. [93]

Disappearance of native South American predators Edit

During the last 7 Ma, South America's terrestrial predator guild has changed from one composed almost entirely of nonplacental mammals (metatherians), birds, and reptiles to one dominated by immigrant placental carnivorans (with a few small marsupial and avian predators like didelphine opossums and seriemas). It was originally thought that the native South American predator guild, including sparassodonts, carnivorous opossums like Thylophorops and Hyperdidelphys, armadillos such as Macroeuphractus, terror birds, and teratorns, as well as early-arriving immigrant Cyonasua-group procyonids, were driven to extinction during the GABI by competitive exclusion from immigrating placental carnivorans, and that this turnover was abrupt. [94] [95] However, the turnover of South America's predator guild was more complex, with competition only playing a limited role.

In the case of sparassodonts and carnivorans, which has been the most heavily studied, little evidence shows that sparassodonts even encountered their hypothesized placental competitors. [96] [97] [98] Many supposed Pliocene records of South American carnivorans have turned out to be misidentified or misdated. [99] [96] Sparassodonts appear to have been declining in diversity since the middle Miocene, with many of the niches once occupied by small sparassodonts being increasingly occupied by carnivorous opossums, [100] [101] [102] [103] [104] which reached sizes of up to roughly 8 kg (

17 lbs). [101] Whether sparassodonts competed with carnivorous opossums or whether opossums began occupying sparassodont niches through passive replacement is still debated. [104] [103] [102] [101] Borhyaenids last occur in the late Miocene, about 4 Ma before the first appearance of canids or felids in South America. [97] Thylacosmilids last occur about 3 Ma ago and appear to be rarer at pre-GABI Pliocene sites than Miocene ones. [96]

In general, sparassodonts appear to have been mostly or entirely extinct by the time most nonprocyonid carnivorans arrived, with little overlap between the groups. Purported ecological counterparts between pairs of analogous groups (thylacosmilids and saber-toothed cats, borhyaenids and felids, hathliacynids and weasels) neither overlap in time nor abruptly replace one another in the fossil record. [94] [97] Procyonids dispersed to South America by at least 7 Ma ago, and had achieved a modest endemic radiation by the time other carnivorans arrived (Cyonasua-group procyonids). However, procyonids do not appear to have competed with sparassodonts, the procyonids being large omnivores and sparassodonts being primarily hypercarnivorous. [105] Other groups of carnivorans did not arrive in South America until much later. Dogs and weasels appear in South America about 2.9 Ma ago, but do not become abundant or diverse until the early Pleistocene. [96] Bears, cats, and skunks do not appear in South America until the early Pleistocene (about 1 Ma ago or slightly earlier). [96] Otters and other groups of procyonids (i.e., coatis, raccoons) have been suggested to have dispersed to South America in the Miocene based on genetic data, but no remains of these animals have been found even at heavily sampled northern South American fossil sites such as La Venta (Colombia), which is only 600 km from the Isthmus of Panama. [106] [105] [107] [108]

Other groups of native South American predators have not been studied in as much depth. Terror birds have often been suggested to have been driven to extinction by placental carnivorans, though this hypothesis has not been investigated in detail. [109] [110] Titanis dispersed from South America to North America against the main wave of carnivoran migrations, being the only large native South American carnivore to accomplish this. [110] However, it only managed to colonize a small part of North America for a limited time, failing to diversify and going extinct in the early Pleistocene (1.8 Ma ago) the modest scale of its success has been suggested to be due to competition with placental carnivorans. [111] Terror birds also decline in diversity after about 3 Ma ago. [96] At least one genus of relatively small terror birds, Psilopterus, appears to have survived to as recently as about 96,000 years ago. [112] [113]

The native carnivore guild appears to have collapsed completely roughly 3 Ma ago (including the extinction of the last sparassodonts), not correlated with the arrival of carnivorans in South America, with terrestrial carnivore diversity being low thereafter. [96] [114] This has been suggested to have opened up ecological niches and allowed carnivorans to establish themselves in South America due to low competition. [105] [115] [116] A meteor impact 3.3 million years ago in southern South America has been suggested as a possible cause of this turnover, but this is still controversial. [117] [114] A similar pattern occurs in the crocodilian fauna, where modern crocodiles (Crocodylus) dispersed to South America during the Pliocene and became the dominant member of crocodilian communities after the late Miocene extinction of the previously dominant large native crocodilians such as the giant caiman Purussaurus and giant gharial Gryposuchus, which is thought to be related to the loss of wetlands habitat across northern South America. [118] [119]

Whether this revised scenario with a reduced role for competitive exclusion applies to other groups of South American mammals such as notoungulates and litopterns is unclear, though some authors have pointed out a protracted decline in South American native ungulate diversity since the middle Miocene. [120] Regardless of how this turnover happened it is clear that carnivorans benefitted from it. Several groups of carnivorans such as dogs and cats underwent an adaptive radiation in South America after dispersing there and the greatest modern diversity of canids in the world is in South America. [121]

The eventual triumph of the Nearctic migrants was ultimately based on geography, which played into the hands of the northern invaders in two crucial respects. The first was a matter of climate. Any species that reached Panama from either direction obviously had to be able to tolerate moist tropical conditions. Those migrating southward would then be able to occupy much of South America without encountering climates that were markedly different. However, northward migrants would have encountered drier and/or cooler conditions by the time they reached the vicinity of the Trans-Mexican Volcanic Belt. The challenge this climatic asymmetry (see map on right) presented was particularly acute for Neotropic species specialized for tropical rainforest environments, which had little prospect of penetrating beyond Central America. As a result, Central America currently has 41 mammal species of Neotropical origin, [n 18] compared to only three for temperate North America. However, species of South American origin (marsupials, xenarthrans, caviomorph rodents, and monkeys) still comprise only 21% of species from nonflying, nonmarine mammal groups in Central America, while North American invaders constitute 49% of species from such groups in South America. Thus, climate alone cannot fully account for the greater success of species of Nearctic origin during the interchange.

The second and more important advantage geography gave to the northerners is related to the land area in which their ancestors evolved. During the Cenozoic, North America was periodically connected to Eurasia via Beringia, allowing repeated migrations back and forth to unite the faunas of the two continents. [n 19] Eurasia was connected in turn to Africa, which contributed further to the species that made their way to North America. [n 20] South America, though, was connected only to Antarctica and Australia, two much smaller and less hospitable continents, and only in the early Cenozoic. Moreover, this land connection does not seem to have carried much traffic (apparently no mammals other than marsupials and perhaps a few monotremes ever migrated by this route), particularly in the direction of South America. This means that Northern Hemisphere species arose within a land area roughly six times greater than was available to South American species. North American species were thus products of a larger and more competitive arena, [n 21] [78] [122] [123] where evolution would have proceeded more rapidly. They tended to be more efficient and brainier, [n 22] [n 23] generally able to outrun and outwit their South American counterparts, who were products of an evolutionary backwater. In the cases of ungulates and their predators, South American forms were replaced wholesale by the invaders, possibly a result of these advantages.

The greater eventual success of South America's African immigrants compared to its native early Cenozoic mammal fauna is another example of this phenomenon, since the former evolved over a greater land area their ancestors migrated from Eurasia to Africa, two significantly larger continents, before finding their way to South America. [48]

Against this backdrop, the ability of South America's xenarthrans to compete effectively against the northerners represents a special case. The explanation for the xenarthrans' success lies in part in their idiosyncratic approach to defending against predation, based on possession of body armor and/or formidable claws. The xenarthrans did not need to be fleet-footed or quick-witted to survive. Such a strategy may have been forced on them by their low metabolic rate (the lowest among the therians). [131] [132] Their low metabolic rate may in turn have been advantageous in allowing them to subsist on less abundant [133] and/or less nutritious food sources. Unfortunately, the defensive adaptations of the large xenarthrans would have offered little protection against humans armed with spears and other projectiles.

At the end of the Pleistocene epoch, about 12,000 years ago, three dramatic developments occurred in the Americas at roughly the same time (geologically speaking). Paleoindians invaded and occupied the New World, the last glacial period came to an end, and a large fraction of the megafauna of both North and South America went extinct. This wave of extinctions swept off the face of the Earth many of the successful participants of the GABI, as well as other species that had not migrated.

All the pampatheres, glyptodonts, ground sloths, equids, proboscids, [134] [135] [73] giant short-faced bears, dire wolves, and machairodont species of both continents disappeared. The last of the South and Central American notoungulates and litopterns died out, as well as North America's giant beavers, lions, dholes, cheetahs, and many of its antilocaprid, bovid, cervid, tapirid and tayassuid ungulates. Some groups disappeared over most or all of their original range, but survived in their adopted homes, e.g. South American tapirs, camelids, and tremarctine bears (cougars and jaguars may have been temporarily reduced to South American refugia also). Others, such as capybaras, survived in their original range, but died out in areas to which they had migrated. Notably, this extinction pulse eliminated all Neotropic migrants to North America larger than about 15 kg (the size of a big porcupine), and all native South American mammals larger than about 65 kg (the size of a big capybara or giant anteater). In contrast, the largest surviving native North American mammal, the wood bison, can exceed 900 kg, and the largest surviving Nearctic migrant to South America, Baird's tapir, can reach 400 kg.

The near-simultaneity of the megafaunal extinctions with the glacial retreat and the peopling of the Americas has led to proposals that both climate change and human hunting played a role. [84] Although the subject is contentious, [136] [137] [138] [139] [140] a number of considerations suggest that human activities were pivotal. [85] [141] The extinctions did not occur selectively in the climatic zones that would have been most affected by the warming trend, and no plausible general climate-based megafauna-killing mechanism could explain the continent-wide extinctions. The climate change took place worldwide, but had little effect on the megafauna in Africa and southern Asia, where megafaunal species had coevolved with humans. Numerous very similar glacial retreats had occurred previously within the ice age of the last several million years without ever producing comparable waves of extinction in the Americas or anywhere else.

Similar megafaunal extinctions have occurred on other recently populated land masses (e.g. Australia, [142] [143] Japan, [144] Madagascar, [145] New Zealand, [146] and many smaller islands around the world, such as Cyprus, [147] Crete, Tilos and New Caledonia [148] ) at different times that correspond closely to the first arrival of humans at each location. These extinction pulses invariably swept rapidly over the full extent of a contiguous land mass, regardless of whether it was an island or a hemisphere-spanning set of connected continents. This was true despite the fact that all the larger land masses involved (as well as many of the smaller ones) contained multiple climatic zones that would have been affected differently by any climate changes occurring at the time. However, on sizable islands far enough offshore from newly occupied territory to escape immediate human colonization, megafaunal species sometimes survived for many thousands of years after they or related species became extinct on the mainland examples include giant kangaroos in Tasmania, [149] [150] giant Chelonoidis tortoises of the Galápagos Islands (formerly also of South America [84] ), giant Dipsochelys tortoises of the Seychelles (formerly also of Madagascar), giant meiolaniid turtles on Lord Howe Island, New Caledonia and Vanuatu (previously also of Australia), [151] [n 24] ground sloths on the Antilles, [154] [155] Steller's sea cows off the Commander Islands [156] and woolly mammoths on Wrangel Island [157] and Saint Paul Island. [158]

The glacial retreat may have played a primarily indirect role in the extinctions in the Americas by simply facilitating the movement of humans southeastward from Beringia to North America. The reason that a number of groups went extinct in North America but lived on in South America (while no examples of the opposite pattern are known) appears to be that the dense rainforest of the Amazon basin and the high peaks of the Andes provided environments that afforded a degree of protection from human predation. [159] [n 25] [n 26]

North American species of South American origin Edit

Distributions beyond Mexico Edit

Extant or extinct (†) North American taxa whose ancestors migrated out of South America and reached the modern territory of the contiguous United States: [n 27]

    (Didelphis virginiana) (nine-banded armadilloDasypus novemcinctus, †D. bellus)
  • Pachyarmatherium leiseyi, an enigmatic armored armadillo relative
  • †Pampatheres (Plaina, [166]Holmesina) – large armadillo-like animals
  • †Glyptodonts (Glyptotherium)
  • †Megalonychid ground sloths (Pliometanastes, Megalonyx)
  • †Megatheriid ground sloths (Eremotherium)
  • †Mylodontid ground sloths (Thinobadistes, Glossotherium, [166]Paramylodon)
  • †Nothrotheriid ground sloths (Nothrotheriops, Nothrotherium) (Erethizon dorsatum, †Erethizon poyeri, †E. kleini) (†Neochoerus pinckneyi, †N. aesopi)
  • Mixotoxodon – a rhino-sized toxodontidnotoungulate[n 28] (Puma concolor) – returning from a South American refugium after North American cougars were extirpated in the Pleistocene extinctions[169] bats [49] bats (Mormoops megalophylla) [50] (†Desmodus stocki, †D. archaeodaptes)

The pampathere †Holmesina septentrionalis

Distributions restricted to Mexico Edit

Extant or extinct (†) North American taxa whose ancestors migrated out of South America, but failed to reach the contiguous United States and were confined to Mexico and Central America: [n 27] [n 29]

  • Hoplosternum punctatum, an armored catfish (Siluriformes: Callichthyidae)
  • Several species of loricariid catfish (Siluriformes: Loricariidae)
    (Crax rubra) [174] (Ramphastidae) (Tinamidae)
  • Additional suboscine birds (Tyranni):
      (Conopophagidae) [164] (Cotingidae) [164] (Formicariidae) [164] and woodcreepers (Furnariidae) [175] (Grallariidae) [164] (Pipridae) [164] (Rhinocryptidae) [164] (Thamnophilidae) [164]
  • Other Neotropical parrots (Arinae)
    • Other opossums (Didelphidae) – 11 additional extant species [n 18] (Cabassous centralis) (Bradypodidae: Bradypus variegatus, B. pygmaeus) (Choloepodidae: Choloepus hoffmanni)
    • †Scelidotheriid ground sloths (Scelidotherium, found in Panama [176] ) (Cyclopedidae: Cyclopes dorsalis)
    • Other anteaters (Myrmecophagidae: Myrmecophaga tridactyla, [n 30]Tamandua mexicana) and Mexican hairy dwarfporcupines (Coendou rothschildi, Sphiggurus mexicanus)
    • Other caviomorph rodents (Caviomorpha) – 9 additional extant species [n 18] (Platyrrhini) – at least 8 extant species [n 18][n 31] (Bassaricyon) are thought to have arisen in the Andes of northwest South America after their procyonid ancestors invaded from the north, before diversifying and migrating back to Central America [179]
    • South American short-faced bears (Tremarctinae: †Arctotherium wingei) are thought to have invaded to as far as the Yucatán after arising in South America from North American ancestors [180]
    • South American canids (Caninae: †Protocyon troglodytes) are thought to have invaded to as far as the Yucatán after arising in South America from North American ancestors [180] bats [51] bats [50] (Furipterus horrens)
    • Other mormoopid bats [50] bats [50] (Noctilio albiventris, Noctilio leporinus)
    • Other phyllostomid bats, [50] including all 3 extant vampire bat species (Desmodontinae) bats [50] (Thyroptera discifera, Thyroptera tricolor)

    South American species of North American origin Edit

    Extant or extinct (†) South American taxa whose ancestors migrated out of North America: [n 27]

    South America: Physical Geography

    Encyclopedic entry. South America is a continent of extremes. It is home to the world's largest river (the Amazon) as well as the world's driest place (the Atacama Desert).

    Biology, Earth Science, Geology, Meteorology, Geography, Physical Geography

    South America, the fourth-largest continent, extends from the Gulf of Darién in the northwest to the archipelago of Tierra del Fuego in the south.

    South America&rsquos physical geography, environment and resources, and human geography can be considered separately.

    South America can be divided into three physical regions: mountains and highlands, river basins, and coastal plains. Mountains and coastal plains generally run in a north-south direction, while highlands and river basins generally run in an east-west direction.

    South America&rsquos extreme geographic variation contributes to the continent&rsquos large number of biomes. A biome is a community of animals and plants that spreads over an area with a relatively uniform climate.

    Within a few hundred kilometers, South America&rsquos coastal plains&rsquo dry desert biome rises to the rugged alpine biome of the Andes mountains. One of the continent&rsquos river basins (the Amazon) is defined by dense, tropical rain forest, while the other (Paraná) is made up of vast grasslands.

    With an unparalleled number of plant and animal species, South America&rsquos rich biodiversity is unique among the world&rsquos continents.

    Mountains & Highlands

    South America&rsquos primary mountain system, the Andes, is also the world&rsquos longest. The range covers about 8,850 kilometers (5,500 miles). Situated on the far western edge of the continent, the Andes stretch from the southern tip to the northernmost coast of South America. There are hundreds of peaks more than 4,500 meters (15,000 feet) tall, many of which are volcanic.

    The highest peak in the Andes, Aconcagua, stands at 6,962 meters (22,841 feet) and straddles the Argentina-Chile border. Aconcagua is the tallest mountain outside Asia.

    High plateaus are also a feature of the Andes. The altiplano of Peru and Bolivia, for example, has an elevation of about 3,700 meters (12,300 feet). The Patagonia region of Argentina and Chile consists of lower-elevation plateaus and rugged glaciers.

    Most plants in the alpine biome are small, and their leaves are stiff and strong to protect them from frost and drought. The largest herb in the world, Puya raimondii, is known as the Queen of the Andes. A Puya raimondii can live for 100 years and can grow to more than 9 meters (30 feet) tall. The leaves of this endangered species all grow from one woody stem, allowing moisture to run down the leaves to the base of the plant.

    Outside the Andes, South America has two principal highland areas: the Brazilian Highlands and the Guiana Highlands. Located south of the Amazon River in Brazil, the Brazilian Highlands are made up of low mountains and plateaus that rise to an average elevation of 1,006 meters (3,300 feet). The Guiana Highlands are located between the Amazon and Orinoco Rivers. The heavily forested plateau of the Guiana Highlands covers southern Venezuela, French Guiana, Guyana, northern Brazil, and a portion of southeastern Colombia.

    River Basins

    South America has three important river basins: the Amazon, Orinoco, and Paraguay/Paraná.

    The Amazon River basin has an area of almost 7 million square kilometers (2.7 million square miles), making it the largest watershed in the world. The basin, which covers most of northern South America, is fed by tributaries from the glaciers of the Andes. Every second, the Amazon River empties 209,000 cubic meters (7,381,000 cubic feet) of freshwater into the Atlantic Ocean.

    The Amazon River is the life force of the equally vast Amazon rain forest, which makes up about half of the rain forest of the entire planet. This tropical biome has as many as 100 different tree species on a single acre, including the rubber tree, silk cotton tree, and Brazil nut tree. Other important plant species include palms, ferns, and ropelike vines known as lianas that network throughout the rain forest&rsquos dense canopy.

    The diversity of animal life in the Amazon rain forest is unsurpassed in the rest of the world. The rain forest is perfectly suited for arboreal, or tree-living, animals. More than 2 million species of insects are native to the region, including hundreds of spiders and butterflies. Primates are abundant&mdashhowler monkeys, spider monkeys, and capuchin monkeys&mdashalong with sloths, snakes, and iguanas. Thousands of native birds include brightly colored macaws, parrots, toucans, and parakeets.

    The Orinoco River flows north of the Amazon. The Orinoco flows in a giant arc for more than 2,736 kilometers (1,700 miles), originating in the Guiana Highlands of northern Brazil and discharging in the Atlantic Ocean in Venezuela. The Orinoco River basin covers an area of about 948,000 square kilometers (366,000 square miles) and encompasses approximately 80 percent of Venezuela and 25 percent of Colombia.

    A vast savanna or grassland region, known as the Llanos, is the primary biome of the Orinoco River basin. The Llanos is primarily made up of grasses. Swamp grasses, sedges, and bunchgrass are found in wet, low-lying areas. Carpet grass is found in the higher and drier elevations.

    Like most grassland biomes, the Llanos is the perfect habitat for many bird species, including the scarlet ibis, bellbird, and umbrellabird. Important river species include the piranha, electric eel, and the Orinoco crocodile, which can reach a length of more than 6 meters (20 feet).

    The Paraguay/Paraná River basin covers almost 2.8 million square kilometers (1,081,000 square miles), which is much of southeastern Brazil and Bolivia, Paraguay, and northern Argentina. The Paraná River includes Iguazu Falls, a massive series of waterfalls that extend for 2.7 kilometers (1.7 miles).

    Along with the Uruguay River, the Paraná River empties into the Rio de la Plata estuary between Argentina and Uruguay. The Rio de la Plata is the most populated region of both countries. The capital cities of Buenos Aires, Argentina, and Montevideo, Uruguay, practically face each other across the estuary.

    The Paraguay/Paraná River basin supplies water to the plains biome, or Pampas, of South America. The Pampas have rich, fertile soil and predictable rainfall patterns. They are the most important grazing and cropland areas on the continent.

    Coastal Plains

    A coastal plain is an area of low, flat land next to a seacoast. South American coastal plains are found on the northeastern coast of Brazil, on the Atlantic Ocean, and the western, Pacific coast of Peru and Chile. The coastal plains of northeastern Brazil are extremely dry. The Brazilian Highlands act as a wedge that pushes moist sea winds away from the coastal plains.

    The western coastal plains are also extremely dry. They are trapped between the cold Peru Current to the west and the Andes Mountains to the east. The Peru Current brings cold water to the Pacific coast of Peru and Chile. This cold surface water results in thermal inversion: cold air at sea level and stable, warmer air higher up. Thermal inversion produces a thick layer of clouds at low altitudes. These low-lying clouds blanket much of the Pacific coast of South America. They do not allow precipitation to form.

    The Atacama Desert is part of the western coastal plain. The Atacama is considered the driest region in the world. The average rainfall is about 1 millimeter (0.04 inches) a year, and some parts of the Atacama have never had rain in recorded history.

    Very few plants grow in this desert. Even bacteria, insects, and fungi are scarce. Larger animal species are also rare, and include the grey fox, a type of deer called the huemul, and the viscacha&mdashthe largest member of the chinchilla family. Ocean birds, such as penguins, cormorants, and pelicans, are found on the desert coast. While Atacama lacks flora and fauna, it is a rich source of copper and a chief source of revenue for the Chilean economy.

    South America is a continent of extremes. It is home to the world's largest river (the Amazon) as well as the world's driest place (the Atacama Desert).

    National and Regional Chronicles

    By the late twentieth century, the United States and Canada had long since divided sovereignty over North America between them. Christianity was the predominant religion in both countries, and in both it exhibited characteristics suggesting the political and cultural ambience of North America. At the same time, each country showed marked differences from its neighbor in the forms its Christianity assumed.

    Canadian Christianity

    Because of their special history, Canadians generally thought of themselves as two nations — groups bound by ties of blood, tradition, and ethnic identity — in one political state. The political balance of power between French Canadians and English Canadians had a religious counterpart in the more or less equal division between Roman Catholic and Protestant Christians (although a large proportion of Catholics were English-speaking and not French at all). Protestant Christians comprised fewer denominations than in the United States, historically most belonging to the three or four biggest churches. Hence, it is fair to say that Canadian Christianity was both more and less plural than Christianity in the United States.

    Canadian Christianity was more plural because the concentration of Christians into fewer religious groups fostered greater visibility and leverage for denominations with sufficient power and status in the community to count. But Canadian Christianity was also less plural than its American counterpart, for the obvious reason that there were fewer groups in absolute numbers, but also because of an ecumenism especially apparent in Protestant Christianity. It was less plural, too, because of the subtle Erastianism that encouraged all denominations to uphold a central cultural order. Christianity in Canada tended to be "social" Christianity, more conservative than in the United States and less rigid in its boundary between church and state.

    Mission-minded and voluntaryistic like the American Christian churches, the Canadian denominations had worked on a huge geographical scale, and so — perhaps more than and ahead of their country's politicians — they thought in terms of the North American continent as a whole. Moreover, with the imposing strength of Roman Catholicism before them, Canadian Protestants were particularly urged in cooperative directions. Thus, in some sense they provided the public unity that the state could not give because of its divisions between English and French. Much more than Christianity in the United States, Canadian Christianity maintained its ties with the past, favoring continuity and tradition over religious change and novelty.

    Finally, Canadians overwhelmingly counted themselves denominational Christians, exceeding even the high American church membership (nearly 70 percent of the people) in the late twentieth century. At the beginning of the twentieth century, 90 percent of Canadians belonged to six major Christian groups (including as the largest the Roman Catholic). By the 1960s, with some substitutions, the figure was higher still, and by the early 1970s over three-quarters of the population were Roman Catholic, United Church, or Anglican Church members.

    American Christianity

    The Puritan ethos left its mark on American religion, and numerical, political, and cultural balance made the United States distinctly Protestant. Although the nation was far more plural than Canada in the number of its Christian groups (a conservative estimate includes more than two hundred), public Protestantism meant that, with less overt cooperation between church and state, the country could become in some ways far more Christian, far less secular, than its northern neighbor.

    Thus, while the Canadian system accommodated itself to the support of denominational schools, in the United States the nineteenth-century public schools openly taught Protestant Christianity. Similarly, even as Puritanism faded into other denominational forms, its spirit remained to transform public and political life. Manifest destiny and political imperialism became the harvest of the Puritan past.

    Explicitly present in Puritanism, millennialism resurfaced time and again — in liberal expectations of a new era, in sectarian beliefs that the millennium had already come or was just about to break, in fundamentalist announcements of the signs of the swift return of Christ. Nationally, too, political millennialism suffused foreign and domestic policy, so that wars were generally read as epochal events that would determine the future of the nation and even the world.

    Tied to this generalized cultural millennialism, ultraism flourished in American social history. The ultraism was evident in the moralistic crusades — which were more strident in the United States than in Canada — over antislavery, temperance, civil rights, and other social issues. Yet for all the mass emotion, the rhetoric of religious individualism became uppermost in the United States. This rhetoric went hand in hand with the ideology of newness and evangelical mission and hand in hand, too, with a pronounced ahistoricism and, in restorationist sentiment, a willingness to skip over long centuries of Christian history. Linked to a search for religious simplicity and sometimes to anti-intellectualism, restorationist movements expressed in institutional form a general spirit in American Christianity.

    Certainly, as early as the mid-nineteenth century, Roman Catholicism was the single largest Christian denomination in the United States, and by 1983 it included some 29 percent of the population. But, with a different history and a lesser size, Catholicism never achieved the impact on American culture that had been its birthright in Canada. Simultaneously more and less established than in Canada, public Christianity continued to be Protestant Christianity.

    Finally, this public Christianity assumed explicitly political form in what many scholars have called civil religion. While the Enlightenment ideology present at the time of the American Revolution encouraged a form of religious nationalism that was not specifically Christian, later a public alliance between gospel and flag became commonplace. By the 1970s and 1980s, a new Christian Right was working to shape political events. Conservative Christians were probably the fastest-growing Christian groups in Canada as in the United States, but again, because of the different histories of the two countries, they could not capture the public space in Canada in the same way as in the United States. Hence, in American religion, public Protestantism, civil religion, and cultural religion became aspects of the same center.

    Regional Christianity

    Living together in one area, Christian peoples may share a common history as well as a common religion. Likewise, they sometimes develop ties that, in effect, constitute them as a new "particular people." European sectarian groups that settled in North America offered striking cases of the growth of such religious regionalism. Rural places and urban centers alike often assumed the character of a religious and ethnic group. Meanwhile, more diffused throughout larger areas, identifiable forms of regional Christianity flourished. This was clearly true in the French Canadian Catholicism of the province of Quebec, but it was also true in, for example, the Eastern Cherokee Christianity of western North Carolina after the Indian Removal of 1838. The pattern could be noticed distinctly in the fundamentalist Protestantism of southern Appalachia, and it was strikingly present in black religion as, in sections of the American South, it joined to its Christianity inherited African thought forms and indigenous folk religion.

    The larger North American landscape

    In the end, however, North American Christianity should be seen from a continental perspective. With its voluntaryism, activism, and moralism, it has been generally evangelistic in tone. The call to mission clearly gave it a distinct identity: Roman Catholic and, more, Eastern Orthodox strains of mystical piety never made their mark on Christian culture as a whole. Denominational in organization, the essence of North American Christianity has been at once its plurality and its seeking for a genuine pluralism, a state of pleased acceptance of the plural situation. At the same time, North American Christianity modified the plurality to reflect political and national needs for unity.

    With the second half of the twentieth century, religion in North America encountered the increasing secularization of culture. Although in both the United States and Canada Christian church membership included the large majority, it also seemed that, except for the fundamentalist political thrust of the New Right, Christianity had a diminished connection with everyday life. In a certain sense, the mission-minded evangelical ethos seemed more a style or habit than a substantive transformer of the world. On the other hand, North American Christianity has perhaps grown more modest, chastened by a new awareness of the danger of cultural imperialism. At the start of the twenty-first century, it has turned inward to find spiritual roots in its biblical heritage and outward to listen to the words and messages of non-Christian others at home and abroad.

    Now You Know: Why Are There Two Dakotas?

    The Dakota Territory was formed in 1861&mdashincluding what we now think of as North Dakota and South Dakota, as well as parts of Wyoming and Montana&mdashand took on the boundaries of the two Dakotas in 1868. It was entirely expected that such territories would eventually join the U.S. as states after meeting certain requirements, like hitting a population count of more than 60,000 and drafting a state constitution.

    So why did the two halves of the territory reach statehood separately?

    Steven Bucklin, a professor of history at the University of South Dakota, points to regional differences in trade routes and population size as the two main factors. Those differences, with the addition of some territorial government politics, meant the populations felt some resentment for each other. Or, as Kimberly Porter, a history professor at the University of North Dakota, puts it, “the south half did not like the north half.”

    (While we’re going to focus on why there are two Dakotas, it’s worth noting that they’re not the only states to share a name&mdashthe Carolinas separated in the first half of the 18th century, and West Virginia split from Virginia during the civil war because delegates from the western part of the state opposed secession.)

    In terms of population size, the two parts of the territory were different from the beginning. There were always more people in the southern part of Dakota territory, which grew from about 10,000 in 1870 to about over 98,000 in 1880. By that point, according to the U.S. census, northern Dakota was home to only about 37,000 people. That meant that southern Dakota had the population necessary to join as a state, all on its own, years before the northern part of the state did.

    Perhaps not coincidentally, there was also a bit of a personality difference between the two regions: the south thought the north was a bit disreputable, Porter says, “too much controlled by the wild folks, cattle ranchers, fur traders” and too frequently the site of conflict with the indigenous population.

    Meanwhile, a year after the Dakota territory was formed, the Homestead Act passed. This new law encouraged settlement in the West, as did railroads that connected new farmers to markets for their crops. But the trade routes supported by these railroads connected North and South Dakota to different commercial hubs, says Bucklin. The northern part of Dakota territory became more closely tied to Minneapolis-St. Paul, via Fargo and Bismarck. In contrast, the southern counties along the Missouri and Big Sioux rivers were more closely tied by trade to Sioux City, and from there to Omaha or over to Chicago. These diverging economic ties left residents of different parts of the territory less connected to each other.

    In terms of politics, the way the territory system was set up, legislators were appointed by the federal government in Washington, D.C., and tended to remain in the region only while they served their terms. The larger population of the southern region began to resent those “carpetbaggers,” Bucklin says, but the northerners tended to emphasize that it was cheaper to be a territory, with the feds funding a wide range of state functions. It didn’t help that the state legislators were sometimes notoriously corrupt&mdashlike Nehemiah Ordway, who moved the capital in 1883. “He essentially helped steal the state territorial capital from Yankton, now in South Dakota, to Bismarck, now in North Dakota” says Porter. The capital grab, which moved the capital even farther from the majority of the population, only fueled more resentment from the south.

    By that point, South Dakotans had the necessary population for statehood and quickly moved to become an independent state. However, many attempts to form an independent state failed, Porter says, as the federal response was “either do it as one very large state, Dakota, or wait until you have enough people on both sides to be two separate states.”

    That second option would play out before the decade was over. But why did they both choose to keep the name “Dakota”?

    South Dakota wanted to be called simply “Dakota” Porter says, and “then the northern half would become either the territory of Pembina, which is a community right on the Canadian border, or else they thought we could be called the territory and ultimately state of Lincoln, as in the president.” But Porter says Dakota had already become a trademark of sorts&mdasha source of quality products, “like California raisins or Florida orange juice”&mdashand neither side wanted to give it up.

    On Nov. 2, 1889 President Benjamin Harrison signed the papers to admit North and South Dakota as two separate states, along with Montana and Washington. Though North Dakota is generally considered the 39th state to South Dakota’s 40th state, it’s actually unclear which one was admitted first says Bucklin: “apparently President Harrison shuffled the paperwork first,” and signed the documents blindly.

    North America: Resources

    Encyclopedic entry. North America benefits greatly from its fertile soils, plentiful freshwater, oil and mineral deposits, and forests.

    Earth Science, Geology, Engineering, Geography, Human Geography, Physical Geography

    North America, the third-largest continent, extends from the tiny Aleutian Islands in the northwest to the Isthmus of Panama in the south.

    North Americas physical geography, environment and resources, and human geography can be considered separately.

    North America benefits greatly from its fertile soils, plentiful freshwater, oil and mineral deposits, and forests. With a strong domestic and export economy focused on this abundant array of natural resources, North America has become one of the most developed regions in the world.


    From the freezing Arctic to the tropical jungles of Central America, North America enjoys more climate variation than any other continent. Almost every type of ecosystem is represented somewhere on the continent, from coral reefs in the Caribbean to the ice sheet in Greenland. These differences contribute to North Americas variety of agricultural industries, which are often divided by climate zone: tropical zone, subtropical zone, cool temperate zone, and dry zone.

    In the tropical zones of North America, farmers harvest oranges, sugar cane, coffee, cocoa, and bananas. These crops grow on coastal plains and humid mountain slopes. Cotton and hemp are cultivated in the warmer and drier intermediate climate zone. These crops are important exports for Central American countries.

    Fruits, vegetables, cotton, and tobacco are predominant in the warm, subtropical zones of northern Mexico and the United States. Important agricultural areas in this zone include the Rio Grande Valley (citrus fruits) in the U.S. state of Texas and Mexico, Californias Central Valley (fruits and vegetables), the Gulf Coastal Plain (vegetables), and the sandy valleys of the Appalachians (cotton and tobacco). These areas benefit from ample rain and warm air currents.

    Agriculture in North Americas tropical and subtropical zones is threatened by monoculture. Monoculture is the practice of growing one crop in an area over a long period of time. Monoculture is a risky way of farming for two reasons. First, the soil may lose its nutrients. The nitrogen and phosphates in the soil do not have time to accumulate if the field is not allowed to be fallow, or rest. Planting other, less-intensive crops can also help the soil recover its natural nutrients. The second reason monoculture puts crops at risk is the possibility of disease. A disease affecting a single species of plant could devastate an entire crop, and the community's livelihood. Planting a variety of crops minimizes the risk of disease.

    Farmers and agribusinesses combat the threats of monoculture with the use of fertilizers and pesticides. Fertilizers replenish nutrients such as phosphates and nitrates to the soil. Pesticides target diseases brought by pests of a single plant. However, extensive use of fertilizers and pesticides can have a harmful impact on the environment. Runoff from agricultural fields can pollute rivers, lakes, and the ocean.

    The continents cool temperate zones are ideal for hardy fruits, such as apples and peaches. Important agricultural areas in this climate include the Finger Lakes region of New York in the U.S. the Niagara Peninsula in the Canadian province of Ontario the Columbia River basin in the U.S. state of Washington and the Canadian province of British Columbia and the valleys of the Appalachians. These areas benefit from excellent drainage and predictable, established frosts.

    The Dairy Belt, Corn Belt, and Wheat Belt are three agricultural areas in the continents cool temperate zones.

    Dairy animals, including cows, goats, and sheep, feed on the hay and hardy small grains that thrive in New England and the Great Lakes-St. Lawrence region along the Atlantic coast. This is the Dairy Belt.

    The Corn Belt, located between the Ohio River and the lower Missouri River, receives ample water and strong summer sun, ideal for corn and soybeans.

    West of the Corn Belt, the Wheat Belt stretches from the U.S. state of Kansas through the Canadian Prairie Provinces of Alberta, Saskatchewan, and Manitoba. This vast area of the Great Plains allows wheat to be cultivated in both winter and spring.

    Dry zones, common in the southwestern U.S. and northern Mexico, are ideally suited for livestock ranching. Ranches with thousands of cattle are common in this region. Traditionally, livestock fed on locally grown fodder such as prairie grasses. However, irrigation for fruit and cotton farming has drained water supplies in the region. Native grasses cannot nourish the huge herds of livestock kept by ranchers. Cattle, sheep, hogs, and other livestock are less likely to graze than to eat corn-based feed. In fact, most of the corn grown in the Corn Belt is feeder corn used for livestock feed.

    Forestry is a major economic activity for much of North America. In the United States, the timber industry is strong in the Pacific Northwest, the Gulf states, and South Atlantic coastal plains. In Canada, forestry is a major industry in the provinces of Quebec, Ontario, and British Columbia.

    Forestry is the management, cultivation, and harvesting of trees and other vegetation in forests. In the Pacific Northwest, for instance, logging companies harvest cedar, fir, and spruce trees. Lumber from these trees is exported around the world for construction. Some of the continents largest paper mills are found in these temperate rain forests. In addition to paper, paper mills produce cardboard and fiberboard.

    Overharvesting of timber is a concern throughout North America. The reduction of forested land reduces biodiversity and threatens the longevity of the timber industry. The logging industry and local governments must work together to develop sustainable plans to harvest timber.

    The Mexican government, for example, created the ProArbol (pro-tree) campaign with the objectives of conserving and restoring forests. The campaign pledges to plant more than 250 million trees in urban and rural Mexico. ProArbol also works to ensure that Mexican forests positively influence biodiversity and human health.

    Extractive activities, such as mining and drilling, dominate the North American economy. Mining provides billions of dollars and millions of jobs throughout the continent. North America is a leading producer of coal, used in energy production bauxite, used to create aluminum iron and copper, both used in construction and nickel, used to create steel, which North American companies export around the world. Gold and silver mines operate in the western part of the continent. Visitors to Crater of Diamonds State Park, a mine in the U.S. state of Arkansas, can search for their own diamonds.

    Extractive activities have been a major part of the economies of North America for hundreds of years. For example, gold mining helped spur development in the U.S. states of California and Alaska in the 19th century.

    Coal remains a primary industry for the U.S., and is often linked with states near the Appalachians. Coal is a type of sedimentary rock found deep underground, formed from the remains of ancient plants. When burned, coal is an excellent source of energy and is mostly used as fuel for electricity-generating power plants. Coal can be mined underground or in large, open pits.

    Mining is a dangerous industry. Coal is combustible, meaning it catches fire and explodes easily. Coal dust is toxic when breathed for long periods of time. Mines are vulnerable to collapse. Mining accidents have led companies and governments to pursue regulations that ensure greater safety for miners. In 2006, for instance, a coal mine in Sago, West Virginia, exploded. Thirteen miners were trapped hundreds of meters below ground. Only one miner survived. The so-called Sago mine disaster prompted calls for greater communication and safety technology to be employed at mining sites throughout North America.

    Coal mining can also have a negative impact on the environment. Mountaintop removal mining (MTR) has eliminated entire mountain ecosystems in the Appalachians. This type of mining also results in coal waste products being stored near public land. Improper storage of these waste products has damaged ecosystems and threatened human health. In 2008, a massive spill resulted in 1.1 billion gallons of coal slurry being released near Kingston, Tennessee. The spill damaged homes and entered into the Emory and Clinch Rivers, killing large fish populations and threatening water supplies.

    North America is home to vast deposits of oil and natural gas, which are drilled for energy and fuel. Oil and gas extraction are key elements of North Americas economy. The United States, Canada, and Mexico are among the worlds top oil producers.

    The Athabasca tar sands, in the Canadian province of Alberta, are the worlds largest reservoir of heavy crude oil. More than 20 national and international extraction projects are established in the Athabasca tar sands. The extraction and processing of crude oil, however, destroys the areas boreal forests and diverts an incredible volume of water from local rivers. The heavy crude oil from tar sands also emits 20 percent more carbon dioxide than emissions from light crude oil.

    Oil and gas extraction is the dominant industry around the Gulf and Arctic regions of North America. Mexico leads other North American countries as one of the top oil exporters in the world, largely because of its reserves in and around the Gulf. (Although both the United States and Canada produce more oil than Mexico, they also consume far more. Both countries are mostly importers, not exporters, of oil and natural gas.)

    Oil and natural gas, like coal, are nonrenewable resources. Global demand for fossil fuels has caused multinational corporations to drill in remote and dangerous regions. Scientists and engineers have developed more complex technology to search for deposits. Oil companies are forced to drill deeper and in more remote areas to extract these resources. The impact of these extractive activities is unknown.

    However, the Deepwater Horizon oil spill in April 2010 has put into question the safety and sustainability of high-tech extractive industries. Deepwater Horizon was an offshore oil rig in the Gulf of Mexico, capable of drilling to depths of 9,100 meters (30,000 feet). The rig exploded, killing 11 workers and causing a massive oil spill that took months to control. The impact on the environment was felt in the U.S. from Texas to Florida.

    The Built Environment

    North Americas high level of economic development has promoted the construction of megacities, engineering marvels, and advanced infrastructure.

    A megacity is usually defined as an urban area with at least 10 million people. Mexico City, Mexico New York, New York and Los Angeles, California, are North Americas megacities.

    With 21.2 million people, Mexico City is the largest metropolitan area in the Americas. Industrial growth caused a demographic boom during the last half-century, increasing the areas population from 3 million people in 1950 to its present numbers. As with many megacities, Mexico City is currently experiencing slower growth than in the past. The economy has shifted from manufacturing to the service industry, which includes tourism, education, banking, and sales. More people are moving out of the city itself and into the suburbs.

    Mexico City is built on a swampy series of islands in a valley surrounded by volcanoes. As the population boomed, the areas delicate geology led to problems with flooding, runoff, wastewater management, pollution, and earthquakes.

    Los Angeles, California, is one of the fastest-growing cities on the continent. L.A. is the second largest city in the United States, with 3.83 million people in 2008 the entire metropolitan area has more than 15 million people. The city is known as the Entertainment Capital of the World, with many motion picture, television, and music production studios established there. Los Angeles is also considered a majority-minority city, as its racial composition is less than 50 percent white. According to U.S. Census figures, Angelenos of Latino origin account for 48.4 percent of the population.

    Toronto, Ontario, Canada, is also considered one of the most ethnically diverse cities in the world. More than 50 percent of its population was born outside of Canada. The citys diverse community, low crime rates, clean environment, and high standard of living make it one of the worlds most livable cities.

    Engineering marvels have defined North America over the last century. The Panama Canal, completed in 1914, is one of the most important waterways in the world. Its 80-kilometer (50 mile) length connects the Atlantic and Pacific Oceans through the Isthmus of Panama, making ship voyages dramatically shorter. Ships travelling from the west coast to the east coast of the United States, for example, cut their voyage by 8,000 nautical miles because they are not required to round Cape Horn at the southern tip of South America.

    The Hoover Dam, completed in 1936, is another of North Americas engineering milestones. Located on the Colorado River on the border between the U.S. states of Arizona and Nevada, the Hoover Dam creates Lake Mead, one of the largest manmade lakes in the world. The dam is used for flood control, electric power, irrigation, and water supplies.

    While it has contributed greatly to the development of the southwestern U.S., the Hoover Dam has also negatively impacted the Colorado River, its tributaries, and surrounding ecosystems. Construction of the dam basically eliminated the Colorado Delta ecosystem, as almost no water reaches the rivers mouth. Communities in the Mexican state of Baja California are also prevented from using the rivers water supplies.

    Cities and economic development have spurred North American engineers and architects to construct some of the worlds most striking buildings. Completed in 1976, Torontos CN Tower is the tallest freestanding structure in the Western Hemisphere, standing at 553 meters (1,815 feet). All major Canadian radio stations, as well as wireless service providers, use the CN Tower for transmission.

    North Americas advanced infrastructure has allowed populations, services, and industries to prosper across the continent. With the first underground line opened in 1904, the New York City subway system is one of the oldest and most extensive public transportation systems in the world. It now has more than 450 stations, more than 354 kilometers (220 miles) of track, and delivered more than 1.575 billion rides in 2009.

    Other infrastructure systems transport goods. Mexicos state-owned petroleum company, Pemex, transports crude oil and natural gas through more than 453 pipelines spanning 4,667 kilometers (2,900 miles). Pemex is one of the largest companies in the world.

    North America benefits greatly from its fertile soils, plentiful freshwater, oil and mineral deposits, and forests.

    Map by the National Geographic Society

    Most Renewable Electricity Produced
    Belize (96.7% hydropower, biomass)

    Population Density
    57 people per square kilometer

    Largest Watershed
    Mississippi River (3 million square kilometers/1.15 million square miles)

    Highest Elevation
    Denali, Alaska, United States (6,190 meters/20,310 feet)

    Largest Urban Area
    New York City, United States (23.7 million people)


    A continent is one of Earth&rsquos seven main divisions of land. The continents are, from largest to smallest: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.

    Earth Science, Geology, Geography, Physical Geography

    This lists the logos of programs or partners of NG Education which have provided or contributed the content on this page. Leveled by

    A continent is one of Earth&rsquos seven main divisions of land. The continents are, from largest to smallest: Asia, Africa, North America, South America, Antarctica, Europe, and Australia.

    When geographers identify a continent, they usually include all the islands associated with it. Japan, for instance, is part of the continent of Asia. Greenland and all the islands in the Caribbean Sea are usually considered part of North America.

    Together, the continents add up to about 148 million square kilometers (57 million square miles) of land. Continents make up most&mdashbut not all&mdashof Earth&rsquos land surface. A very small portion of the total land area is made up of islands that are not considered physical parts of continents. The ocean covers almost three-fourths of Earth. The area of the ocean is more than double the area of all the continents combined. All continents border at least one ocean. Asia, the largest continent, has the longest series of coastlines.

    Coastlines, however, do not indicate the actual boundaries of the continents. Continents are defined by their continental shelves. A continental shelf is a gently sloping area that extends outward from the beach far into the ocean. A continental shelf is part of the ocean, but also part of the continent.

    To geographers, continents are also culturally distinct. The continents of Europe and Asia, for example, are actually part of a single, enormous piece of land called Eurasia. But linguistically and ethnically, the areas of Asia and Europe are distinct. Because of this, most geographers divide Eurasia into Europe and Asia. An imaginary line, running from the northern Ural Mountains in Russia south to the Caspian and Black Seas, separates Europe, to the west, from Asia, to the east.

    Building the Continents

    The Earth formed 4.6 billion years ago from a great, swirling cloud of dust and gas. The continuous smashing of space debris and the pull of gravity made the inside of Earth heat up. As the heat increased, some of Earth&rsquos rocky materials melted and rose to the surface, where they cooled and formed a crust. Heavier material sank toward Earth&rsquos center. Eventually, the earth came to have three main layers: the core, the mantle, and the crust.

    The crust and the top portion of the mantle form a rigid shell around the earth that is broken up into huge sections called tectonic plates. The heat from inside the earth causes the plates to slide around on the molten mantle. Today, tectonic plates continue to slowly slide around the surface, just as they have been doing for hundreds of millions of years. Geologists believe the interaction of the plates, a process called plate tectonics, contributed to the creation of continents.

    Studies of rocks found in ancient areas of North America have revealed that the oldest known pieces of the continents began to form nearly four billion years ago, soon after Earth itself formed. At that time, a primitive ocean covered Earth. Only a small fraction of the crust was made up of continental material. Scientists theorize that this material built up along the boundaries of tectonic plates during a process called subduction. During subduction, plates collide, and the edge of one plate slides beneath the edge of another.

    When heavy oceanic crust subducted toward the mantle, it melted in the mantle&rsquos intense heat. Once melted, the rock became lighter. Called magma, it rose through the overlying plate and burst out as lava. When the lava cooled, it hardened into igneous rock.

    Gradually, the igneous rock built up into small volcanic islands above the surface of the ocean. Over time, these islands grew bigger, partly as the result of more lava flows and partly from the buildup of material scraped off descending plates. When plates carrying islands subducted, the islands themselves did not descend into the mantle. Their material fused with that of islands on the neighboring plate. This made even larger landmasses&mdashthe first continents.

    The building of volcanic islands and continental material through plate tectonics is a process that continues today. Continental crust is much lighter than oceanic crust. In subduction zones, where tectonic plates interact with each other, oceanic crust always subducts beneath continental crust. Oceanic crust is constantly being recycled in the mantle. For this reason, continental crust is much, much older than oceanic crust.

    Wandering Continents

    If you could visit Earth as it was millions of years ago, it would look very different. The continents have not always been where they are today. About 480 million years ago, most continents were scattered chunks of land lying along or south of the Equator. Millions of years of continuous tectonic activity changed their positions, and by 240 million years ago, almost all of the world&rsquos land was joined in a single, huge continent. Geologists call this supercontinent Pangaea, which means &ldquoall lands&rdquo in Greek.

    By about 200 million years ago, the forces that helped form Pangaea caused the supercontinent to begin to break apart. The pieces of Pangaea that began to move apart were the beginnings of the continents that we know today.

    A giant landmass that would become Europe, Asia, and North America separated from another mass that would split up into other continents. In time, Antarctica and Australia, still joined together, broke away and drifted south. The small piece of land that would become the peninsula of India broke away and for millions of years moved north as a large island. It eventually collided with Asia. Gradually, the different landmasses moved to their present locations.

    The positions of the continents are always changing. North America and Europe are moving away from each other at the rate of about 2.5 centimeters (one inch) per year. If you could visit the planet in the future, you might find that part of the United States's state of California had separated from North America and become an island. Africa might have split in two along the Great Rift Valley. It is even possible that another supercontinent may form someday.

    Continental Features

    The surface of the continents has changed many times because of mountain building, weathering, erosion, and build-up of sediment. Continuous, slow movement of tectonic plates also changes surface features.

    The rocks that form the continents have been shaped and reshaped many times. Great mountain ranges have risen and then have been worn away. Ocean waters have flooded huge areas and then gradually dried up. Massive ice sheets have come and gone, sculpting the landscape in the process.

    Today, all continents have great mountain ranges, vast plains, extensive plateaus, and complex river systems. The landmasses&rsquos average elevation above sea level is about 838 meters (2,750 feet).

    Although each is unique, all the continents share two basic features: old, geologically stable regions, and younger, somewhat more active regions. In the younger regions, the process of mountain building has happened recently and often continues to happen.

    The power for mountain building, or orogeny, comes from plate tectonics. One way mountains form is through the collision of two tectonic plates. The impact creates wrinkles in the crust, just as a rug wrinkles when you push against one end of it. Such a collision created Asia&rsquos Himalayas several million years ago. The plate carrying India slowly and forcefully shoved the landmass of India into Asia, which was riding on another plate. The collision continues today, causing the Himalayas to grow taller every year.

    Recently formed mountains, called coastal ranges, rise near the western coasts of North America and South America. Older, more stable mountain ranges are found in the interior of continents. The Appalachians of North America and the Urals, on the border between Europe and Asia, are older mountain ranges that are not geologically active.

    Even older than these ancient, eroded mountain ranges are flatter, more stable areas of the continents called cratons. A craton is an area of ancient crust that formed during Earth&rsquos early history. Every continent has a craton. Microcontinents, like New Zealand, lack cratons.

    Cratons have two forms: shields and platforms. Shields are bare rocks that may be the roots or cores of ancient mountain ranges that have completely eroded away. Platforms are cratons with sediment and sedimentary rock lying on top.

    The Canadian Shield makes up about a quarter of North America. For hundreds of thousands of years, sheets of ice up to 3.2 kilometers (two miles) thick coated the Canadian Shield. The moving ice wore away material on top of ancient rock layers, exposing some of the oldest formations on Earth. When you stand on the oldest part of the Canadian Shield, you stand directly on rocks that formed more than 3.5 billion years ago.

    North America

    North America, the third-largest continent, extends from the tiny Aleutian Islands in the northwest to the Isthmus of Panama in the south. The continent includes the enormous island of Greenland in the northeast. In the far north, the continent stretches halfway around the world, from Greenland to the Aleutians. But at Panama&rsquos narrowest part, the continent is just 50 kilometers (31 miles) across.

    Young mountains&mdashincluding the Rockies, North America&rsquos largest chain&mdashrise in the West. Some of Earth&rsquos youngest mountains are found in the Cascade Range of the U.S. states of Washington, Oregon, and California. Some peaks there began to form only about a million years ago&mdasha wink of an eye in Earth&rsquos long history. North America&rsquos older mountain ranges rise near the East Coast of the United States and Canada.

    In between the mountain systems lie wide plains that contain deep, rich soil. Much of the soil was formed from material deposited during the most recent glacial period. This Ice Age reached its peak about 18,000 years ago. As glaciers retreated, streams of melted ice dropped sediment on the land, building layers of fertile soil in the plains region. Grain grown in this region, called the &ldquobreadbasket of North America,&rdquo feeds a large part of the world.

    North America contains a variety of natural wonders. Landforms and all types of vegetation can be found within its boundaries. North America has deep canyons, such as Copper Canyon in the Mexican state of Chihuahua. Yellowstone National Park, in the U.S. state of Wyoming, has some of the world&rsquos most active geysers. Canada&rsquos Bay of Fundy has the greatest variation of tide levels in the world. The Great Lakes form the planet&rsquos largest area of freshwater. In California, giant sequoias, the world&rsquos most massive trees, grow more than 76 meters (250 feet) tall and nearly 31 meters (100 feet) around.

    Greenland, off the east coast of Canada, is the world&rsquos largest island. Despite its name, Greenland is mostly covered with ice. Its ice is a remnant of the great ice sheets that once blanketed much of the North American continent. Greenland is the only place besides Antarctica that still has an ice sheet.

    From the freezing Arctic to the tropical jungles of Central America, North America enjoys more climate variation than any other continent. Almost every type of ecosystem is represented somewhere on the continent, from coral reefs in the Caribbean to Greenland&rsquos ice sheet to the Great Plains in the U.S. and Canada.

    Today, North America is home to the citizens of Canada, the United States, Greenland, Mexico, Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, and the island countries and territories that dot the Caribbean Sea and the western North Atlantic.

    Most of North America sits on the North American Plate. Parts of the Canadian province of British Columbia and the U.S. states of Washington, Oregon, and California sit on the tiny Juan de Fuca Plate. Parts of California and the Mexican state of Baja California sit on the enormous Pacific Plate. Parts of Baja California and the Mexican states of Baja California Sur, Sonora, Sinaloa, and Jalisco sit on the Cocos Plate. The Caribbean Plate carries most of the small islands of the Caribbean Sea (south of the island of Cuba) as well as Central America from Honduras to Panama. The Hawaiian Islands, in the middle of the Pacific Ocean on the Pacific Plate, are usually considered part of North America.

    South America

    South America is connected to North America by the narrow Isthmus of Panama. These two continents weren&rsquot always connected they came together only three million years ago. South America is the fourth-largest continent and extends from the sunny beaches of the Caribbean Sea to the frigid waters near the Antarctic Circle.

    South America&rsquos southernmost islands, called Tierra del Fuego, are less than 1,120 kilometers (700 miles) from Antarctica. These islands even host some Antarctic birds, such as penguins, albatrosses, and terns. Early Spanish explorers visiting the islands for the first time saw small fires dotting the land. These fires, made by indigenous people, seemed to float on the water, which is probably how the islands got their name&mdashTierra del Fuego means "Land of Fire."

    The Andes, Earth&rsquos longest terrestrial mountain range, stretch the entire length of South America. Many active volcanoes dot the range. These volcanic areas are fueled by heat generated as a large oceanic plate, called the Nazca Plate, grinds beneath the plate carrying South America.

    The central-southern area of South America has pampas, or plains. These rich areas are ideal for agriculture. The growing of wheat is a major industry in the pampas. Grazing animals, such as cattle and sheep, are also raised in the pampas region.

    In northern South America, the Amazon River and its tributaries flow through the world&rsquos largest tropical rainforest. In volume, the Amazon is the largest river in the world. More water flows from it than from the next six largest rivers combined.

    South America is also home to the world&rsquos highest waterfall, Angel Falls, in the country of Venezuela. Water flows more than 979 meters (3,212 feet)&mdashalmost a mile. The falls are so high that most of the water evaporates into mist or is blown away by wind before it reaches the ground.

    South American rainforests contain an enormous wealth of animal and plant life. More than 15,000 species of plants and animals are found only in the Amazon River basin. Many Amazonian plant species are sources of food and medicine for the rest of the world. Scientists are trying to find ways to preserve this precious and fragile environment as people move into the Amazon basin and clear land for settlements and agriculture.

    Twelve independent countries make up South America: Brazil, Colombia, Argentina, Peru, Venezuela, Chile, Ecuador, Bolivia, Paraguay, Uruguay, Guyana, and Suriname. The territories of French Guiana, part of France, and the Falkland Islands, part of the United Kingdom, are also part of South America.

    Almost all of South America sits on top of the South American Plate.

    Europe, the sixth-largest continent, contains just seven percent of the world&rsquos land. In total area, the continent of Europe is only slightly larger than the country of Canada. However, the population of Europe is more than twice that of South America. Europe has more than 40 countries and many of the world&rsquos major cities, including London, the United Kingdom Paris, France Berlin, Germany Rome, Italy Madrid, Spain and Moscow, Russia.

    Most European countries have access to the ocean. The continent is bordered by the Arctic Ocean in the north, the Atlantic Ocean in the west, the Caspian Sea in the southeast, and the Mediterranean and Black Seas in the south. The nearness of these bodies of water and the navigation of many of Europe&rsquos rivers played a major role in the continent&rsquos history. Early Europeans learned the river systems of the Volga, Danube, Don, Rhine, and Po, and could successfully travel the length and width of the small continent for trade, communication, or conquest.

    Navigation and exploration outside of Europe was an important part of the development of the continent&rsquos economic, social, linguistic, and political legacy. European explorers were responsible for colonizing land on every continent except Antarctica. This colonization process had a drastic impact on the economic and political development of those continents, as well as Europe.

    In the east, the Ural Mountains separate Europe from Asia. The nations of Russia and Kazakhstan straddle both continents. Another range, the Kjølen Mountains, extends along the northern part of the border between Sweden and Norway. To the south, the Alps form an arc stretching from Albania to Austria, then across Switzerland and northern Italy into France. As the youngest and steepest of Europe&rsquos mountains, the Alps geologically resemble the Rockies of North America, another young range.

    A large area of gently rolling plains extends from northern France eastward to the Urals. A climate of warm summers, cold winters, and plentiful rain helps make much of this European farmland very productive.

    The climate of Western Europe, especially around the Mediterranean Sea, makes it one of the world&rsquos leading tourism destinations.

    Almost all of Europe sits on the massive Eurasian Plate.

    Africa, the second-largest continent, covers an area more than three times that of the United States. From north to south, Africa stretches about 8,000 kilometers (5,000 miles). It is connected to Asia by the Isthmus of Suez in Egypt.

    The Sahara, which covers much of North Africa, is the world&rsquos largest hot desert. The world&rsquos longest river, the Nile, flows more than 6,560 kilometers (4,100 miles) from its most remote headwaters in Lake Victoria to the Mediterranean Sea in the north. A series of falls and rapids along the southern part of the river makes navigation difficult. The Nile has played an important role in the history of Africa. In ancient Egyptian civilization, it was a source of life for food, water, and transportation.

    The top half of Africa is mostly dry, hot desert. The middle area has savannas, or flat, grassy plains. This region is home to wild animals such as lions, giraffes, elephants, hyenas, cheetahs, and wildebeests. The central and southern areas of Africa are dominated by rainforests. Many of these forests thrive around Africa&rsquos other great rivers, the Zambezi, the Congo, and the Niger. However, trees are being cut down in Africa&rsquos rainforests for many of the same reasons deforestation is taking place in the rainforests of South America and Asia: development for businesses, homes, and agriculture.

    Much of Africa is a high plateau surrounded by narrow strips of coastal lowlands. Hilly uplands and mountains rise in some areas of the interior. Glaciers on Mount Kilimanjaro in Tanzania sit just kilometers from the tropical jungles below. Even though Kilimanjaro is not far from the Equator, snow covers its summit all year long.

    In eastern Africa, a giant depression called the Great Rift Valley runs from the Red Sea to the country of Mozambique. (The rift valley actually starts in southwestern Asia.) The Great Rift Valley is a site of major tectonic activity, where the continent of Africa is splitting into two. Geologists have already named the two parts of the African Plate. The Nubian Plate will carry most of the continent, to the west of the rift the Somali Plate will carry the far eastern part of the continent, including the so-called &ldquoHorn of Africa.&rdquo The Horn of Africa is a peninsula that resembles the upturned horn of a rhinoceros. The countries of Eritrea, Ethiopia, Djibouti, and Somalia sit on the Horn of Africa and the Somali Plate.

    Africa is home to 56 countries but only 14 percent of the world&rsquos total population. The area of central-eastern Africa is important to scientists who study evolution and the earliest origins of humanity. This area is thought to be the place where hominids began to evolve.

    The entire continent of Africa sits on the African Plate.

    Asia, the largest continent, stretches from the eastern Mediterranean Sea to the western Pacific Ocean. There are more than 40 countries in Asia. Some are among the most-populated countries in the world, including China, India, and Indonesia. Sixty percent of Earth&rsquos population lives in Asia. More than a third of the world&rsquos people live in China and India alone.

    The continent of Asia includes many islands, some of them countries. The Philippines, Indonesia, Japan, and Taiwan are major island nations in Asia.

    Most of Asia&rsquos people live in cities or fertile farming areas near river valleys, plains, and coasts. The plateaus in Central Asia are largely unsuitable for farming and are thinly populated.

    Asia accounts for almost a third of the world&rsquos land. The continent has a wide range of climate regions, from polar in the Siberian Arctic to tropical in equatorial Indonesia. Parts of Central Asia, including the Gobi Desert in China and Mongolia, are dry year-round. Southeast Asia, on the other hand, depends on the annual monsoons, which bring rain and make agriculture possible.

    Monsoon rains and snowmelt feed Asian rivers such as the Ganges, the Yellow, the Mekong, the Indus, and the Yangtze. The rich valley between the Tigris and Euphrates rivers in western Asia is called the &ldquoFertile Crescent&rdquo for its place in the development of agriculture and human civilization.

    Asia is the most mountainous of all the continents. More than 50 of the highest peaks in the world are in Asia. Mount Everest, which reaches more than 8,700 meters (29,000 feet) high in the Himalaya range, is the highest point on Earth. These mountains have become major destination spots for adventurous travelers.

    Plate tectonics continuously push the mountains higher. As the landmass of India pushes northward into the landmass of Eurasia, parts of the Himalayas rise at a rate of about 2.5 centimeters (one inch) every five years.

    Asia contains, not only, Earth&rsquos highest elevation, but also its lowest place on land: the shores of the Dead Sea in the countries of Israel and Jordan. The land there lies more than 390 meters (1,300 feet) below sea level.

    Although the Eurasian Plate carries most of Asia, it is not the only one supporting major parts of the large continent. The Arabian Peninsula, in the continent&rsquos southwest, is carried by the Arabian Plate. The Indian Plate supports the Indian peninsula, sometimes called the Indian subcontinent. The Australian Plate carries some islands in Indonesia. The North American Plate carries eastern Siberia and the northern islands of Japan.

    In addition to being the smallest continent, Australia is the flattest and the second-driest, after Antarctica. The continent is sometimes called Oceania, to include the thousands of tiny islands of the Central Pacific and South Pacific, most notably Melanesia, Micronesia, and Polynesia (including the U.S. state of Hawai'i). However, the continent of Australia itself includes only the nation of Australia, the eastern portion of the island of New Guinea (the nation of Papua New Guinea) and the island nation of New Zealand.

    Australia covers just less than 8.5 million square kilometers (about 3.5 million square miles). Its population is about 31 million. It is the most sparsely populated continent, after Antarctica.

    A plateau in the middle of mainland Australia makes up most of the continent&rsquos total area. Rainfall is light on the plateau, and not many people have settled there. The Great Dividing Range, a long mountain range, rises near the east coast and extends from the northern part of the territory of Queensland through the territories of New South Wales and Victoria. Mainland Australia is known for the Outback, a desert area in the interior. This area is so dry, hot, and barren that few people live there.

    In addition to the hot plateaus and deserts in mainland Australia, the continent also features lush equatorial rainforests on the island of New Guinea, tropical beaches, and high mountain peaks and glaciers in New Zealand.

    Most of Australia&rsquos people live in cities along the southern and eastern coasts of the mainland. Major cities include Perth, Sydney, Brisbane, Melbourne, and Adelaide.

    Biologists who study animals consider Australia a living laboratory. When the continent began to break away from Antarctica more than 60 million years ago, it carried a cargo of animals with it. Isolated from life on other continents, the animals developed into creatures unique to Australia, such as the koala, the platypus, and the Tasmanian devil.

    The Great Barrier Reef, off mainland Australia&rsquos northeast coast, is another living laboratory. The world&rsquos largest coral reef ecosystem, it is home to thousands of species of fish, sponges, marine mammals, corals, and crustaceans. The reef itself is 1,920 kilometers (1,200 miles) of living coral communities. By some estimates, it is the world&rsquos largest living organism.

    Most of Australia sits on the Australian Plate. The southern part of the South Island of New Zealand sits on the Pacific Plate.

    Antarctica is the windiest, driest, and iciest place on Earth. Antarctica is larger than Europe or Australia, but unlike those continents, it has no permanent human population. People who work there are scientific researchers and support staff, such as pilots and cooks.

    The climate of Antarctica makes it impossible to support agriculture or a permanent civilization. Temperatures in Antarctica, much lower than Arctic temperatures, plunge lower than -73 degrees Celsius (-100 degrees Fahrenheit).

    Scientific bases and laboratories have been established in Antarctica for studies in fields that include geology, oceanography, and meteorology. The freezing temperatures of Antarctica make it an excellent place to study the history of Earth&rsquos atmosphere and climate. Ice cores from the massive Antarctic ice sheet have recorded changes in Earth&rsquos temperature and atmospheric gases for thousands of years. Antarctica is also an ideal place for discovering meteorites, or stony objects that have impacted Earth from space. The dark meteorites, often made of metals like iron, stand out from the white landscape of most of the continent.

    Antarctica is almost completely covered with ice, sometimes as thick as 3.2 kilometers (two miles). In winter, Antarctica&rsquos surface area may double as pack ice builds up in the ocean around the continent.

    Like all other continents, Antarctica has volcanic activity. The most active volcano is Mount Erebus, which is less than 1,392 kilometers (870 miles) from the South Pole. Its frequent eruptions are evidenced by hot, molten rock beneath the continent&rsquos icy surface.

    Antarctica does not have any countries. However, scientific groups from different countries inhabit the research stations. A multinational treaty negotiated in 1959 and reviewed in 1991 states that research in Antarctica can only be used for peaceful purposes. McMurdo Station, the largest community in Antarctica, is operated by the United States. Vostok Station, where the coldest temperature on Earth was recorded, is operated by Russia.

    All of Antarctica sits on the Antarctic Plate.

    In addition to the seven major continents, Earth is home to microcontinents, or pieces of land that are not geologically identified with a continent. Major microcontinents include:

    • Zealandia, in the South Pacific Ocean, whose land includes New Zealand and New Caledonia
    • Madagascar, in the South Indian Ocean
    • the Mascarene Plateau, in the South Indian Ocean, whose lands include the Seychelles and Reunion islands
    • the Kerguelen Plateau, in the South Indian Ocean, whose lands include the Kerguelen Islands, a territory of France
    • Jan Mayen, in the North Atlantic Ocean, a Norwegian island

    the art and science of cultivating land for growing crops (farming) or raising livestock (ranching).

    Yes, The South Really Is Different — And It’s Because Of Race

    The debt ceiling crisis may be over (at least until February), but the crisis created by the Republican Party&rsquos sharp reactionary turn emphatically is not. I&rsquove argued that the Tea Party, is the legacy of structural racism in the South dating back to the 1930s, and will remain a powerful force in the Republican Party absent tectonic shocks to the political landscape on the level of the civil rights movement.

    This analysis can and should be pushed further. The South is best understood as an exceptional region inside the United States, with a unique political and cultural milieu birthed by the intersection of slavery and deep religiosity. Southern influence on the rest of the United States has been immense, but the South nonetheless has always been different, marked by the racial caste system that defined its existence until the Civil War. It remains different today.

    Race And Religion

    The buried story of Wednesday&rsquos government-opening vote in the House was a split between Republican Southerners &mdash and everyone else. Southern Republican whites voted overwhelmingly against the deal &mdash󈐱 against, 18 in favor. Other Republicans were evenly split (69 in favor, 71 against) and Democrats, of course, unanimously supported the deal. Roughly the same thing happened the last time House Republicans almost took the United States off the default cliff.

    The overwhelming Tea Party conservatism in the Southern delegation reflects the region&rsquos exceptionally conservative bent. In a brand-new American Politics Research article, Columbia University&rsquos Steven White ran a series of regressions analyses aimed at separating out the effect of region and religion on Southern political views. White found &ldquovery substantial support&rdquo for the idea that Southern whites were across-the-board more conservative than whites in the rest of the country. Moreover, whites in the Deep South (Alabama, Georgia, Louisiana, Mississippi, and South Carolina) were more reactionary than their also super-conservative peers in the Peripheral South (Arkansas, Florida, North Carolina, Tennessee, Texas, and Virginia).

    Southern political uniqueness appeared to be partly religious &mdash but only partly. Roughly half of America&rsquos evangelicals live in the South, a pattern dating back to the early 1800s. Though early Southerners were largely Anglican, evangelical missionaries began flocking to the region in the late 18th century. They found it fertile ground: historian David Edward Harrell Jr. writes that &ldquoby 1830 the &lsquoSolid South&rsquo was more of a religious than a political reality.&rdquo Since then, Southern Oregon University&rsquos Mark Shibley documents, evangelical faith has dominated spiritual and cultural life among Southern whites in a way that it hasn&rsquot anywhere else in the United States.

    White&rsquos research suggests this preponderance of fundamentalism explains the region&rsquos socially conservative bent. It also somewhat accounts for the South&rsquos heavy Republican tilt in Presidential elections, but only partially and in certain Southern states. And it does virtually no lifting on region&rsquos broader conservatism on issues like the Iraq War and attitudes towards Muslims. Something else, something distinctly regional, explains why the South, both Deep and Peripheral, has more conservative views across-the-board than the rest of the country.

    Race, and its historical legacy, appears to be the key. While early America was no doubt shot through with racism everywhere, slavery set the South apart. Slavery, and the attendant distinctions between black and white created to provide its intellectual underpinnings, formed the very core of the Southern political, economic, and social system. The idea that a system so important that the South went to war rather than compromise over it would not play an extraordinary role in shaping the region&rsquos politics is absurd.

    Demonstrably absurd, in fact. Three political scientists at the University of Rochester found that, when you control for series of potentially confounding factors, white Southerners in the Mississippi Delta-to-Georgia &ldquoBlack Belt&rdquo were &ldquoless likely to identify as Democrat, more likely to oppose affirmative action policies, and more likely to express racial resentment toward blacks&rdquo if their county housed high percentages of slaves prior to the Civil War. This effect survives controls for the percentage of African Americans in-county today, inclining the Rochester scholars to believe that racial prejudice (in mutating forms, to be sure) has been passed down continually among Deep South whites from parent-to-child since slavery.

    This jives with other recent research on the broader South, which finds that &ldquowhites residing in the old Confederacy continue to display more racial antagonism and ideological conservatism than non-Southern whites.&rdquo Moreover, &ldquoracial conservatism has become linked more closely to presidential voting and party identification over time in the white South, while its impact has remained constant elsewhere.&rdquo

    Race and religion, then, have always set the South apart. So the South&rsquos turn away from the Democratic Party over race, beginning in the 1930s and finalizing in the 1990s, is a pattern of evolution consistent with the region&rsquos long history of racial conservatism. That the religious right became a dominant force in both the South and the Republican party in the 80s and 90s is the other side of the coin. Evangelical conservative hostility towards government interference with religious schools and &ldquotraditional&rdquo cultural norms relating to gender and sexual orientation meld quite well with the fiscal conservative insistence on keeping the state out of private economic affairs and civil society &mdash a cause that segregationists took up after the civil rights movement&rsquos victory to defend de facto segregation using race-neutral language.

    The South, in short, was a region uniquely well suited for the modern conservative movement&rsquos &ldquofusion&rdquo between social and economic conservatism. It&rsquos no surprise that the South is the driver of hard-right conservatism today. That&rsquos what its racial and religious heritage would suggest.

    The Not-So-Exceptional South?

    Not everyone agrees. In a fantastic essay in Jacobin, Seth Ackerman presents an alternate history of the growth of the Tea Party in which the South plays no special role. His target is not merely folks like John Judis and myself who emphasize the South&rsquos role in modern conservatism, but the idea of Southern exceptionalism itself.

    The Southern bolt from the Democratic Party was not principally about uniquely Southern race issues, Ackerman argues, but rather an outgrowth of the South&rsquos economic catchup with the North. As Southern whites became more affluent, they became more open to free-market policies. After affluence opened the crack, religion pushed the South over the edge: the South today votes more conservatively because of its highly religious white population.

    And The Tea Party, Ackerman concludes, isn&rsquot particularly Southern. Instead, it&rsquos born of the American &ldquoreactionary national consensus over a backward set of fundamental governing structures.&rdquo Because the Constitution has foiled any attempt to legislate effectively, he suggests, Americans have developed a deep skepticism about the idea of legislating itself. The Tea Party is merely the latest manifestation of this skepticism.

    Ackerman&rsquos essay is a valuable corrective to some of the more reductionist tendencies in the sort of explanation I&rsquom partial towards. In particular, he is right to say that the South slid towards GOP and broad-based conservatism gradually from the 1930s forward, rather than in isolated bursts in 1964 and 1980. He&rsquos also right that the Tea Party isn&rsquot solely made up of Southerners and that Southern political behavior can&rsquot be understood in isolation from Southern religiosity.

    But he&rsquos quite wrong on the main issue. The South&rsquos shift to the Republican Party really was principally about the region&rsquos unique racial heritage &mdash a history that Southern religion cannot escape from.

    Let&rsquos look at some of Ackerman&rsquos particular arguments. First, he cites research by Byron Shafer and Richard Johnston to support the idea that &ldquowhite-collar, affluent, and suburban districts &mdash i.e. those that were the most &ldquomodern&rdquo, &ldquoAmerican,&rdquo and populated with northern transplants &mdash that led the way toward GOP dominance, while those that were most traditionally &lsquoSouthern&rsquo lagged behind.&rdquo It couldn&rsquot be race that pushed the South Republican, in other words, if its most racially progressive areas led the move towards the Republican Party.

    Subsequent reviews, however, have found fatal flaws in the Shafer and Johnston thesis. CalTech&rsquos J. Morgan Kousser writes that Shafer and Johnston &ldquofundamentally rested their case on a simple chronological argument: The Republican Party became solidly established first in the areas with few African-Americans,&rdquo failing to take a more serious look at the data correlating the politics of race with the rise of the Republican South. A more detailed look found that &ldquosubstantial economic development in the Rim South (the more-white states) preceded the development of vigorous state level Republican parties, which emerged only with the passage of national civil rights legislation.&rdquo Moreover, &ldquothe timing of the onset of serious state-level Republican campaigns coincided not with the long, slow, ongoing development of the economy, but with the commitment of the Democratic Party nationally to a civil rights agenda.&rdquo

    This pattern can be seen on a state-to-state level. M. V. Hood, III, Quentin Kidd, and Irwin L. Morris find that &ldquothe Southern states with the largest per capita income growth from 1960 to 1980 were (in order) Virginia, Florida, and Texas,&rdquo while &ldquothe states with the largest GOP growth during the time period were (in order) Mississippi, South Carolina, and Georgia.&rdquo The state where the GOP grew the fastest &mdash Mississippi &mdash was the one with the slowest economic regional economic growth during the critical Southern transition period, leading the authors to conclude &ldquoat the most basic level, there are obvious problems with a class-based explanation.&rdquo Hood, Kidd, and Morris proceed to put together strong statistical evidence that race, not &ldquonormal&rdquo class politics, explained the Southern shift towards Republicans.

    Second, he cites research suggesting Southern Democrats were as or more left-wing on economic issues as Northerners up until roughly the end of the New Deal. This bafflingly leads him to conclude that &ldquothe closest modern-day equivalents of the conservative Democrats of the 1940s are modern-day conservative Democrats.&rdquo Today&rsquos Southern Democrats are, if anything, the opposite of Dixiecrats: they&rsquore more conservative on economics than their Northern peers today and far more progressive on race than their regional peers in the 1930s.

    It&rsquos also not very helpful to attempt to map political views one-to-one from one historical time period to the next, and no proponent of the race theory depends the Dixiecrat-to-Tea-Party line on such a mapping. Instead, the argument is that the same underlying structural trends in Southern political opinion produced both the Dixiecrats and hard-right Southern Republicans &mdash sometimes in the same person (see Thurmond, Strom). If I&rsquom right, and racial conservatism pulled Southern whites towards economic conservatism, then the thread tying the Dixiecrats to the Tea Party is that structural racism caused the same population to transition from the former to the latter.

    Segregation And The Religious Right

    But what about religion &mdash they other key cause of Southern exceptionalism?

    Ackerman suggests Southern religiosity explains its propensity to vote conservatively in presidential elections, but this simple correlation between whites saying religion is &ldquovery important&rdquo in their lives and conservative voting does not sustain a more detailed regional analysis. According to White&rsquos data, Republican dominance in Texas and the Deep South &mdash the heart of the modern Republican Party &mdash cannot be explained by the prevalence of born-again Christianity alone.

    Historically, Ackerman&rsquos theory is also quite puzzling. In the 30s and 40s, when by Ackerman&rsquos own account Southern politicians were to the nation&rsquos economic left, &ldquoevangelicalism was&hellippart of the very fabric of Southern life,&rdquo as Shibley puts it. &ldquoExplaining just how evangelicalism among Southern whites has driven the surge in Southern Republicanism is difficult,&rdquo Hood et al. write, &ldquoand the empirical connection between evangelicalism and the growth of Republicanism at either the regional level or the subregional level, remain unestablished.&rdquo

    That&rsquos because the Religious Right, the movement that took Southern evangelicalism from a quietistic cultural force and made it into a political juggernaut, didn&rsquot take shape until the late 70s &mdash well after the growth of the GOP in the South was underway. But even then, the Religious Right&rsquos growth was tied up in the South&rsquos race problem.

    White evangelicals played a mixed role during the Civil Rights movement. Church leadership was generally indifferent or hostile, but some lower-level faith organizations helped break down racial barriers. In the late 60s and 70s, however, conservative operatives came to realize evangelicals&rsquo enormous untapped political power. According to Paul Weyrich, easily one of the most important figures in the Religious Right&rsquos founding, nothing could mobilize religious voters for the right (they voted for Jimmy Carter in huge numbers in 1976) until the federal government came after segregated schools.

    That&rsquos right. &ldquoIt was not the school-prayer issue, and it was not the abortion issue,&rdquo Weyrich said. &ldquoWhat caused the movement to surface,&rdquo he told Columbia University&rsquos Randall Balmer, &ldquowas the federal government&rsquos move against the Christian schools.&rdquo After Brown v. Board of Education, many Southern whites moved their kids to private schools (&ldquosegregation academies,&rdquo in common parlance). Many of these academies were religious in character.

    Though segregated private schools were most common at the pre-college level, Bob Jones University, which was fully segregated until 1971 and subsequently continued to ban interracial dating, become the flashpoint. In in 1970, the Internal Revenue Service began proceedings against BJU and, in 1975, the IRS revoked its tax-exempt status, citing its racially discriminatory practices. Weyrich and his allies spun IRS&rsquo action into a liberal campaign against the Christian way of life. The Religious Right as an organized movement grew in significant part out of the defense of Bob Jones and other similarly &ldquopersecuted&rdquo Christian schools.

    This history is fairly well-established. Ed Dobson, one of Jerry Fallwell&rsquos top aides, confirmed it to Balmer: &ldquogovernment interference in Christian schools,&rdquo he said, was one of the core original causes of the original religious right. Balmer, rightly acknowledging that the defense of Bob Jones was motivated by a perceived federal threat to Christian institutions rather than racism, nevertheless notes its history can&rsquot be understood absent race:

    The evangelical defense of Bob Jones University and its racially discriminatory policies may not have been motivated primarily by racism. Still, it&rsquos fair to point out the paradox that the very people who styled themselves the &ldquonew abolitionists&rdquo to emphasize their moral kinship with the nineteenth-century opponents of slavery actually coalesced as a political movement, effectively, to defend racial discrimination.

    The point of all this is that is that Southern evangelical faith is not &ldquonaturally&rdquo a conservative political force in the way that Ackerman implies. Evangelical Christianity was politicized by conservative activists who exploited the legacy of Jim Crow to mobilize evangelicals as foot soldiers in the emerging Republican and conservative Southern establishment that itself was born from segregation&rsquos ashes. It isn&rsquot religion that explains the South&rsquos conservatism it was the rise of conservatism that explains the powerful political role Southern religion plays today.

    Southern Exceptionalism Forever?

    Ackerman&rsquos other arguments similarly do not persuade. Yes, the Tea Party isn&rsquot exclusively Southern &mdash but that&rsquos explained by the nationalization of Southern conservatism. Yes, the Constitution likely plays some role in making Americans more hostile towards government than citizens of other liberal democracies, but that does not explain why the South is so much more conservative than the rest of the nation. Americans in New York, after all, are governed by the same U.S. Constitution as Americans in South Carolina.

    But I&rsquod like to highlight one other thing I think Ackerman gets right. He diagnoses the debate over Southern exceptionalism as a proxy for an older and deeper one between progressives and folks to their left. Progressives tend to think that America&rsquos broadly liberal ideology &mdash individual rights, democracy, the whole kit and kaboodle &mdash is fundamentally opposed to a more sinister ideology that also shaped our founding &mdash the black/white racism that sustained slavery. More radical leftists, especially those of a Marxist bent like Ackerman, disagree, believing that emphasizing racial exceptionalism obscures the ways in which the broader structure of American society makes the country&rsquos political institutions intrinsically unfair and unequal.

    Allow me to side with the first camp. We&rsquove made significant progress beating back discrimination, to the point where naked racism is politically unacceptable even in the Deep South. Movements suffused with liberal ideals about freedom and individual rights played a huge role in these victories.

    This progress seems primed to continue, as younger Americans, including younger whites, are both significantly more tolerant and significantly more leftist than their older peers. Demographic change will hasten this trend &mdash even in the South. Virginia voted for Obama twice, after all, and North Carolina did so once &mdash the first time a Democrat had won either state since Jimmy Carter mobilized the evangelical vote in 1976.

    Studies of Tea Party attitudes suggest a pervasive fear that America is no longer &ldquotheir&rdquo country. Sociologist Theda Skocpol, one of the foremost scholars of the political movement, sees a tinge of racism and xenophobia in that, but more importantly &ldquothey also resent young people &mdash including in their own families.&rdquo

    They believe, according to Skocpol, that younger folks &ldquohold ideas that are not very American.&rdquo In reality, these younger folks hold ideas that are not very traditionally Southern. That&rsquos a hopefully sign that the South&rsquos past does not need to be its future.

    Opportunities in Geography

    The following information on careers in geography is from the website of the Association of American Geographers (AAG), which is a resource for those interested in pursuing employment in the field of geography (http://www.aag.org).

    Many occupations require knowledge of and skills in geography. Geographers work in many different areas, such as environmental management, education, disaster response, city and county planning, community development, and more. Geography is an interdisciplinary field that offers diverse career opportunities.

    Many geographers pursue rewarding careers in business local, state, or federal government agencies nonprofit organizations and schools. Geographers with graduate (master’s and doctorate) degrees may become educators in higher education (community colleges and universities).

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