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→Migration From Africa
==Migration From Africa==
Scientists do not completely agree on all the genetic and archaeological data, but there may have been two main migrations from Africa (Figure 1). The first may have been relatively small and it may have occurred more than 140,000 years ago. This migration could have resulted in population spreading to West and East Asia, as far as Indonesia. However, the second main migration, between 80,000-50,000 years ago, seems to have been far more significant. In fact, nearly 98% of human genetics found in many global populations appear to trace their genetics to this second migration. In effect, this might have meant that the first migration may not have been successful or it resulted in a more limited population in different regions outside of Africa. The second migration, which could have consisted of sub-migration over the span of time, seemed to spread far and more rapidly across the globe. <ref>For more on the main migrations out of Africa, see: Hans-Jürgen Bandelt, Vincent Macaulay, & Martin Richards (eds.) (2006) <i>Human mitochondrial DNA and the evolution of homo sapiens.</i> Nucleic acids and molecular biology 18. Berlin ; New York, Springer, pg. 235.</ref>
Cro-Magnon are generally considered the first anatomically modern humans in Europe at about 50,000 years ago. Already nearly 1 million years ago, the earliest <i>Homo</i> species had migrated to Europe, likely via Eurasia. As modern humans expanded in Europe and Asia, they increasingly came across Neanderthals. At this point, humans were most likely competing with Neanderthals for resources and food. At times, the two species were similar enough to breed, which has resulted in some genetic makeup of modern humans have Neanderthals DNA (some populations range in having 1% to 4% influence in DNA from Neanderthals), but this seems to have been relatively limited. By 20,000 years ago, Neanderthals had disappeared. <ref>For more on migration into Eurasia, see: Semino, O. (2000) The Genetic Legacy of Paleolithic Homo sapiens sapiens in Extant Europeans: A Y Chromosome Perspective. <i>Science</i> [Online] 290 (5494), 1155–1159. Available from: doi:10.1126/science.290.5494.1155.</ref>
In east Asia, east Siberia, Korea, and Japan may have been reached by 35,000 years ago by modern humans. This population that migrated to this region also led to a sub-population that became the first colonizers of the Americas. It is not clear when, but between 40,000-16,500 years ago, modern human migrated over the Beringia land bridge, likely using the ice sheets that formed in the late glacial maximum period when ice sheets and glaciers covered many parts of North America. Recent genetic work has shown that human populations in the Amazon are genetically similar to Australoid populations, or populations that also migrated to east Asia and Australia. In effect, human migrations to the Americas likely traveled along the coastal regions between North and South America.
