Out of Africa

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Out of Africa is about the recent African origin of modern humans. Since the 1980s this has been supported by a study of present-day mitochondrial DNA, and other sequence analysis. There is also evidence based on the physical anthropology of archaic fossil remains. The idea is very well supported.[1][2][3][4][5] There are differing theories on whether there was a single exodus or several. A growing number of researchers also suspect that "long-neglected North Africa" was the original home of the modern humans who first trekked out of the continent.[6][7][8]

The first truly modern humans seem to have appeared between 200,000 and 130,000 years ago.[9][10] These early humans later moved out from Africa. By about 90,000 years ago they had moved into Eurasia and the Middle East. This was the area where earlier species of humans, (such as Neanderthals, Homo neanderthalensis) had been living for a long time (at least 500,000 years in western Europe).

By about 42 to 44,000 years ago Homo sapiens had reached western Europe, including Britain.[11] In Europe and western Asia, Homo sapiens replaced the Neanderthals by about 35,000 years ago. The details of this event are not known. At roughly the same time Homo sapiens arrived in Australia. Their arrival in the Americas was much later, about 15,000 years ago.[12] All these earlier groups of modern man were hunter-gatherers.

Genetic studies and fossil evidence show that archaic Homo sapiens evolved to anatomically modern humans solely in Africa between 200,000 and 60,000 years ago.[13] Members of one branch of Homo sapiens left Africa at some point between 125,000 and 60,000 years ago, and that over time these humans replaced earlier populations of the genus Homo such as Neanderthals and Homo erectus.[14]

The date of the earliest successful "out of Africa" migration (earliest migrants with living descendants) has generally been placed at 60,000 years ago based on genetics, but migration out of the continent may have taken place as early as 125,000 years ago according to Arabian archaeological finds of tools in the region.[15]

References[change | change source]

  1. Liu H. et al (2006). "A geographically explicit genetic model of worldwide human-settlement history". Am. J. Hum. Genet. 79 (2): 230–7. doi:10.1086/505436. PMC 1559480. PMID 16826514. "Currently available genetic and archaeological evidence is supportive of a recent single origin of modern humans in East Africa. However, this is where the consensus on human settlement history ends, and considerable uncertainty clouds any more detailed aspect of human colonization history.".
  2. "This week in Science: Out of Africa revisited". Science 308 (5724): 921. 2005-05-13. doi:10.1126/science.308.5724.921g.
  3. Stringer C. (2003). "Human evolution: out of Ethiopia". Nature 423 (6941): 692–3, 695. doi:10.1038/423692a. PMID 12802315.
  4. Johanson D. "Origins of modern humans: multiregional or out of Africa?". ActionBioscience. American Institute of Biological Sciences. http://www.actionbioscience.org/evolution/johanson.html.
  5. "Modern Humans – Single Origin (Out of Africa) vs Multiregional". http://www.asa3.org/ASA/education/origins/migration.htm.
  6. Balter M (2011). "Was North Africa the launch pad for modern human migrations?". Science 331 (6013): 20–3. doi:10.1126/science.331.6013.20. PMID 21212332.
  7. Cruciani F. et al; Trombetta; Massaia; Destro-Bisol; Sellitto; Scozzari (2011). "A revised root for the human Y chromosomal phylogenetic tree: the origin of patrilineal diversity in Africa". Am. J. Hum. Genet. 88 (6): 814–8. doi:10.1016/j.ajhg.2011.05.002. PMC 3113241. PMID 21601174.
  8. Smith T.M. et al (2007). "Earliest evidence of modern human life history in North African early Homo sapiens". Proc. Natl. Acad. Sci. U.S.A. 104 (15): 6128–33. doi:10.1073/pnas.0700747104. PMC 1828706. PMID 17372199.
  9. Human ancestors hall: Homo Sapiens – URL retrieved October 13, 2006
  10. Alemseged Z; Coppens Y. & Geraads D. (2002). "Hominid cranium from Omo: description and taxonomy of Omo-323-1976-896". Am J Phys Anthropol 117 (2): 103–12. doi:10.1002/ajpa.10032. PMID 11815945.
  11. Amos, Jonathan 2011. BBC Science News
  12. "Fossil feces is earliest evidence of North American humans". http://news.nationalgeographic.com/news/2008/04/080403-first-americans.html.
  13. Reid G.B.R. & Hetherington R. (2010). The climate connection: climate change and modern human evolution. Cambridge, UK: Cambridge University Press. p. 64. ISBN 0-521-14723-9. https://books.google.com/books?id=AAja8FTPF6QC&pg=PA64.
  14. Meredith M. (2011). Born in Africa: the quest for the origins of human life. New York: PublicAffairs. ISBN 1-58648-663-2. https://books.google.com/books?id=WrR9OShae2wC&pg=PT148.
  15. Armitage S.J. et al (2011). "The southern route "out of Africa": evidence for an early expansion of modern humans into Arabia". Science 331 (6016): 453–6. doi:10.1126/science.1199113. PMID 21273486.