BACKGROUND: A major unanswered question in the evolution of Homo sapiens is when anatomically modern human populations began to expand: was demographic growth associated with the invention of particular technologies or behavioral innovations by hunter-gatherers in the Late Pleistocene, or with the acquisition of farming in the Neolithic? METHODOLOGY/PRINCIPAL FINDINGS: We investigate the timing of human population expansion by performing a multilocus analysis of > or = 20 unlinked autosomal noncoding regions, each consisting of approximately 6 kilobases, resequenced in approximately 184 individuals from 7 human populations. We test the hypothesis that the autosomal polymorphism data fit a simple two-phase growth model, and when the hypothesis is not rejected, we fit parameters of this model to our data using approximate Bayesian computation. CONCLUSIONS/SIGNIFICANCE: The data from the three surveyed non-African populations (French Basque, Chinese Han, and Melanesians) are inconsistent with the simple growth model, presumably because they reflect more complex demographic histories. In contrast, data from all four sub-Saharan African populations fit the two-phase growth model, and a range of onset times and growth rates is inferred for each population. Interestingly, both hunter-gatherers (San and Biaka) and food-producers (Mandenka and Yorubans) best fit models with population growth beginning in the Late Pleistocene. Moreover, our hunter-gatherer populations show a tendency towards slightly older and stronger growth (approximately 41 thousand years ago, approximately 13-fold) than our food-producing populations (approximately 31 thousand years ago, approximately 7-fold). These dates are concurrent with the appearance of the Late Stone Age in Africa, supporting the hypothesis that population growth played a significant role in the evolution of Late Pleistocene human cultures.
Study finds human population expanded during late Stone Age Genetic evidence is revealing that human populations began to expand in size in Africa during the Late Stone Age approximately 40,000 years ago. A research team led by Michael F. Hammer (Arizona Research Laboratory's Division of Biotechnology at the University of Arizona) found that sub-Saharan populations increased in size well before the development of agriculture. This research supports the hypothesis that population growth played a significant role in the evolution of human cultures in the Late Pleistocene. The team's findings are published in the online peer reviewed journal PLoS ONE on July 29. Reconstructions of the timing and magnitude of changes in human population size are important for understanding the evolution of our species. There has been a longstanding disagreement whether humans began to increase in number as a result of innovative technologies and/or behaviors formulated by hunter-gatherer groups in the Late Pleistocene, or with the advent of agriculture in the Neolithic. Hammer's research integrates empirical genetics with discoveries in paleontology and archeology to help provide answers to interdisciplinary questions about which kinds of innovations led to the evolutionary success of humankind. Hammer's UA team, together with their collaborator from the University of California San Francisco's Institute for Human Genetics and Department of Epidemiology and Biostatistics, surveyed the genetic material of ~184 individuals from seven human populations and used a computational approach to simulate the evolution of genetic lineages over time. The researchers found that both hunter-gathers and food-producing groups best fit models with approximately ten-fold population growth beginning well before the origin of agriculture. For the first time ever, Hammer's team was able to investigate the timing of human population expansion by applying sophisticated inferential statistics to a large multilocus autosomal data set re-sequenced in multiple contemporary sub-Saharan African populations. The team's finely executed experimental design and use of supercomputing power enabled them to determine that this expansion in population size likely began at the start of the Late Stone Age—a period in prehistory that shows an intensification of archeological sites, an increased abundance of blade-based lithic technologies, and enhanced long-distance exchange. The next step in the project is to gather more data by testing more populations and additional parts of the genome. More information: Cox MP, Morales DA, Woerner AE, Sozanski J, Wall JD, et al. (2009) Autosomal Resequence Data Reveal Late Stone Age Signals of Population Expansion in Sub-Saharan African Foraging and Farming Populations. PLoS ONE 4(7): e6366. doi:10.1371/journal.pone.0006366 Source: Public Library of Science (news : web)
Posts: 2007 | From: Washington State | Registered: Oct 2006
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quote:Originally posted by Evergreen: Autosomal resequence data reveal Late Stone Age signals of population expansion in sub-Saharan African foraging and farming populations.
The team's finely executed experimental design and use of supercomputing power enabled them to determine that this expansion in population size likely began at the start of the Late Stone Age a period in prehistory that shows an intensification of archeological sites, an increased abundance of blade-based lithic technologies, and enhanced long-distance exchange.
Evergreen Writes: Further proof that the Neolithic of Africa, Western Asia and Europe should be considered a part of a broader series of innovations that begun in the Great Lakes of East Africa then spread to the Nile, Levant SE Europe and on up into Central and Northern Europe, etc.
Posts: 2007 | From: Washington State | Registered: Oct 2006
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posted
Everyone outside of Africa is of African origin. The early people of West Asia by the way, just a few thousand years ago, looked like Africans according to scientific studies.
-------------------- Note: I am not an "Egyptologist" as claimed by some still bitter, defeated, trolls creating fake profiles and posts elsewhere. Hapless losers, you still fail. My output of hard data debunking racist nonsense has actually INCREASED since you began.. Posts: 5905 | From: The Hammer | Registered: Aug 2008
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quote:Originally posted by BrandonP: ^ Are you suggesting that the first farmers in Southwest Asia were of African origin?
Evergreen Writes:
Yes, they were heterogeneous with multiple origins. African was one of them.
Posts: 2007 | From: Washington State | Registered: Oct 2006
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