quote:Ten years ago, evidence from genetics gave strong support to the “recent African origin” view of the evolution of modern humans, which posits that Homo sapiens arose as a new species in Africa and subsequently spread, leading to the extinction of other archaic human species. Subsequent data from the nuclear genome not only fail to support this model, they do not support any simple model of human demographic history. In this paper, we study a process in which the modern human phenotype originates in Africa and then advances across the world by local demic diffusion, hybridization, and natural selection. While the multiregional model of human origins posits a number of independent single locus selective sweeps, and the “out of Africa” model posits a sweep of a new species, we study the intermediate case of a phenotypic sweep. Numerical simulations of this process replicate many of the seemingly contradictory features of the genetic data, and suggest that as much as 80% of nuclear loci have assimilated genetic material from non-African archaic humans.
Posts: 7082 | From: Fallbrook, CA | Registered: Mar 2004
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quote:I have read the 2005 paper by Eswaren, Harpending, Rogers and the 2002 Nature paper by Templeton and found that both papers rely upon abstruse mathematical arguments to support claims which attempt to counter the now dominant model of a single exodus out of Africa with replacement of (and no significant interbreeding with) existing archaic hominids. The Eswaren et al and Templeton mathematical models rely on several unproven assumptions and are not sufficient in my view to overturn the elegant and convinving Out of Africa with Replacement Theory propounded by Cavalli-Sforza, Cann, Oppenheimer, and others (which is strongly supported by the coherent and voluminous molecular evidence of Y-chrom and mDNA phylogeny data). The rebels (multiregionalists and assimilationists) really need some hard tangible molecular evidence, not just some assumptions and oversimplifications coupled with complex equations concerning how fast a given allele "should have" expanded.
For any given human gene, just look closely at the racial variations in SNP haplotypes shown in the HapMap and Perlegen databases and it is easy to see how various haplotypes have given rise to the current known haplotypes, we simply do not need to invoke admixture by archaic hominids. (Remember keeping things simple, parsimony, Occam's razor etc. --usually is the correct path to scientific truth.)
There is no need to revive the now outmoded strong multiregional hypothesis of Coon and Wolpoff. The weak multiregional model(assimilation models) assume that modern humans would have interbred with archaic humans. I think this is highly unlikely, archaic hominids would have appeared to modern humans as potentially dangerous animals fit for slaughter and a tasty food source(not as attractive mates).
In summary, in my opinion there is of yet no convincing evidence indicating that the ancestors of Eurasians are anyone other than the the small band of modern humans who left northeast Africa about 60,000 to 80,000 years ago.
quote: have read the 2005 paper by Eswaren, Harpending, Rogers and the 2002 Nature paper by Templeton and found that both papers rely upon abstruse mathematical arguments to support claims which attempt to counter the now dominant model of a single exodus out of Africa
We discussed Templetons similar findings a year ago.
I have great respect for all of Templetons work, but as I said then... I don't understand the mathamatical theory/basis upon which he reaches his conclusion, which is actually not based on actual DNA found in archaic hominids and thence in modern humans, but rather on refutation of the null hypothesis, which can still lead to false conclusion if any of the root assumptions upon which the hypothesis is built are wrong.
This means I do not offer any criticism of this view - I simply don't understand it.
The approach utilised appears to be somewhat impenetrable, a strength and a weaknesss.
It's largely averse to criticism, but equally averse to advocacy.
One side says - heres the math, prove us wrong.
The other says - garbage in, garbage out [ie math modeling based on questionable assumptions], and then they ask for the actual DNA as proof, this means male or female lineages which are not traceable back to Africa within the timeframe of the RAO model, and/or hominid [Neanderthal] DNA found in Eurasians or genetic distance studies showing they are closer related to Neanderthal than Africans are.
Their theory could be right, but I think it will not gain headway until and unless it can be demonstrated directly from DNA and not mathamatical modeling.
Posts: 15202 | Registered: Jun 2004
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Pure B.S. Literally thousands of genetics papers have been based on this fact and have reinforced it, with all currently known lineages coalescing to a perioid of time after 150-200 kya when the species of Homo Sapiens (later sub-group Sapiens) arose in Africa 150-200kya.
-------------------- "Oh the sons of Ethiopia; observe with care; the country called Ethiopia is, first, your mother; second, your throne; third, your wife; fourth, your child; fifth, your grave." - Ras Alula Aba Nega. Posts: 1024 | Registered: Jun 2006
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^You bet, no substitute for DNA markers. If there is evidence of non-exclusive origins of modern humans in Africa, then DNA markers should be able to bring this to light. Every paternal and maternal line of contemporary populations ever studied thus far has its antecedent in Africa, pointing to an African origin.
Posts: 1947 | Registered: Sep 2005
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Null hypothesis mathamatical modeling 'attempts' to account for the scanty DNA evidence, but is the explanation pursuasive?
Posts: 15202 | Registered: Jun 2004
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^ Indeed. I don't know if T-rex realizes it, but his source in an attempt to refute a single African origin postulates interbreeding with primitive non-human species already living in Eurasia. Such a hypothesis has been rejected by the latest genetic research, and I don't know about you but I would feel slightly insulted if it was suggested that because of my Eurasian ancestry I have partial ancestry from non-human ancestors! This seems to be a popular trend with those Eurocentrics still desperately trying to deny their African origins and instead want to cling on to primitive Neanderthals when it was their African ancestors who brought modern (advanced) culture to Europe!
Posts: 26267 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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Here are the background of the authors, just ridiculous, no geneticists. TRex, you can only be sure if you're the real son of your father through DNA, your reference is a joke:
aVinayak Eswarana, , bHenry Harpendingb, , and cAlan R. Rogersc, aDepartment of Mechanical Engineering, Indian Institute of Technology, Kanpur, India 208016 bDepartment of Anthropology, University of Utah, 270S 1400E, Salt Lake City, UT 84112, USA cDepartment of Anthropology, University of Utah, 270S 1400E, Salt Lake City, UT 84112, USA Received 30 June 2004; accepted 8 February 2005. Available online 6 May 2005.Posts: 919 | From: AFRICA | Registered: Apr 2007
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Many of these DNA tests are done in the laboratories of either hospitals, anthropological institutions or universities.
Posts: 1947 | Registered: Sep 2005
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My point is genetics is more relevant in tracing the human origins, anthropologist and engineers won't help...
Posts: 919 | From: AFRICA | Registered: Apr 2007
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My point is genetics is more relevant in tracing the human origins, anthropologist and engineers won't help...
Was it specifically stated somewhere that the researchers in question were merely anthropologists or what have you, without educational background in molecular genetics, and more importantly, does their work in question involve miscroscopic analysis of DNA?
Posts: 1947 | Registered: Sep 2005
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quote:Originally posted by AFRICA I: Here are the background of the authors, just ridiculous, no geneticists. TRex, you can only be sure if you're the real son of your father through DNA, your reference is a joke:
aVinayak Eswarana, , bHenry Harpendingb, , and cAlan R. Rogersc, aDepartment of Mechanical Engineering, Indian Institute of Technology, Kanpur, India 208016 bDepartment of Anthropology, University of Utah, 270S 1400E, Salt Lake City, UT 84112, USA cDepartment of Anthropology, University of Utah, 270S 1400E, Salt Lake City, UT 84112, USA Received 30 June 2004; accepted 8 February 2005. Available online 6 May 2005.
Physiical anthropologists do a large part of the genetic studies on human populations particularly those of interest to us-- i.e. genetics of population movements. Take a look at the titles of papers published in the [italics]American Journal of Physical Anthropology[/italics]. Google Scholar for Harpeding and Rogers to se how many papers they have published on these topics.
Posts: 833 | From: Austin, TX | Registered: Jan 2007
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quote:My point is genetics is more relevant in tracing the human origins, anthropologist and engineers won't help...
History can lie or mislead, Anthropology can lie or mislead...Genetics is more accurate...I don't believe the above authors can compare with the like of Sforza and other genetics in the field of Human Genetics...It's impossible...By the way that's my last post, I don't have time to argue about that...it's useless..
Posts: 919 | From: AFRICA | Registered: Apr 2007
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quote:Originally posted by Lord of the Nile: ...And Human Genetics data could be slanted, misinterpreted, or simply "nuanced".
The Lord
Technically true, no science is irrefutable and uncapable of being twisted.
Posts: 1219 | From: North Carolina, USA | Registered: Jul 2004
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^However, there is such a thing as methodologically refuting what is 'specifically' presented.
Posts: 1947 | Registered: Sep 2005
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^ And there is also such a thing as expressing ridiculous views without any valid evidence at all and/or when all valid evidence long had refutes it. (Marc and Lord of Denial)
Posts: 26267 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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