Statistical evaluation of alternative models of human evolution

@article{citeulike:1851180, abstract = {An appropriate model of recent human evolution is not only important to understand our own history, but it is necessary to disentangle the effects of demography and selection on genome diversity. Although most genetic data support the view that our species originated recently in Africa, it is still unclear if it completely replaced former members of the Homo genus, or if some interbreeding occurred during its range expansion. Several scenarios of modern human evolution have been proposed on the basis of molecular and paleontological data, but their likelihood has never been statistically assessed. Using DNA data from 50 nuclear loci sequenced in African, Asian and Native American samples, we show here by extensive simulations that a simple African replacement model with exponential growth has a higher probability (78\%) as compared with alternative multiregional evolution or assimilation scenarios. A Bayesian analysis of the data under this best supported model points to an origin of our species {approx}141 thousand years ago (Kya), an exit out-of-Africa {approx}51 Kya, and a recent colonization of the Americas {approx}10.5 Kya. We also find that the African replacement model explains not only the shallow ancestry of mtDNA or Y-chromosomes but also the occurrence of deep lineages at some autosomal loci, which has been formerly interpreted as a sign of interbreeding with Homo erectus. 10.1073/pnas.0708280104}, author = {Fagundes, Nelson J. and Ray, Nicolas and Beaumont, Mark and Neuenschwander, Samuel and Salzano, Francisco M. and Bonatto, Sandro L. and Excoffier, Laurent }, citeulike-article-id = {1851180}, doi = {http://dx.doi.org/10.1073/pnas.0708280104}, journal = {Proceedings of the National Academy of Sciences}, keywords = {evolution, human}, month = {October}, pages = {0708280104+}, posted-at = {2007-11-11 06:55:35}, priority = {2}, title = {Statistical evaluation of alternative models of human evolution}, url = {http://dx.doi.org/10.1073/pnas.0708280104}, year = {2007} }

TY - JOUR ID - citeulike:1851180 L3 - citeulike-article-id:1851180 TI - Statistical evaluation of alternative models of human evolution JF - Proceedings of the National Academy of Sciences SP - 0708280104 N2 - An appropriate model of recent human evolution is not only important to understand our own history, but it is necessary to disentangle the effects of demography and selection on genome diversity. Although most genetic data support the view that our species originated recently in Africa, it is still unclear if it completely replaced former members of the Homo genus, or if some interbreeding occurred during its range expansion. Several scenarios of modern human evolution have been proposed on the basis of molecular and paleontological data, but their likelihood has never been statistically assessed. Using DNA data from 50 nuclear loci sequenced in African, Asian and Native American samples, we show here by extensive simulations that a simple African replacement model with exponential growth has a higher probability (78%) as compared with alternative multiregional evolution or assimilation scenarios. A Bayesian analysis of the data under this best supported model points to an origin of our species {approx}141 thousand years ago (Kya), an exit out-of-Africa {approx}51 Kya, and a recent colonization of the Americas {approx}10.5 Kya. We also find that the African replacement model explains not only the shallow ancestry of mtDNA or Y-chromosomes but also the occurrence of deep lineages at some autosomal loci, which has been formerly interpreted as a sign of interbreeding with Homo erectus. 10.1073/pnas.0708280104 KW - evolution KW - human AU - Fagundes, Nelson AU - Ray, Nicolas AU - Beaumont, Mark AU - Neuenschwander, Samuel AU - Salzano, Francisco AU - Bonatto, Sandro AU - Excoffier, Laurent PY - 2007/10/31/ UR - http://dx.doi.org/10.1073/pnas.0708280104 ER -