TY - JOUR
T1 - The evolution of human populations
T2 - A molecular respective
AU - Ayala, Francisco J.
AU - Escalante, Ananias A.
N1 - Funding Information:
We are grateful to R. R. Hudson and M. Antezana for advice. Many ideas presented in this paper are derived from work done by, or in collaboration with, Jan Klein, C. O'hUigin, and N. Takahata; we acknowledge with gratitude our indebtedness, but they should not be held responsible for ideas that may not be their own. Supported by NIH grant GM42397.
PY - 1996/2
Y1 - 1996/2
N2 - Human evolution exhibits repeated speciations and. conspicuous morphological change: from Australopithecus to Homo habilis, H. erectus, and H. sapiens; and from their hominoid ancestor to orangutans, gorillas, chimpanzees, and humans. Theories of founder-event speciation propose that speciation often occurs as a consequence of population bottlenecks, down to one or very few individual pairs. Proponents of punctuated equilibrium claim in addition that founder-event speciation results in rapid morphological change. The major histocompatibility complex (MHC) consists of several very polymorphic gene loci. The genealogy of 19 human alleles of the DQB1 locus coalesces more than 30 million years ago, before the divergence of apes and Old World monkeys. Many human alleles are more closely related to pongid and cercopithecoid alleles than to other human alleles. Using the theory of gene coalescence, we estimate that these polymorphisms require human populations of the order of N = 100,000 individuals for the last several million years. This conclusion is confirmed by computer simulations showing the rate of decay of the polymorphisms over time. Computer simulations indicate, in addition, that in human evolution no bottlenecks have occurred with fewer than several thousand individuals. We evaluate studies of mtDNA, Y-chromosome, and microsatellite autosomal polymorphisms and conclude that they are consistent with the MHC result that no narrow population bottlenecks have occurred in human evolution. The available molecular information favors a recent African origin of modern humans, who spread out of Africa approximately 100,000 to 200,000 years ago.
AB - Human evolution exhibits repeated speciations and. conspicuous morphological change: from Australopithecus to Homo habilis, H. erectus, and H. sapiens; and from their hominoid ancestor to orangutans, gorillas, chimpanzees, and humans. Theories of founder-event speciation propose that speciation often occurs as a consequence of population bottlenecks, down to one or very few individual pairs. Proponents of punctuated equilibrium claim in addition that founder-event speciation results in rapid morphological change. The major histocompatibility complex (MHC) consists of several very polymorphic gene loci. The genealogy of 19 human alleles of the DQB1 locus coalesces more than 30 million years ago, before the divergence of apes and Old World monkeys. Many human alleles are more closely related to pongid and cercopithecoid alleles than to other human alleles. Using the theory of gene coalescence, we estimate that these polymorphisms require human populations of the order of N = 100,000 individuals for the last several million years. This conclusion is confirmed by computer simulations showing the rate of decay of the polymorphisms over time. Computer simulations indicate, in addition, that in human evolution no bottlenecks have occurred with fewer than several thousand individuals. We evaluate studies of mtDNA, Y-chromosome, and microsatellite autosomal polymorphisms and conclude that they are consistent with the MHC result that no narrow population bottlenecks have occurred in human evolution. The available molecular information favors a recent African origin of modern humans, who spread out of Africa approximately 100,000 to 200,000 years ago.
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U2 - 10.1006/mpev.1996.0013
DO - 10.1006/mpev.1996.0013
M3 - Article
C2 - 8673287
AN - SCOPUS:0030077045
SN - 1055-7903
VL - 5
SP - 188
EP - 201
JO - Molecular Phylogenetics and Evolution
JF - Molecular Phylogenetics and Evolution
IS - 1
ER -