The Myth of Eve: Molecular Biology and Human Origins: F. J. Ayala

@article{Ayala1995TheMO,
  title={The Myth of Eve: Molecular Biology and Human Origins: F. J. Ayala},
  author={Francisco Jos{\'e} Ayala},
  journal={Science},
  year={1995},
  volume={270},
  pages={1930 - 1936}
}
  • F. Ayala
  • Published 22 December 1995
  • Biology
  • Science
It has been proposed that modern humans descended from a single woman, the "mitochondrial Eve" who lived in Africa 100,000 to 200,000 years ago. The human immune system DRB1 genes are extremely polymorphic, with gene lineages that coalesce into an ancestor who lived around 60 million years ago, a time before the divergence of the apes from the Old World monkeys. The theory of gene coalescence suggests that, throughout the last 60 million years, human ancestral populations had an effective size… 
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A profound change in haplotype frequencies from Africans to non-Africans supports a possible bottleneck during the dispersion of modern humans from Africa.
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TLDR
A rigorous analysis of allelic genealogies in this gene family cannot be used to justify the claim that the lineage leading to modern humans contained on average at least 100,000 individuals, according to prior assertions.
MODELING THE GENETIC ARCHITECTURE OF MODERN POPULATIONS
TLDR
How the magnitude and fluctuation of this number over time is important for evaluating competing hypotheses about the nature of human evolution during the Pleistocene is discussed.
Population size at the time of mitochondrial eve
TLDR
A computer simulation is used to investigate the relation between the age of the authors' most recent mitochondrial DNA ancestor (often called “mitochondrial Eve”) and the number of her contemporaries, following a female population through 16,000 generations, allowing it to fluctuate at random, although guided by a growth rate of .02% per generation.
Recent origin of HLA-DRB1 alleles and implications for human evolution
TLDR
The coalescence time of alleles within allelic lineages indicates that the effective population size for early hominids (over the last 1 Myr) was approximately 104 individuals, similar to estimates based on other nuclear loci and mitochondrial DMA.
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References

SHOWING 1-10 OF 103 REFERENCES
Molecular genetics of speciation and human origins.
TLDR
The MHC and other molecular polymorphisms are consistent with a "multiregional" theory of Pleistocene human evolution that proposes regional continuity of human populations since the time of migrations of Homo erectus to the present, with distinctive regional selective pressures and occasional migrations between populations.
African populations and the evolution of human mitochondrial DNA.
TLDR
The African origin hypothesis of human mtDNA evolution is supported by two statistical tests and two hypervariable segments of mtDNA were sequenced from 189 people of diverse geographic origin, including 121 native Africans.
Genetic evidence on modern human origins.
TLDR
Genetic evidence supports the "weak Garden of Eden" hypothesis, which holds that the human populations separated some 100,000 years ago but did not expand until tens of thousands of years later.
Allelic genealogy and human evolution.
TLDR
Although the population structure prior to the late Pleistocene is less clear, the nature of Mhc polymorphism suggests that the effective size of populations leading to humans was as large as 10(5), hence, the effective population size of humans might have become somewhat smaller in most of the late pleistocene.
Matrix correlation tests support a single origin for modern humans
TLDR
The first quantitative test of the fossil evidence for each of these models of human origins is given, finding that a single African and/or Levantine origin for modern humans is supported.
Mitochondrial COII sequences and modern human origins.
TLDR
The mitochondrial DNA sequence data from COII and ND4-5 regions therefore do not support this multiregional hypothesis for the emergence of modern humans and are compatible with a 1-Myr-old human mitochondrial ancestor.
Ancient roots for polymorphism at the HLA-DQ alpha locus in primates.
  • U. Gyllensten, H. Erlich
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1989
TLDR
Most of the polymorphism at the DQ alpha locus in the human species was already present at least 5 million years ago in the ancestral species that gave rise to the chimpanzee, gorilla, and human lineages, however, one of the D Q alpha alleles may have arisen after speciation by recombination between two ancestral alleles.
MHC polymorphism pre-dating speciation
TLDR
Evidence is presented for an alternative explanation of the origin of MHC polymorphism: a large part of the M HC polymorphism pre-dates speciation and is passed on from species to species.
Sequence variation of the human Y chromosome
TLDR
The coalescence time estimated from the Y chromosome sample is more recent than that of the mitochondria! genome, which could have been caused by the selected sweep of an advantageous Y chromosome or extensive migration of human males.
Recent African origin of modern humans revealed by complete sequences of hominoid mitochondrial DNAs.
TLDR
The shallow ancestry of human mtDNAs, together with the observation that the African sequence is the most diverged among humans, strongly supports the recent African origin of modern humans, Homo sapiens sapiens.
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