Homo sapiens, Homo neanderthalensis and the Denisova specimen: New insights on their evolutionary histories using whole-genome comparisons.

Vanessa Rodrigues Paixão-Côrtes,Tábita Hünemeier,Maria Cátira Bortolini,Lucas Henrique Viscardi,Francisco Mauro Salzano

doi:10.1590/s1415-47572012000600003

Vanessa Rodrigues Paixão-Côrtes, Tábita Hünemeier + Show 3 more

Open Access

https://doi.org/10.1590/s1415-47572012000600003

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Abstract

After a brief review of the most recent findings in the study of human evolution, an extensive comparison of the complete genomes of our nearest relative, the chimpanzee (Pan troglodytes), of extant Homo sapiens, archaic Homo neanderthalensis and the Denisova specimen were made. The focus was on non-synonymous mutations, which consequently had an impact on protein levels and these changes were classified according to degree of effect. A total of 10,447 non-synonymous substitutions were found in which the derived allele is fixed or nearly fixed in humans as compared to chimpanzee. Their most frequent location was on chromosome 21. Their presence was then searched in the two archaic genomes. Mutations in 381 genes would imply radical amino acid changes, with a fraction of these related to olfaction and other important physiological processes. Eight new alleles were identified in the Neanderthal and/or Denisova genetic pools. Four others, possibly affecting cognition, occured both in the sapiens and two other archaic genomes. The selective sweep that gave rise to Homo sapiens could, therefore, have initiated before the modern/archaic human divergence.

Highlights

Until recently it was believed that the first hominid genus was Australopithecus, whose fossil record is relatively broad and convincing in showing the conditions described above
There are controversies regarding the hominid phylogeny and its nomenclature, some paleoanthropologists have postulated that from Ardipithecus ramidus would have emerged the first species of the genus Australopithecus, Australopithecus anamensis (~4 million years BP), which in turn gave rise to
It is likely that Australopithecus afarensis was the ancestor of several other species currently identified as belonging to the Paranthropus genus, as well as to others classified in the genus Homo (Johanson and Edgar, 1996; Kimbel and Delezene, 2009)

Summary

Introduction

Until recently it was believed that the first hominid genus (or hominin, primates basically characterized by erect posture, bipedal locomotion and relatively large brains; Johanson and Edgar, 1996) was Australopithecus, whose fossil record is relatively broad and convincing in showing the conditions described above. In the present study we compared the Homo sapiens genome with those of Neanderthal and Denisova to explore some issues on the nature of the differences and similarities of these modern and archaic hominin lineages, an essential approach to unravel the genetic components that make us human.

Results

Conclusion