Evolution: natural selection in the evolution of humans and chimps

Area of Science:

• Genomics
• Evolutionary Biology
• Comparative Genomics

Background:

• Near-complete sequencing of human and chimpanzee genomes is now available.
• Genomic comparison offers insights into human and chimp evolutionary paths.

Purpose of the Study:

• To identify genes that have undergone adaptive evolution in the human and chimp lineages.
• To quantify the impact of natural selection on coding sequences since the divergence of humans and chimpanzees.

Main Methods:

• Comparative genomic analysis of human and chimpanzee genomes.
• Identification and analysis of genetic variations and amino acid changes in coding sequences.

Main Results:

• Several hundred genes show strong evidence of adaptive evolution.
• An estimated 75% of amino acid substitutions in coding regions have been eliminated by natural selection.
• The actual number of adaptively evolved genes may be considerably higher than currently identified.

Conclusions:

• Comparative genomics provides a powerful tool for understanding evolutionary adaptation.
• Natural selection has played a substantial role in shaping the human and chimp genomes, particularly by removing deleterious amino acid changes.