The genomic rate of adaptive evolution.
The role of positive darwinian selection in evolution at the molecular level has been keenly debated for many years, with little resolution. However, a recent increase in DNA sequence data and the development of new methods of analysis have finally made this question tractable. Here, I review the current state-of-play of the field. Initial estimates in Drosophila suggest that approximately 50% of all amino acid substitutions, and a substantial fraction of substitutions in non-coding DNA, have been fixed as a consequence of adaptive evolution. Estimates in microorganisms are even higher. By contrast, there is little evidence of widespread adaptive evolution in our own species.
Eyre-Walker
Adam
A
National Evolutionary Synthesis Center, Durham, NC 27705, USA. a.c.eyre-walker@sussex.ac.uk
D000222:Adaptation, Physiological / Q000235:genetics*; D005075:Biological Evolution; D023281:Genomics / Q000379:methods*; D013997:Time Factors