Size Does Not Matter for Mitochondrial DNA

摘要

On page 570 of this issue, Bazin etal. (1) test one of the most basic predictions of population genetics: that species with large population sizes should have more genetic diversity than species with small popu-lation sizes. They find that this prediction, as expected, is upheld for diversity in nuclear genes, but that there is no correspondence between population size and genetic diversity for mito-chondrial genes. Bazin et al conducted their analysis by first compiling an impressive DNA diversity data set for both nuclear and mitochondrial DNA. Using an automated system, they searched the GenBank and EMBL databases for instances in which the same gene had been sequenced in multiple individuals of a species This yielded, after some restrictions toimprove data quality, 417 species for which they had diversity data for nuclear DNA and 1683 species for mitochondiial DNA. They also analyzed a data set of 912 species for which allozyme diversity data were available.