Natural distributions of mitochondrial sequence diversity support new null hypotheses.
A variety of forces and constraints can cause sequence data to deviate from patterns predicted under strict neutrality. Here, I present a meta-analysis of available aligned sequence data from 12 higher animal taxa to identify whether the typical null assumption for an often-used test for neutrality--Tajima's D statistic--is an appropriate or useful null given large numbers of empirical observations. Across 1068 cytochrome oxidase I (COI) datasets, the mean value for Tajima's D is -0.391, with over a sixth of these datasets representing "significant" divergence from null assumptions according to this test. These results indicate a persistent trend for mitochondrial COI data--chosen for their prevalence in population and taxonomic studies--to indicate patterns of diversity that deviate from a purely neutral description, and provide compelling support for the concept that more complex "null" hypotheses may be necessary in population genetics.
Wares
John P
JP
Department of Genetics, University of Georgia, Athens, Georgia 30602, USA. jpwares@uga.edu
D000818:Animals; D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV / Q000235:genetics*; D019143:Evolution, Molecular; D014644:Genetic Variation
D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV