The influence of migration and habitat on vertebrate genetic diversity

<p>Genetic diversity (GD) is largely determined by effective population size, which may differ dramatically for related species that differ in key aspects of their biology.  We examined relationships among GD (microsatellite heterozygosity and allelic richness), taxonomic Class, habitat, and migratory tendencies.  Weighted regression revealed that migratory fishes, amphibians, and reptiles had less GD compared to non-migratory species whereas migratory birds and mammals had more GD.  We suggest that these differences are a result of differences in selection between terrestrial and aquatic species, differences in vagility, and the incidence of philopatry among the Classes.  We also found that the effects of biome on GD influence migratory and non-migratory species differently:  migratory, tropical amphibians and birds are more genetically diverse than migratory, polar/temperate amphibians and birds.  However, we found the reverse relationship (i.e., decreased GD in tropical, migratory species compared to polar/temperate migratory species) in mammals and no influence of habitat on GD in migratory fishes or reptiles.  These differences likely arose due to abiotic or anthropogenic effects that influence effective population size and reflect important biologic differences between vertebrate Classes.</p>