Comparative population genomics in animals uncovers the determinants of genetic diversity

Genome-wide DNA polymorphism analysis across 76 animal species reveals a strong effect of ecological strategies, and particularly parental investment, on species levels of genetic diversity. Genetic diversity related to parenting styles This study tackles the intriguing question of why some species are genetically highly polymorphic and others are not. The authors look at genetic diversity of 76 non-model animal species by sequencing their transcriptomes. They find that the distribution of genetic diversity among these species has no detectable influence on geographic range or invasive status, but can be accurately predicted by key species traits related to parental investment. For example, long-lived or low-fecundity species with brooding ability are less genetically diverse than short-lived or highly fecund ones. Showing the influence of long-term life history strategies on species response to short-term environmental perturbations has implications for conservation policies. Genetic diversity is the amount of variation observed between DNA sequences from distinct individuals of a given species. This pivotal concept of population genetics has implications for species health, domestication, management and conservation. Levels of genetic diversity seem to vary greatly in natural populations and species, but the determinants of this variation, and particularly the relative influences of species biology and ecology versus population history, are still largely mysterious 1 , 2 . Here we show that the diversity of a species is predictable, and is determined in the first place by its ecological strategy. We investigated the genome-wide diversity of 76 non-model animal species by sequencing the transcriptome of two to ten individuals in each species. The distribution of genetic diversity between species revealed no detectable influence of geographic range or invasive status but was accurately predicted by key species traits related to parental investment: long-lived or low-fecundity species with brooding ability were genetically less diverse than short-lived or highly fecund ones. Our analysis demonstrates the influence of long-term life-history strategies on species response to short-term environmental perturbations, a result with immediate implications for conservation policies.