Estimates of genetic load suggest frequent purging of deleterious alleles in small populations

作者：Tom van der Valk, Marc de Manuel, Tomàs Marquès‐Bonet, Katerina Guschanski · 发表于：bioRxiv (Cold Spring Harbor Laboratory) · 年份：2019 · DOI：10.1101/696831 · 被引用次数：75 · 研究领域：Genetic diversity and population structure、Evolution and Genetic Dynamics、Genetic and phenotypic traits in livestock

Abstract It is commonly thought that declining populations will experience negative genetic consequences as a result of increased inbreeding. Here we estimated the average deleteriousness of derived alleles in a range of mammals and found that species with historically small population size and low genetic diversity often have lower genetic load than species with large population sizes. This is likely the result of genetic purging – the more efficient removal of partially deleterious recessive alleles from inbred populations. Our findings suggest that genetic purging occurs over long evolutionary time frames, and therefore rapid population declines are likely to dis-proportionally increase mutational load in species with high diversity, as they carry many deleterious alleles that can reach fixation before genetic purging can remove them.