2017/06/22 by Alicia Abadía-Cardoso, Alicia Abadía‐Cardoso, Nelson B Freimer +2 · 30 citations
Biochemistry, Genetics and Molecular Biology · Environmental Science · #Allele #Biology #Demographic history #Demography #Ecology #Effective population size #Elephant seal #Evolutionary biology #Fur seal #Genetic diversity #Genetic diversity and population structure #Genetic drift #Genetic variation #Genetics #Genomics and Phylogenetic Studies #Marine animal studies overview #Microsatellite #Population #Population bottleneck #Population genetics #Threatened species #Zoology
paper · pdf · doi:10.1093/jhered/esx053
published in Journal of Heredity 108(6), 618-627 (Oxford University Press)
openalex publication_date 2017/06/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The northern elephant seal, Mirounga angustirostris, was heavily hunted and declared extinct in the 19th century. However, a colony remained on remote Guadalupe Island, Mexico and the species has since repopulated most of its historical distribution. Here, we present a comprehensive evaluation of genetic variation in the species. First, we assess the effect of the demographic bottleneck on microsatellite variability and compare it with that found in other pinnipeds, demonstrating levels of variation similar to that in species that continue to be threatened with extinction. Next, we use sequence data from these markers to demonstrate that some of the limited polymorphism predates the bottleneck. However, most contemporary variation appears to have arisen recently and persisted due to exponential growth. We also describe how we use the range in allele size of microsatellites to estimate ancestral effective population size before the bottleneck, demonstrating a large reduction in effective size. We then employ a classical method for bacteria to estimate the microsatellite mutation rate in the species, deriving an estimate that is extremely similar to that estimated for a similar set of loci in humans, indicating consistency of microsatellite mutation rates in mammals. Finally, we find slight significant structure between some geographically separated colonies, although its biological significance is unclear. This work demonstrates that genetic analysis can be useful for evaluating the population biology of the northern elephant seal, in spite of the bottleneck that removed most genetic variation from the species.