1. Fragmented habitat compensates for the adverse effects of genetic bottleneck
- Author
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Ari Löytynoja, Pasi Rastas, Mia Valtonen, Juhana Kammonen, Liisa Holm, Morten Tange Olsen, Lars Paulin, Jukka Jernvall, Petri Auvinen, Institute of Biotechnology, Bioinformatics, Ari Pekka Löytynoja / Principal Investigator, Centre for Information Technology, Organismal and Evolutionary Biology Research Programme, Genetics, Computational genomics, Faculty of Science, Department of Geosciences and Geography, Jukka Jernvall / Principal Investigator, and DNA Sequencing and Genomics
- Subjects
runs of homozygosity ,Marine ,Evolution ,Effective population-size ,metapopulation ,Phoca-hispida ,Salmon salmo-salar ,General Biochemistry, Genetics and Molecular Biology ,Europe ,Postglacial colonization ,genetic variation ,1181 Ecology, evolutionary biology ,mammals ,habitat fragmentation ,General Agricultural and Biological Sciences ,genetic bottleneck ,pinniped - Abstract
In the face of the human-caused biodiversity crisis, understanding the theoretical basis of conservation ef-forts of endangered species and populations has become increasingly important. According to population genetics theory, population subdivision helps organisms retain genetic diversity, crucial for adaptation in a changing environment. Habitat topography is thought to be important for generating and maintaining popu-lation subdivision, but empirical cases are needed to test this assumption. We studied Saimaa ringed seals, landlocked in a labyrinthine lake and recovering from a drastic bottleneck, with additional samples from three other ringed seal subspecies. Using whole-genome sequences of 145 seals, we analyzed the distribution of variation and genetic relatedness among the individuals in relation to the habitat shape. Despite a severe his-tory of genetic bottlenecks with prevalent homozygosity in Saimaa ringed seals, we found evidence for the population structure mirroring the subregions of the lake. Our genome-wide analyses showed that the sub -populations had retained unique variation and largely complementary patterns of homozygosity, highlighting the significance of habitat connectivity in conservation biology and the power of genomic tools in under-standing its impact. The central role of the population substructure in preserving genetic diversity at the metapopulation level was confirmed by simulations. Integration of genetic analyses in conservation deci-sions gives hope to Saimaa ringed seals and other endangered species in fragmented habitats.
- Published
- 2022