Killer whale genomes reveal a complex history of recurrent admixture and vicariance
International audience Reconstruction of the demographic and evolutionary history of populations assuminga consensus tree‐like relationship can mask more complex scenarios, which areprevalent in nature. An emerging genomic toolset, which has been most comprehensivelyharnessed in the reconstruction o...
Published in: | Molecular Ecology |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Other Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2019
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Subjects: | |
Online Access: | https://hal.science/hal-02263580 https://doi.org/10.1111/mec.15099 |
Summary: | International audience Reconstruction of the demographic and evolutionary history of populations assuminga consensus tree‐like relationship can mask more complex scenarios, which areprevalent in nature. An emerging genomic toolset, which has been most comprehensivelyharnessed in the reconstruction of human evolutionary history, enablesmolecular ecologists to elucidate complex population histories. Killer whales havelimited extrinsic barriers to dispersal and have radiated globally, and are thereforea good candidate model for the application of such tools. Here, we analyse a globaldata set of killer whale genomes in a rare attempt to elucidate global populationstructure in a nonhuman species. We identify a pattern of genetic homogenisationat lower latitudes and the greatest differentiation at high latitudes, even betweencurrently sympatric lineages. The processes underlying the major axis of structureinclude high drift at the edge of species' range, likely associated with founder effectsand allelic surfing during postglacial range expansion. Divergence between Antarcticand non‐Antarctic lineages is further driven by ancestry segments with up to fourfoldolder coalescence time than the genome‐wide average; relicts of a previousvicariance during an earlier glacial cycle. Our study further underpins that episodicgene flow is ubiquitous in natural populations, and can occur across great distancesand after substantial periods of isolation between populations. Thus, understandingthe evolutionary history of a species requires comprehensive geographic samplingand genome‐wide data to sample the variation in ancestry within individuals. |
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