Admixture Increases Genetic Diversity and Adaptive Potential in Australasian Killer Whales

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dc.citation.volumeEarly View
dc.contributor.authorReeves IM
dc.contributor.authorTotterdell JA
dc.contributor.authorSandoval-Castillo J
dc.contributor.authorBetty EL
dc.contributor.authorStockin KA
dc.contributor.authorOliphant Stewart R
dc.contributor.authorJohnstone M
dc.contributor.authorFoote AD
dc.contributor.editorKardos M
dc.coverage.spatialEngland
dc.date.accessioned2025-03-26T19:36:30Z
dc.date.available2025-03-26T19:36:30Z
dc.date.issued2025-02-28
dc.description.abstractAdmixture is the exchange of genetic variation between differentiated demes, resulting in ancestry within a population coalescing in multiple ancestral source populations. Low-latitude killer whales (Orcinus orca) populations typically have higher genetic diversity than those in more densely populated, high productivity and high-latitude regions. This has been hypothesized to be due to episodic admixture between populations with distinct genetic backgrounds. We test this hypothesis by estimating variation in local ancestry of whole genome sequences from three genetically differentiated, low-latitude killer whale populations and comparing them to global genetic variation. We find 'Antarctic-like' ancestry tracts in the genomes of southwestern Australia (SWA) population including recent (within the last 2-4 generations) admixture. Admixed individuals had, on average, shorter and fewer runs of homozygosity than unadmixed individuals and increased effective population size (Ne). Thus, connectivity between demes results in the maintenance of Ne of relatively small demes at a level comparable to the sum of Ne across demes. A subset of the admixed regions was inferred to be evolving under selection in the SWA population, suggesting that this admixed variation may be contributing to the population's adaptive potential. This study provides important and rare empirical evidence that small populations can maintain genetic diversity due to sporadic admixture between different genetic backgrounds and that admixed ancestry can promote the long-term stability of Ne.
dc.description.confidentialfalse
dc.format.paginatione17689-
dc.identifier.author-urlhttps://www.ncbi.nlm.nih.gov/pubmed/40019383
dc.identifier.citationReeves IM, Totterdell JA, Sandoval-Castillo J, Betty EL, Stockin KA, Oliphant Stewart R, Johnstone M, Foote AD. (2025). Admixture Increases Genetic Diversity and Adaptive Potential in Australasian Killer Whales.. Mol Ecol. Early View. (pp. e17689-).
dc.identifier.doi10.1111/mec.17689
dc.identifier.eissn1365-294X
dc.identifier.elements-typejournal-article
dc.identifier.issn0962-1083
dc.identifier.numbere17689
dc.identifier.urihttps://mro.massey.ac.nz/handle/10179/72693
dc.languageeng
dc.publisherJohn Wiley and Sons Ltd
dc.publisher.urihttps://onlinelibrary.wiley.com/doi/10.1111/mec.17689
dc.relation.isPartOfMol Ecol
dc.rights(c) 2025 The Author/s
dc.rightsCC BY 4.0
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.subjectcetacean
dc.subjecteffective population size
dc.subjectheterosis
dc.subjectinbreeding
dc.subjectintrogression
dc.titleAdmixture Increases Genetic Diversity and Adaptive Potential in Australasian Killer Whales
dc.typeJournal article
pubs.elements-id499950
pubs.organisational-groupOther
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