Dear Colleagues, On behalf of my co-authors, I am excited to announce the publication of our manuscript titled "Admixture Increases Genetic Diversity and Adaptive Potential in Australasian Killer Whales" in Molecular Ecology. Abstract: Admixture 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. For full details, please see the article, available via open access here<https://onlinelibrary.wiley.com/doi/10.1111/mec.17689?af=R>. Kind regards, Isabella Isabella Reeves (she/her) PhD Candidate BSc Marine Biology (Hons.) Cetacean Research Centre, WA Southern Shark Ecology Group College of Science & Engineering, Flinders University Email<mailto:isabella.reeves@flinders.edu.au> | Twitter<https://twitter.com/bellaa_reeves> | LinkedIn<https://www.linkedin.com/in/isabella-reeves-60142b175/> [cid:cd32ec95-51b1-4e27-9f14-e588c27f9062][cid:2b0d0041-8cee-4ed3-9c3e-ede8be38b625] I acknowledge the Kaurna people, the Traditional Custodians of the land I am fortunate to live on. I pay respect to elders past, present and emerging, and recognise the continuing connection to the land, water, culture and community of First Nations people here and across Australia. CRICOS No: 00114A This email and any attachments may be confidential. If you are not the intended recipient, please inform the sender by reply email and delete all copies of this message.
