Recent evolutionary history of tigers highlights contrasting roles of genetic drift and selection

Armstrong, E. E. et al. (2021) Recent evolutionary history of tigers highlights contrasting roles of genetic drift and selection. Molecular Biology and Evolution, 38(6), pp. 2366-2379. (doi: 10.1093/molbev/msab032) (PMID:33592092) (PMCID:PMC8136513)

Abstract

Species conservation can be improved by knowledge of evolutionary and genetic history. Tigers are among the most charismatic of endangered species and garner significant conservation attention. However, their evolutionary history and genomic variation remain poorly known, especially for Indian tigers. With 70% of the world’s wild tigers living in India, such knowledge is critical. We re-sequenced 65 individual tiger genomes representing most extant subspecies with a specific focus on tigers from India. As suggested by earlier studies, we found strong genetic differentiation between the putative tiger subspecies. Despite high total genomic diversity in India, individual tigers host longer runs of homozygosity, potentially suggesting recent inbreeding or founding events, possibly due to small and fragmented protected areas. We suggest the impacts of ongoing connectivity loss on inbreeding and persistence of Indian tigers be closely monitored. Surprisingly, demographic models suggest recent divergence (within the last 20,000 years) between subspecies and strong population bottlenecks. Amur tiger genomes revealed the strongest signals of selection related to metabolic adaptation to cold, whereas Sumatran tigers show evidence of weak selection for genes involved in body size regulation. We recommend detailed investigation of local adaptation in Amur and Sumatran tigers prior to initiating genetic rescue.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Khan, Dr Anubhab
• Authors: Armstrong, E. E., Khan, A., Taylor, R. W., Gouy, A., Greenbaum, G., Thiéry, A., Kang, J. T., Redondo, S. A., Prost, S., Barsh, G., Kaelin, C., Phalke, S., Chugani, A., Gilbert, M., Miquelle, D., Zachariah, A., Borthakur, U., Reddy, A., Louis, E., Ryder, O. A., Jhala, Y. V., Petrov, D., Excoffier, L., Hadly, E., and Ramakrishnan, U.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Molecular Biology and Evolution
• Publisher: Oxford University Press
• ISSN: 0737-4038
• ISSN (Online): 1537-1719
• Published Online: 16 February 2021
• Copyright Holders: Copyright © The Author(s) 2021
• First Published: First published in Molecular Biology and Evolution 38(6): 2366-2379
• Publisher Policy: Reproduced under a Creative Commons licence