Congratulations to @amandalindahl.bsky.social for successfully presenting her research in the Half-Time PhD seminar titled âAll Things Rodents: Exploring Sex Ratios and Population Structure Across Timeâ! đđ§Źâł Many thanks to the committee!
Itâs always been a mystery to me how the genetic diversity and composition of the Scandinavian brown bear originated đ€
Today, we publish a new paper that sheds new light on this, and a real-time example of how mito-nuclear discordances can evolve during severe bottlenecks:
doi.org/10.1098/rsos...
We analyzed whole genome data from bears before and after a severe bottleneck that occurred ca 100 years ago. Interestingly, although the population was reduced by ca 97%, individual genome-wide heterozygosity and inbreeding levels appear similar in bears before and after the bottleneck
This study highlights the importance of gene flow to avoid inbreeding after severe bottlenecks. However, bottlenecks still cause a loss of unique alleles, which might affect a population's ability to adapt to future challenges.
Our results suggest that male-mediated gene flow after the bottleneck, mainly from northern to southern Scandinavia, helped keep inbreeding levels low and maintain individual genetic diversity in the population. Go male bears!