19:00 – 20:00
(1) Population genomics of the critically endangered spoon-billed sandpiper | лекция
The nature of genetic changes contributing to species extinction and impeding population recovery remains poorly understood. I will talk about our study of the population genetic history of the critically endangered spoon-billed sandpiper and its sister species, the red-necked stint, which is of least concern.
Using whole-genome data, we found that while the red-necked stint population was relatively constant across 200,000 years, the spoon-billed sandpiper population peaked 15,000-25,000 years ago during the last glacial maximum, when suitable breeding habitat was likely abundant, and has been declining since.
However, the level of heterozygosity of the spoon-billed sandpiper remains high, higher than is expected either in an equilibrium state, or if the population has gone through a recent bottleneck. Using modelling, we observe that the increase of the population that occurred prior to the ongoing decline could have led to accumulation of recessive deleterious polymorphisms, imposing an additional burden on the spoon-billed sandpiper population.
Thus, complex demographic changes leading to gain of deleterious genetic diversity may pose a risk to species survival and recovery by increasing the cost of inbreeding. Specifically, species that had greater habitat availability during the last glacial maximum may be especially prone to this effect.