Data from: Looking into the past – the reaction of three grouse species to climate change over the last million years using whole genome sequences

Tracking past population fluctuations can give insight into current levels
of genetic variation present within species. Analysing population dynamics
over larger time scales can be aligned to known climatic changes to
determine the response of species to varying environments. Here, we
applied the Pairwise Sequentially Markovian Coalescent (PSMC) model to
infer past population dynamics of three widespread grouse species; black
grouse, willow grouse and rock ptarmigan. This allowed the tracking of the
effective population size (Ne) of all three species beyond 1 Mya,
revealing that i) early Pleistocene cooling (~2.5 Mya) caused an increase
in the willow grouse and rock ptarmigan populations, ii) the mid-Brunhes
event (~430 kya) and following climatic oscillations decreased the Ne of
willow grouse and rock ptarmigan, but increased the Ne of black grouse and
iii) all three species reacted differently to the last glacial maximum
(LGM) – black grouse increased prior to it, rock ptarmigan experienced a
severe bottleneck and willow grouse was maintained at large population
size. We postulate that the varying PSMC signal throughout the LGM depicts
only the local history of the species. Nevertheless, the large population
fluctuations in willow grouse and rock ptarmigan indicate that both
species are opportunistic breeders while black grouse tracks the climatic
changes more slowly and is maintained at lower Ne. Our results highlight
the usefulness of the PSMC approach in investigating species’ reaction to
climate change in the deep past, but also that caution should be taken in
drawing general conclusions about the recent past.