Figure 1: A European roe deer (Capreolus capreolus). Along with the Siberian roe deer (C. pygargus), these species are the only two artiodactyls capable of obligate diapause, which allows the timing of the birth of offspring to coincide with favourable environmental conditions.
The intensive climate fluctuations of the Pleistocene have had an outsized influence on genetic diversity and geographic structure of animal and plant populations (Hofreiter & Stewart, 2009). However, distinguishing whether patterns of contemporary genetic diversity in a population are consistent with the impacts of past/ongoing selection, historical demography, or both, can be a challenging endeavour (Fig. 2 ). The historical demography of a population also directly influences natural selection: the relative importance of stochastic processes increases with reduced effective population size (Ne ), limiting the efficacy of selection (Kimura, Maruyama, & Crow, 1963). Therefore, considering both natural selection and demography together can greatly add to our understanding of evolutionary dynamics in general, and of focal species in particular. In this study, de Jong et al. (2020) not only consider the impact of demography and selection, but how these forces acted at different time scales during the evolution of roe deer (Capreolus spp.), through genomic analyses at multiple taxonomic levels (Fig. 3 ).
[ Fig. 2 uploaded separately as pdf]