Large- and small-scale geographic structures affecting genetic patterns across populations of an Alpine butterfly

Dispersal from the Qinghai-Tibet plateau by a high-altitude butterfly is associated with rapid expansion and reorganization of its genome

Parnassius glacialis is a typical "Out of the QTP" alpine butterfly that originated on the Qinghai-Tibet Plateau (QTP) and dispersed into relatively low-altitude mountainous. Here we assemble a chromosome-level genome of P. glacialis and resequence 9 populations in order to explore the genome evolution and local adaptation of this species. These results indicated that the rapid accumulation and slow unequal recombination of transposable elements (TEs) contributed to the formation of its large genome. Several ribosomal gene families showed extensive expansion and selective evolution through transposon-mediated processed pseudogenes. Additionally, massive structural variations (SVs) of TEs affected the genetic differentiation of low-altitude populations. These low-altitude populations might have experienced a genetic bottleneck in the past and harbor genes with selective signatures which may be responsible for the potential adaptation to low-altitude environments. These results provide a foundation for understanding genome evolution and local adaptation for "Out of the QTP" of P. glacialis.

Hilltopping influences spatial dynamics in a patchy population of tiger moths

Dispersal is a key driver of spatial population dynamics. Dispersal behaviour may be shaped by many factors, such as mate-finding, the spatial distribution of resources, or wind and currents, yet most models of spatial dynamics assume random dispersal. We examined the spatial dynamics of a day-flying moth species (Arctia virginalis) that forms mating aggregations on hilltops (hilltopping) based on long-term adult and larval population censuses. Using time-series models, we compared spatial population dynamics resulting from empirically founded hilltop-based connectivity indices and modelled the interactive effects of temperature, precipitation and density dependence. Model comparisons supported hilltop-based connectivity metrics including hilltop elevation over random connectivity, suggesting an effect of hilltopping behaviour on dynamics. We also found strong interactive effects of temperature and precipitation on dynamics. Simulations based on fitted time-series models showed lower patch occupancy and regional synchrony, and higher colonization and extinction rates when hilltopping was included, with potential implications for the probability of persistence of the patch network. Overall, our results show the potential for dispersal behaviour to have important effects on spatial population dynamics and persistence, and we advocate the inclusion of such non-random dispersal in metapopulation models.