When did the major demographic expansion of Pardosa astrigera populations occur across continental East Asia?

During the Last Glacial Period.

While the major evolutionary splits within Lycosidae occurred deep in the Cenozoic era, the distributional patterns seen in contemporary species have been profoundly shaped by recent, intense climate fluctuations of the Pleistocene. A case study focusing on the East Asian species *Pardosa astrigera* illustrates this recent demographic history. Although genetic analysis showed that this widespread species has two sympatric lineages that separated during the mid-Pleistocene (about 1.69 Ma), the most significant event regarding population size and spread happened much more recently. The primary demographic expansion of *P. astrigera* across the broad continental landscape of East Asia is estimated to have taken place during the relatively recent Last Glacial Period, approximately 74,340 years ago, driven by cycles of contraction into refugia during cold phases and subsequent expansion during warmer interglacials.