How did Ice Age climate changes link Arctic and alpine plants and animals?

During the Ice Ages of the Pleistocene Epoch, the expansion of massive ice sheets across the Northern Hemisphere forced cold-adapted species to migrate southward, far beyond their current ranges. As these glaciers covered vast areas of North America, Europe, and Asia, Arctic biota spread into regions that were previously warmer.12

This climatic shift created a link between Arctic and alpine environments through the movement of species. When global temperatures eventually rose and the ice retreated, these cold-adapted organisms were forced to migrate again to remain in suitable habitats. They moved in two primary directions: northward toward Arctic latitudes and upward into high-altitude mountainous terrain.1

This historical pattern of migration and retreat explains the striking similarities observed today between the flora and fauna of the Arctic and those found in high mountain ranges, such as the European Alps. While some alpine and Arctic animals remained specialized to their specific environments, preventing widespread intermingling, the shared history of displacement during glacial intervals remains a fundamental factor in the distribution and composition of these mountain ecosystems.13