Meeting Abstract
Isolated in one of the most extreme marine environments on earth, the teleost fish fauna of Antarctica’s Southern Ocean is dominated by one clade: notothenioids. However, as this region undergoes some of the fastest rates of environmental change, the long-term persistence of this unique fauna is jeopardized. Forecasting the response of these species to contemporary environmental perturbations requires an understanding of how notothenioids have persisted through climatic change events over their evolutionary history. Do shifts in climatic regimes correspond with changes in biogeography or pulses of extinction? Here we use a combination of phylogenetic and biogeographic modeling to infer the biogeographic history of living notothenioid fishes. We show that the High Antarctic represents a biodiversity sink. In contrast, sub-polar regions, specifically the Northern Antarctic Peninsula, have repeatedly acted as source areas for the recolonization of teleost fish biodiversity in the High Antarctic. Contemporary trends of global climate change threaten to invert these evolutionary dynamics of lineage expansion out of the Antarctic Peninsula. Today, this evolutionary refugium and speciation zone is poised to become a main entry point for invasive colonizers, while simultaneously disrupting connectivity between the Southern Ocean’s high latitudes and surrounding sub-Antarctic areas.
