Life history traits predict demographic responses to global warming in Arctic marine mammals

The glacial-interglacial transitions during the Late Quaternary effected the thickness and extent of glaciers and ice sheets as well as sea level height and ocean circulation patterns. These environmental changes altered the ecological conditions of many species both at high and low latitudes, and hence were evolution-driving forces. Here, we asked whether the Late Quaternary changes in the marine environment induced cross-taxa responses to widespread climatic stressors or whether only species-specific response occurred. Additionally, we asked whether demographic dynamics of marine species, in this case, marine mammals, have distinctive genetic signatures. The different life history traits within marine mammal species provide a unique opportunity to address these questions. We employed genetic data to infer the demographic history of marine mammal species inhabiting the Arctic with contrasting habitats and/or life history traits. This included resident, ice obligate species (e.g., polar bears, ringed seals, bearded seals, walrus), ice associated species (e.g., narwhals, belugas, bowhead whales) and temperate/non-resident species (e.g., minke and blue whales, harbor seals). The relative trend in the demographic response was consistent among species with similar habitat requirements and life history traits. Population size changes were correlated with periods of climate oscillations.