Genome-wide analyses reveal demographic trajectories of penguin during the Last Glaciation

Inferring population sizes is crucial to understanding how the wild species adapt to the changing environments during the evolution. Penguins are vulnerable to changes in habitat and prey distribution caused by climate. In this work, I inferred the effective population sizes of 6 penguin genera (Aptenodytes, Eudyptes, Eudyputa, Megadyptes, Pygoscelis, and Spheniscus) using the pairwise sequencially Markovian coalescent model with Beta distribution based on the whole-genome sequence data. The results showed that there were two different demographic trajectories of penguin during the Last Glaciation. One demographic trajectory of penguin is that the effective population size increased until to the Last Glacial Maximum (LGM), and then declined. The other demographic trajectory is that the effective population size was steady low during the Last Glaciation. The two kinds of demographic trajectories of penguin suggest that penguins possibly originated from tropical areas and diversified the habitats to colder Antarctic and warmer equatorial areas over millions of years.