Genome-wide analyses reveal drivers of penguin diversification
Juliana A. Vianna, Flávia A. N. Fernandes, María José Frugone, Henrique V. Figueiró, Luis R. Pertierra, Daly Noll, Ke Bi, Cynthia Y. Wang‐Claypool, Andrew Lowther, Patricia G. Parker, Céline Le Bohec, Francesco Bonadonna, Bárbara Wienecke, Pierre Pistorius, Antje Steinfurth, Christopher P. Burridge, Gisele Pires de Mendonça Dantas, Élie Poulin, W. Brian Simison, J. B. Henderson, Eduardo Eizirik, Mariana F. Nery, Rauri C. K. Bowie
Abstract
Significance Penguins have long been of interest to scientists and the general public, but their evolutionary history remains unresolved. Using genomes, we investigated the drivers of penguin diversification. We found that crown-group penguins diverged in the early Miocene in Australia/New Zealand and identified Aptenodytes (emperor and king penguins) as the sister group to all other extant penguins. Penguins first occupied temperate environments and then radiated to cold Antarctic waters. The Antarctic Circumpolar Current’s (ACC) intensification 11.6 Mya promoted penguin diversification and geographic expansion. We detected interspecies introgression among penguins, in some cases following the direction of the ACC, and identified genes acting on thermoregulation, oxygen metabolism, and diving capacity that underwent adaptive evolution as they progressively occupied more challenging thermal niches.