News release

From: The Royal Society

Dollo meets Bergmann: Morphological evolution in secondary aquatic mammals

Summary: Ever since the colonization of land by the first tetrapods, terrestrial environments have been occupied by their descendants (including most amphibians, reptiles, birds, and mammals). Over hundreds of millions of years there have been repeated evolutionary transitions back to aquatic environments. A new study investigated these transitions across the 5800+ species of living mammals and found that adaptations to aquatic environments are irreversible, making a re-adaptation to fully terrestrial lifestyle impossible. Transitioning to aquatic environments was also linked with consistent increase in body mass to reduce heat loss and was significantly more common among carnivores than herbivores.