Credit: Carl Buell
A new study shows that the similarly smooth, nearly hairless skin of whales and hippopotamuses evolved independently. The work suggests that their last common ancestor was likely a land-dwelling mammal, uprooting current thinking that the skin came fine-tuned for life in the water from a shared amphibious ancestor. The study is published today in the journal
Current Biology and was led by researchers at the American Museum of Natural History; University of California, Irvine; University of California, Riverside; Max Planck Institute of Molecular Cell Biology and Genetics; and the LOEWE-Centre for Translational Biodiversity Genomics (Germany).
"How mammals left terra firma and became fully aquatic is one of the most fascinating evolutionary stories, perhaps rivaled only by how animals traded water for land in the first place or by the evolution of flight," said John Gatesy, a senior research scientist in the American Museum of Natural History's Division of Vertebrate Zoology and a corresponding author on the study. "Our latest findings contradict the current dogma in the field--that relatives of the amphibious hippo might have been part of the transition as mammals re-entered life in the water."