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).