Genetic Secrets of Steller’s Sea Cow Revealed genetics science
the coastal areas of the North Pacific Ocean — including the Bering Sea — during the Pleistocene and Holocene epoch.
Adult Steller’s sea cows reached a length of 10 m , weighed over 10 tons, and stored up to 10 cm of blubber in some areas of the body. This made them ideal resources for human hunters, who exploited them for meat, fat, and skin. “The archeological record is not very good, but from the demographic analysis of the genomes it looks like their population had been declining for at least a half million years or so,” said Professor Beth Shapiro, a researcher in the Department of Ecology and Evolutionary Biology and the Howard Hughes Medical Institute at the University of California, Santa Cruz.
Scanning the genomes of other marine mammals, the scientists found that the lipoxygenase genes inactivated in Steller’s sea cows are also inactivated in whales and otherCetaceans shed their outer layer of skin rapidly, which prevents the buildup of thick skin that would otherwise occur in the absence of the lipoxygenase enzymes.