Adaptive changes in polar bear genetics allow them to eat a diet high in blubber from marine prey, without clogging their arteries and having a heart attack. Because polar bears live in such a harsh environment, in order to survive they have to rely on stored fat, which makes up half the weight of their bodies.
Adaptive changes in polar bear genetics allow them to eat a diet high in blubber from marine prey, without clogging their arteries and having a heart attack.
Because polar bears live in such a harsh environment, in order to survive they have to rely on stored fat, which makes up half the weight of their bodies.
Researchers from the University of California, Berkeley working with scientists in China and Denmark, studied the genetic differences between polar bears and the closely related brown bears that eat a much lower-fat diet that usually includes a lot of vegetation.
Genetic evidence suggests that the two species diverged less than 500 thousand years ago.
Rasmus Nielsen, an evolutionary geneticist at the University of California, Berkeley, is quoted as saying: “In this short amount of time, polar bears have adapted to the cold environment of the Arctic and to a new diet. We see the footprints of this adaptation in the genome of the polar bear.”
Previous estimates aimed as far back as 5 million years ago for the origin of polar bears, but according to the results of the latest study, polar bears adapted very quickly to the colder climate.
