Polar Bears Are A Heart Attack Waiting To Happen, But They Evolved That Way

Polar bears have taken up a blubber-rich diet that may leave them with up to half their body weight made up by fat. And as it turns out, most of the polar bear's genes that have undergone rapid evolution seem to be involved in keeping its cholesterol under control and its heart from exploding under the strain.
Polar Bears Are A Heart Attack Waiting To Happen, But They Evolved That Way