What is the secret to a long life? The heartbeat of some animals may hold a clue.
Studies have concluded that mammals get about a billion heartbeats per lifetime. They can use them at a rate of a thousand per minute, like the shrew, or space them out into slow, ponderous beats, over many years, as is the case for the grey whale. But there are notable exceptions. Some species get more than their fair billion beats. The extent to which these species live beyond a billion beats must depend, in part, upon unique features of their biology. Whatever these features […]