Our ancient animal ancestors had tails. Why don’t we?

By CHRISTINA LARSON
AP Science Writer

WASHINGTON (AP) — Scientists have identified a gene mutation that may explain why we don’t have tails. Our very ancient animal ancestors had tails. But when apes diverged from monkeys, our branch of the tree of life shed its tail. From Darwin’s time, scientists have wondered why _ and how _ this happened. Now, researchers have identified at least one of the key genetic tweaks that led to this change. The authors caution that other genetic changes may also play a role. Their work was published Wednesday in the journal Nature.