Explained: How human beings lost their tails

For half a billion years or so, our ancestors sprouted tails. As fish, they used their tails to swim through the Cam­brian seas. Much later, when they evolved into primates, their tails helped them stay balanced as they raced from branch to branch through Eocene jungles. But then, roughly 25 million years ago, the tails disappeared.

Charles Darwin first recognised this change in our ancient anatomy. But how and why it happened has remained a mystery.

Now a team of scientists in New York say they have pinpointed the genetic mutation that may have erased our tails. When the scientists made this