9 Answers To Science Questions You All Had As Kids

6. Why Don€™t Humans Have Tails?

Doesn't seem fair, does it?

The simple answer is basically because we don't need one.

If we consider what animals with tails actually use them for, you can see why. Many quadrupeds use it for balance, some have developed a prehensile tail to grab on to branches, swimming animals tend to use it for propulsion, birds use them to steer and animals such as horses use them to swat away flies.

Humans have found alternative ways to do all of these things, largely by standing on two legs and freeing up our hands. In fact, standing up on two legs may well have been what did it for the tail.

It wasn't so much human that lost their tails, but the common ancestor that we share with a lot of other tail-less primates. We, and most primates for that matter, actually do begin life with a tail in the womb, this is usually absorbed back in as the foetus develops.

Some people are born with a tail due to a condition called Atavism, which is essentially the re-expression of a genetic throwback that is still locked up in your DNA.

Whilst a bit of butt candy is useful for counterbalancing the weight of your head when you walk on all fours, having one as a biped might actually throw us off balance. To imagine how it might look to walk on two legs with a tail, just imagine a T-Rex. Not sexy.