One of the big differences between women and men has been explained.

Usually, men have bigger noses than women - and you can blame evolution.  

Researchers say it may be because men have more muscle, and that demands more oxygen and a bigger nose to breathe it in.

Men also have bigger nasal cavities and generally take in more oxygen while breathing than women.

This may also explain why human ancestors like Neanderthals had bigger noses -- not just better to smell you with (so you can be hunted), but to take in more oxygen to keep the bigger muscles working.

-Rob Archer