Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
It takes about 20 seconds for a red blood cell to circle the whole body.
102
A man's beard grows fastest when he anticipates sex.
239
Every human spent about half an hour as a single cell.
144
The average sperm cell swims at 8 inches per hour.
4
A person can live without food for about a month, but only about a week without water.
156