Modern humans first appeared about 200,000 years ago, but record keeping didn't begin until about 6,000 years ago. That means about 97% of human history is lost.
21
A person can live without food for about a month, but only about a week without water.
156
On average, there's 100 billion neurons in the human brain.
83
We share 70% of our DNA with a slug.
218
On average a woman has 4 sexual partners in her lifetime.
-143
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
A man's beard grows fastest when he anticipates sex.
239
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14