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
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
One human hair can support 3 ounces.
191
On average a woman has 4 sexual partners in her lifetime.
-143
If the human eye was a digital camera, it would have 576 megapixels.
25
It takes approximately 12 hours for food to entirely digest.
93
The human eye blinks an average of 4,200,000 times a year.
233