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
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Obsessive nose picking is called Rhinotillexomania.
101
A man's beard grows fastest when he anticipates sex.
239
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The average person's skin weighs twice as much as their brain.
131