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
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Your heart will pump about 212 million liters in its lifetime.
26
Early American humans hunted car-size armadillos and used their shells for houses.
12
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
The human body contains over a billion miles of DNA.
147
A human brain produces as many as 12,000 to 50,000 thoughts per day, depending on how deep a thinker a person is.
23
One human hair can support 3 ounces.
191