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 human brain produces as many as 12,000 to 50,000 thoughts per day, depending on how deep a thinker a person is.
23
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
Having sex can make a woman look younger and more attractive due to the release of estrogen and collagen.
346
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Mushrooms are more closely related to humans than they are to plants.
47
Your thumb is about the same size as your nose.
124
Human hair and fingernails continue to grow after death.
7