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
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Your heart will pump about 212 million liters in its lifetime.
26
Cats have a weak sense of taste. They have only 473 tastebuds, humans have 9,000.
307
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
Shark corneas are used in eye transplants and shark bone marrow can be used to graft human bones.
132
Your fingernails grow faster in summer.
744