An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
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
Early American humans hunted car-size armadillos and used their shells for houses.
12
Cats have a weak sense of taste. They have only 473 tastebuds, humans have 9,000.
307
Only humans shed emotional tears.
331
It has been scientifically proven that stroking a cat can lower one's blood pressure!
456
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82