It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
In ancient Egypt, priests plucked EVERY hair from their bodies, including their eyebrows and eyelashes.
130
The human body contains over a billion miles of DNA.
147
Enamel is hardest substance in the human body.
61
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
If the human eye was a digital camera, it would have 576 megapixels.
25
Cats have a weak sense of taste. They have only 473 tastebuds, humans have 9,000.
307