It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Crying literally alleviates stress and uniquely allows humans to decrease feelings of anger and sadness.
24
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
139
Your fingernails grow faster in summer.
744
We share 70% of our DNA with a slug.
218
Only humans shed emotional tears.
331
One human hair can support 3 ounces.
191