Crying literally alleviates stress and uniquely allows humans to decrease feelings of anger and sadness.
24
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
If Earth's life was compressed into 1 year, then humans would have been around for only 2 seconds.
15
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
Only humans shed emotional tears.
331
After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
139
The human brain doesn't stop developing until about 25 years old.
102
Tigers can see 6 times better at night than humans.
305