Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
It is possible for you to survive even after the removal of the spleen, the stomach, one kidney, one lung, 75% of the liver, 80% of the intestines, and almost every organ from the pelvic and groin area.
218
Yawns are more contagious among people with closer relationships.
163
It takes about 20 seconds for a red blood cell to circle the whole body.
102
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
Enamel is hardest substance in the human body.
61
A third of the human population sneezes when they look at the Sun. Light can signal the ocular nerve near the sinuses and triggers a sneeze.
18
Only humans shed emotional tears.
331