Yawns are more contagious among people with closer relationships.
163
The human body contains over a billion miles of DNA.
147
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
One human hair can support 3 ounces.
191
If your DNA was stretched out it would reach to the moon 6,000 times.
256
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
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118