The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
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
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Early American humans hunted car-size armadillos and used their shells for houses.
12
When you kiss someone for the first time, you get a spike in the neurotransmitter dopamine, making you crave more.
23
Our brains have a negativity bias and will remember bad memories more than good ones.
15
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