The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Your fingernails grow faster in summer.
744
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
The human eye blinks an average of 4,200,000 times a year.
233
In 30 minutes, the average body gives off enough heat (combined) to bring a half gallon of water to boil.
198
Human hair and fingernails continue to grow after death.
7
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
Our brains have a negativity bias and will remember bad memories more than good ones.
15