Your fingernails grow faster in summer.
744
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Yawns are more contagious among people with closer relationships.
163
Unconsciousness will occur after 8-10 seconds after loss of blood supply to the brain.
93
Early American humans hunted car-size armadillos and used their shells for houses.
12
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
If your DNA was stretched out it would reach to the moon 6,000 times.
256
The human brain is more active during sleep than during the day.
28