It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Mushrooms are more closely related to humans than they are to plants.
47
Modern humans first appeared about 200,000 years ago, but record keeping didn't begin until about 6,000 years ago. That means about 97% of human history is lost.
21
Having sex can make a woman look younger and more attractive due to the release of estrogen and collagen.
346
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Some monks can increase their body temperature so much they can dry soaking sheets in a freezing room!
31