It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Fingers prune underwater not because of them absorbing the water or washing away the oil, but because of an evolutionary trait caused by the brain to enhance the grip of your fingers underwater.
24
You can't tickle yourself.
29
It is possible for you to survive even after the removal of the spleen, the stomach, one kidney, one lung, 75% of the liver, 80% of the intestines, and almost every organ from the pelvic and groin area.
218
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
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
Crying literally alleviates stress and uniquely allows humans to decrease feelings of anger and sadness.
24
A human being loses an average of 40 to 100 strands of hair a day.
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