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
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
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Humans are capable of running 40 mph according to a study by bio-mechanical expert Dr. Matthew Bundle. Today's fastest man, Usain Bolt, has a top speed of 28 mph.
34
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
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Crying literally alleviates stress and uniquely allows humans to decrease feelings of anger and sadness.
24
The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Due to the angle at which the optic nerve enters the brain, staring at a blue surface during sex greatly increases the intensity of orgasms.
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