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.
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One human hair can support 3 ounces.
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Your heart will pump about 212 million liters in its lifetime.
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Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
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An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
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The largest cell in the human body is the female egg and the smallest is the male sperm.
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Only 12,000 years ago there was a species closely related to modern humans called Homo floresiensis that had been living on an Indonesian Island. They used fire and rather advanced tools, yet were only about 3 feet tall and weighed around 25kg.
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