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.
15
Your thumb is about the same size as your nose.
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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
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
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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 human being loses an average of 40 to 100 strands of hair a day.
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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
On average, there's 100 billion neurons in the human brain.
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