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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A human being loses an average of 40 to 100 strands of hair a day.
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The average person's skin weighs twice as much as their brain.
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After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
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There are about 255 babies born worldwide every minute.
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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.
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You forget 90% of your dreams.
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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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