Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
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In 1996, research found that having excessive body hair is linked to higher intelligence.
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If you are cold you are more likely to be hungry because you use energy to keep warm.
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The brain receives 20% of the body’s oxygen and 25% of total body glucose utilization, despite it accounting for only 2% of a person’s weight (about 1.4 kilograms).
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You can hear the blood flowing through your ears if you find a quiet place and cover them tightly.
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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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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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