The average sperm cell swims at 8 inches per hour.
4
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
A human brain produces as many as 12,000 to 50,000 thoughts per day, depending on how deep a thinker a person is.
23
The human brain is more active during sleep than during the day.
28
If the human eye was a digital camera, it would have 576 megapixels.
25
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Crying literally alleviates stress and uniquely allows humans to decrease feelings of anger and sadness.
24
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13