Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Cats have a weak sense of taste. They have only 473 tastebuds, humans have 9,000.
307
On average, there's 100 billion neurons in the human brain.
83
Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
89
A man's beard grows fastest when he anticipates sex.
239
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
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