It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Americans did not commonly use forks until after the Civil War.
82
A person will create enough saliva to fill two average size swimming pools during his lifetime.
191
The Japanese commonly put ketchup on their rice.
16
2% of Europeans lack the genes for smelly armpits.
6
On average, a human being will have sex more than 3,000 times and spend two weeks kissing in their lifetime.
161
If Earth's life was compressed into 1 year, then humans would have been around for only 2 seconds.
15