The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
13
Enamel is hardest substance in the human body.
61
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
We forget why we have entered a room because passing through doors creates an ‘event boundary’ causing the brain to file away what we were just thinking about.
26
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Yawns are more contagious among people with closer relationships.
163
If your DNA was stretched out it would reach to the moon 6,000 times.
256
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127