1. If the Universe began 13 years ago, then, at this moment…
the earth would have existed for about
five years [4.5 billion ys]
large organisms with many cells for
7 months [600 million ys]
the asteroid that killed the dinosaurs would have landed
3 weeks ago [67 million ys]
Hominids would have existed for just
3 days [c. 7 million ys]
our own species, Homo Sapiens, for
53 minutes [c. 200,000 ys]
agricultural societies would have existed for
5 minutes [c. 10,000 ys]
the entire recorded history of civilization for
3 minutes [c. 5,000 ys: that’s when most world history courses start!]
modern industrial societies (and modern Australia) for
6 seconds [c. 250 ys]
1st humans in space and on the moon I I
1 second [c. 50 ys]

2. Out of Africa Thesis and the “Peopling of the World”
Spread of Modern Humans around the Globe
Most scholars believe that modern humans originated in Africa and some of them began leaving Africa around 100,000 years ago.
Gradually they spread throughout Eurasia. From Eastern Asia, some crossed to the America during the last Ice Age