The ‘Out of Africa’ Theory
Page 1
https://www.youtube.com/watch?v=8183HPmA2_Ib
https://www.youtube.com/watch?v=CJdT6QcSbQ0
https://www.youtube.com/watch?v=B5orVEJburQ
The ‘Out Of Africa’ hypothesis or theory is that all modern humans came from a single group called Homo
sapiens that migrated out of Africa between 125,000 and 60,000 years ago. These humans spread throughout
Europe and Asia over thousands of years. The theory also proposes that when the sea levels were lower
during the ice ages, they used exposed ‘land bridges’; One land bridge to cross from northern Russia to
Canada and then down into North and South America, and another from New Guinea down to Australia.
Researchers have produced new DNA genetic evidence that supports the theory that all modern
humans have this common Homo sapiens ancestry.
When humans first left Africa, they followed the coasts, where resources were abundant. The first wave
moved across the Middle East, into southern Asia, and eventually all the way down to Australia. This
occurred roughly between 90,000 and 30,000 years ago. Additional waves of migration followed. Between
40,000 and 12,000 years ago, humans moved north into Europe.
The icy conditions at the time also helped expand early humanity's territory. Massive sheets of ice expanded
up over the land, causing the sea levels to drop. This formed a land bridge between Siberia and Alaska that
we call Beringia. The first humans crossed over 30,000 years ago, moving down the west coast of North
America. Humans eventually spread into South America and others pushed east into what is now the eastern
United States and Canada. This is supported by DNA genetic evidence and a similarity in the dental
structures of Siberian and North American populations of the era.
At the time of the migration, 50,000 years ago, Australia and New Guinea were joined by a land bridge and
the region was also only separated from the main Eurasian land mass by narrow straits such as Wallace's
Line in Indonesia. The land bridge was submerged about 8,000 years ago. This dispersal, from Africa to
Australia through Arabia, Asia and the Malay Peninsula, could have occurred at a rate of 1km per year.
The initial spread of humanity across the Earth was driven primarily by food and climate. Nomadic tribes of
up to a few dozen people likely followed the migration patterns of the herd animals they hunted. Climate
change opened new areas for hunting, even as technology such as mastery of fire and meat preserving
allowed humans to live in less-than-ideal conditions. The human ability to adapt to new circumstances also
facilitated global expansion and the spread of humans from out of Africa.
Modified from: http://www.sciencedaily.com/releases/2007/05/070509161829.htm
_________________________________________________
______
_________________________________________________
5. What motivated
the people to move
Out of Africa ?
____________________
www.interactive-learning.com.au
_______________
_______________________________
_______________________________
_______________
_______________
_______________________________
_______________________________
4. What evidence is used now to
show that the Out of Africa
hypothesis or theory is correct?
____________________
____________________
____________________
____________________
of the earth that are
now covered by ocean.
____________________
2. Fill in the map below. Draw in the lines and dates of human movement out of Africa. 3. Explain how the people at the time could travel across areas
____________________________________________________________________________________________________________________________
____________________________________________________________________________________________________________________________
1.What was the OUT OF AFRICA theory? (Try and use your own words) __________________________________________________________________
Page 2