Human Migration

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  • Created by: Laura
  • Created on: 16-05-13 11:50

Climate change and human behaviour

  • 200,000 years ago first evolved in Africa
  • 60,000 years ago, spread out of Africa
  • 60,000 years ago glacial period caused water to lock up in ice and sea levels were much lower, making it easier to cross from Africa to Yemen
  • Then spread through Asia and Europe during the interglacial and adapted tools, clothing, home and equipment to suit enviroment
  • 25,000 years ago another cold period produced a land bridge between Siberia and North America.
  • Spread from Asia to North America
  • 11,000 years ago climate became more stable and first signs of people settling down and growing crops
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Mitochondrial DNA

  • Many mitochondrial in a cell - they have their own DNA
  • Only comes from Mother
  • Mutates faster than nuclear DNA
  • After death, DNA decays
  • Greater abundance of mtDNA as there is many mitochondria but only one nucleus
  • Greater chance that it will be in a good enough condition to identify genetic sequences
  • This helps in tracking evolutions using fossil material
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mtDNA detective work

  • Studies of mutations in mtDNA in people suggest that mtDNA evolved from a woman in Africa between 130000 and 200000 years ago
  • Mitochondrial Eve or African Eve
  • Doesn't mean she was the only woman living at the time
  • Only one with unbroken female-female line all the way down from her generation to ours

Can also show how closely related to others we are.

This suggests how humans spread out of Africa and populated the rest of the world.

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