MGSLG. (2020). Module 2 Unit 4

What is the “out of Africa” hypothesis?


Source: Wikipedia

This hypothesis states that modern Homo sapiens evolved in Africa about 200,000 years ago and migrated outwards to Europe and Asia, according to the Southern Dispersal theory. 

Most scientists agree that modern humans (Homo sapiens) evolved in Africa and spread outwards across the continents. 

The following lines of evidence have been used to support this hypothesis:

  • The oldest fossils of australopithecines/Homo habilis/bipedal organisms have been found in Africa
  • The oldest fossils of Homo erectus have been found in Africa
  • Analysis of mitochondrial DNA shows that the oldest female ancestors of humans are from Africa
  • Analysis of Y chromosome shows that the oldest male ancestors of humans are from Africa.


Fossil evidence:

  • Ardipithecus fossil were found in Africa ONLY, nowhere else in the world
  • Australopithecus fossils found in Africa only (Karabo, Littlefoot, Taung child and Mrs Ples)
  • Oldest fossils of australopithecines, Homo habilis and other bipedal organisms were found in Africa
  • Oldest fossils of Homo erectus were found in Africa, followed by Asia and the youngest fossils of Homo erectus were found in Europe.


Genetic evidence:

  • Analysis of mutations in mtDNA trace oldest female ancestor to East Africa.


THE PERFECT EXAMPLE OF EXPLAINING THE OUT OF AFRICA HYPOTHESIS: (NOV 2016 P2 ESSAY MEMO)

HYPOTHESIS

  • All modern humans /Homo sapiens originated in Africa and migrated to other parts of the world


FOSSIL EVIDENCE:

  • Fossils of Ardipithecus were found ONLY in Africa /Rift Valley/Ethiopia/South Africa
  • Fossils of Australopithecus were found ONLY in Africa /Rift Valley/Ethiopia/South Africa
  • The fossils of Homo habilis were ONLY found in Africa
  • The OLDEST fossils of Homo erectus were found in Africa
  • The OLDEST fossils of Homo sapiens were found in Africa.


GENETIC EVIDENCE:

  • Mitochondrial DNA is inherited only from the maternal lines
  • Analysis of mutations on this mitochondrial DNA
  • Shows that the oldest female ancestor were located in Africa and that all humans descended from her /mitochondrial Eve
  • The Y chromosome shows the paternal line.


CULTURAL EVIDENCE:

  • The OLDEST/most primitive artefacts (tools, cutlery, art etc.) were found in Africa.


BIPEDALISM:

The fossils of all three genera indicate that: The foramen magnums are located in a more forward position:

  • The pelvis is wider and shortened
  • The spine is S-shaped.


Last modified: Thursday, 25 March 2021, 8:17 AM