Wednesday, 11 January 2017

(134) Human migration

Basic Dimension 

Number Archive

Above we see the second dispersal out of Africa.

A second dispersal took place via the so-called Southern Route, either before[28] or after[11][12] the Toba event, which happened between 69,000 and 77,000 years ago.[28]This dispersal followed the southern coastline of Asia, crossing about 250 kilometres (155 mi) of sea, and colonized Australia by around 50,000 years ago. According to this theory, Europe was populated either by a migration out of India, which was repopulated from southeast Asia after the Toba-event (pre-Toba hypothesis), or by an early offshoot which settled the Near East and Europe (post-Toba hypothesis).[11][12]

[N.B. Their are a number of competing theories around the timeline of migration out of Africa.] 

Homo sapiens (200 ka; 1400cc)

In paleoanthropology, the recent African origin of modern humans, also called the "Out of Africa" theory (OOA), recent single-origin hypothesis (RSOH), replacement hypothesis or recent African origin model (RAO), is the dominant model of the geographic origin and early migration of anatomically modern humans (Homo sapiens), which proposes a single area of origin for modern humans. According to this model, modern humans evolved in Africa and started to disperse through the world roughly 50,000 to 100,000 years ago. Recent single origin of modern humans in East Africa was cited as the scientific consensus as of the mid-2000s.[1][2]

The major competing hypothesis of "recent single origin" has been the multiregional origin of modern humans, which envisions a wave of Homo sapiens migrating earlier from Africa and interbreeding with local Homo erectus populations in multiple regions of the globe.[3][4]

In the 2010s, the discovery of evidence of archaic admixture of modern humans outside of Africa with Neanderthals and Denisovans has complicated the picture.[5]As of 2011, it appears likely that there were two waves of migration out of Africa, the first taking place between 130,000–115,000 years ago via northern Africa,[6][7][8][9]which appears to have mostly died out or retreated (although there is some evidence of a presence of modern humans in China about 80,000 years ago),[10] and a second via the so-called Southern Route, following the southern coastline of Asia, which led to the lasting colonization of Eurasia and Australia by around 50,000 years ago. Europe was populated by an early offshoot which settled the Near East and Europe (post-Toba hypothesis).[11][12]


"Recent African origin," or Out of Africa II, refers to the migration of anatomically modern humans (Homo sapiens) out of Africa after their emergence at c. 300,000 to 200,000 years ago, in contrast to "Out of Africa I", the migration of archaic humans from Africa to Eurasia between roughly 1.8 to 0.5 million years ago.
Since the early 21st century, the picture of "recent single-origin" migrations has become significantly more complex, not just due to the discovery of modern-archaic admixture but also due to the increasing evidence that the "recent out-of-Africa" migration took place in a number of waves spread over a long time period. As of 2010, there were two main accepted dispersal route for the out-of-Africa migration of early anatomically modern humans: via the "Northern Route" (via Nile Valley and Sinai) and the "Southern Route" via the Bab al Mandab strait.[17]

  • Posth et al. (2017) suggest that early Homo sapiens, or "another species in Africa closely related to us," might have first migrated out of Africa around 270,000 years ago.[18]
  • Finds at Misliya cave, which include a partial jawbone with eight teeth have been dated to around 185,000 years ago. Layers dating from between 250,000 and 140,000 years ago in the same cave contained tools of the Levallois type which could put the date of the first migration even earlier if the tools can be associated with the modern human jawbone finds.[19][20]
  • An Eastward Dispersal from Northeast Africa to Arabia during 150–130 kya based on the finds at Jebel Faya dated to 127 kya (discovered in 2011).[4][5] Possibly related to this wave are the finds from Zhirendong cave, Southern China, dated to more than 100 kya.[17] Other evidence of modern human presence in China has been dated to 80,000 years ago.[10]
  • The most significant dispersal took place around 70,000 years ago via the so-called Southern Route, either before[21] or after[14][15] the Toba event, which happened between 69,000 and 77,000 years ago.[21] This dispersal followed the southern coastline of Asia, and reached Australia around 65,000-50,000 years ago. Western Asia was "re-occupied" by a different derivation from this wave around 50,000 years ago, and Europe was populated from Western Asia beginning around 43,000 years ago.[17]
  • Wells (2003) describes an additional wave of migration after the southern coastal route, namely a northern migration into Europe at circa 45,000 years ago.[note 3] This possibility is ruled out by Macaulay et al. (2005) and Posth et al. (2016), arguing for a single coastal dispersal, with an early offshoot into Europe.

Dating: pre-or post-Toba

The dating of the Southern Dispersal is a matter of dispute.[28] It may have happened either pre- or post-Toba, a catastrophic volcanic eruption that took place between 69,000 and 77,000 years ago at the site of present-day Lake Toba. Stone tools discovered below the layers of ash disposed in India may point to a pre-Toba dispersal, but the exact source of these tools is disputed.[28]

Map of the migration of modern humans out of Africa, based on mitochondrial DNA. Colored rings indicate thousand years before present.


Assumption 278: About 40.000 years ago Homo sapiens (mtDNA = L3N) returned from the Arabian Peninsula and Europe to North Africa, where they developed as Berbers or Imazighen.


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