Out of Africa Hypothesis

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Ad Honorem
Sep 2010
3,732
USA
#12
Hello, here are a few recent studies surrounding Out of Africa hypothesis and competing models (Multi-regional and the more up-to-date "Partial Replacement"), that I gathered for anyone and everyone's reading pleasure. :)

Recent studies that may shape our current views on human evolution:


Partial Replacement Model
Published April 14, 2009: PNAS - Early modern human diversity suggests subdivided population structure and a complex out-of-Africa scenario

Out of Africa Model
Published April 22, 2010: PLoS One - Formulating a Historical and Demographic Model of Recent Human Evolution Based on Resequencing Data from Noncoding Regions

Modern Humans Left Africa Earlier than Thought
Published November 30, 2011: PLoS One - The Nubian Complex of Dhofar, Oman: An African Middle Stone Age Industry in Southern Arabia (this link jumps to "Discussion/Conclusions")

Newly Discovered Modern Humans
Published March 14, 2012: PLoS One - Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians

^ This last one covers the initial interpretation of the Chinese fossils recently found.

Enjoy!
 
Jun 2012
15
Greece
#13
Thank you a lot for your replay!

I don't have words to explain my feelings for your comment. You take my topic a step further by giving these information and the chance to the readers to have a crearly view about what it's happening with the recent studies on it! Every topic has many sides and our opinions should not to be stable on one thing but search it widely! :)
 
Sep 2011
37
Philadelphia
#14
The 'Out-of-Africa' theory proposes that 1.4 million years ago Homo erectus left Africa and spread throughout Europe and Asia. In Europe, Homo erectus evolved into the Neanderthals. In Asia, most Homo erectus stopped evolving - with the exception of a small group in the Indonesian archipelago that branched off to become Homo floresiensis (aka the Hobbit). Unlike most of the Homo erectus in Asia, which stagnated, the Homo erectus that stayed in Africa continued to evolve and eventually became Homo sapiens.

About 200,000 years ago, Homo sapiens left Africa. They spread throughout the globe and conquered or out-competed Neanderthals and Homo erectus. The last Neanderthal died out around 30,000 years ago. The last Homo erectus died out somewhere between 200,000 and 30,000 years ago. The last Hobbit is believed to have died out in a volcanic eruption around 10,000 years ago. After conquering Homo erectus in Indonesia, Homo sapiens moved to Australia. If Homo erectus had made it to Australia first, then they too would have been conquered.

In a nutshell, 200,000 years ago an African tribe, either through superior food gathering ability or open war, started the extinction of all hominin species living throughout Eurasia.

Supporting the Out-of-Africa theory is work by Allan Wilson who provided evidence in 1987 that all modern humans share a single female ancestor who lived in Africa approximately 200,000 years ago.

African Origins
Over 160,000 years ago modern humans-Home Sapiens-lived in Africa. The earliest known archaeological evidence of our mtDNA and Ychromosome ancestors is found in East Africa.

160,000~135,000
Four groups travelled as hunter-gatherers south to the Cape of Good Hope, south-west to the Congo Basin and west to the Ivory Coast, carrying the first generation of mtDNA genes types 'L1'

135,000~115,000
A group travelled across a green Sahara 125,000 years ago, through the open northern gate, up the Nile to the Levant.

115,000~90,000
The branch that reached the Lavant died out by 90,000 years ago. A global freeze-up turned this area and north Africa into extreme desert. This region was later reoccupied by Neanderthal Man.

90,000~85,000
85,000 years ago a group crossed the mouth of the Red Sea-The Gates of Grief-prior to travelling as beach-combers along the southern coast of the Arabian Peninsula toward India. All non-African people are are descended from this group.

85,000~75,000
From Sri Lanka they continued along the Indian Ocean coast to western Indonesia, then a landmass attached to Asia. Still following the coast they moved aroung Borneo to south China.

74,000 Mt Toba
Super-eruption of Mt Toba, Sumatra, causing a 6 year nuclear winter and instant 1000 year ice-age with a dramatic population crash, to less than 10,000 adults. Volcanic ash from the eruption up to 5m deep covered India and Pakistan.

74,000~65,000
Following the devastation of the Indian sub-continent, repopulation took place. Groups crossed by boat from Timor into Austalia and also from Borneo into New Guinea. There was intense cold in the Lower Pleniglacial in the north.

65,000~52,000
Dramatic warming of the climate 52,000 years ago meant groups were finally able to move north up the Fertile Crescent returning to the Levant. From there they moved into Europe via the Bosporus from 50,000 years ago.

52,000~45,000
Mini Ice Age. Aurignacian Upper Paleolithic culture moved from Turkey into Bulgaria, Europe. The new style of stone tools moved up the Danube into Hungary then Austria.

45,000~40,000
Groups from the east Asian coast moved west through the central Asia steppes towards northeast Asia. From Pakistan they moved into Central Asia, and from Indo-China through Tibet into the Qing-hai Plateau.

40,000~25,000
Central Asians moved west towards eastern Europe, north into the arctic Circle and joined East Asians to start the spread into north-east Eurasia. This period saw the birth of spectacular works of art, as in the Chauvet cave in France.

25,000~22,000
Ancestors of the Native Americans who crossed the Bering land bridge connecting Siberia to Alaska, either passed through the ice corridor reaching Meadowcroft before the LGM, or took the coastal route.

22,000~19,000
During the last Ice Age, Northern Europe, Asia and North America were de-populated, with isolated surviving groups locked in refuges. In North America the ice corridor closed and the coastal route froze.

19,000~15,000
The Last Glacial Maximum [LGM] 18,000 years ago. In North America, south of the ice, groups continued to develop diversity in language, culture, and genes as they crossed into South America. Australian rock art-Bradshaw Paintings.

15,000~12,500
Continued amelioration of the global climate. Coastal route recommenced. Monte Verde, Chile - human habitation; radio-carbon dating from 11,790 to 13,565 years ago. Simple stone tools such as flakes and cobbles were excavated.

12,000~10,000
Reoccupation Of North America 12,500 years ago from south of the ice going north. In the sub-Arctic 11,500 years ago people moved out from the Beringean refuge to become the Eskimo, Aleuts and Na-Dene speakers.

10,000~8,000
The final collapse of the Ice Age heralded the dawn of agriculture. The Sahara was grassland, as implied by the life-size giraffe petroglyphs in Niger. Recolonisation of Britain and Scandinavia.

Bradshaw Foundation

Interesting stuff...
 
#16
This is a great comment! I know about this Chinese challenge to ''out of africa'' theory. The discovery of an early human fossil in southern China may challenge the commonly held idea that modern humans originated out of Africa. Jin Changzhu and colleagues of the Institute of Vertebrate Palaeontology and Palaeoanthropology in Beijing, announced to Chinese media last week that they have uncovered a 110,000-year-old putative Homo sapiens jawbone from a cave in southern China's Guangxi province. So as you can see a new topic born ''Out of China Hypothesis''. I'm answering you according to some things I have been reading from the internet :)

But the main theory that Africa has the lead role in this topic still exists.

This replay refers to the ''Cachibatches''
The china hypothesis is already proven by the chinese that its not true. Communist propaganda has made them believe this just like christian propaganda did with europeans. But scientists in china have to acknoledge the truth. And they did.

[ame=http://www.youtube.com/watch?v=6ZF0JBb6Clo&list=PLE2D6921D705754E2&index=2&feature=plpp_video]Incredible Human Journey 2/5 Asia (BBC) - YouTube[/ame]
 
Jun 2012
15
Greece
#17
Thank you so much for the video!

You posted a very interesting video and very helpful to my topic :). I never believe in Chinese theory,but I thought, I should answer to the previous viewer from what I saw on the internet. A long lasting video with lot's of information that I didn't listen before!
 

Star

Ad Honorem
Sep 2010
3,732
USA
#19
What the China findings/evidence might suggest is that anatomically modern humans left Africa 200,000 years ago instead of 100,000. There are no 200,000 year old non-African fossils to support this, however.

It is more likely that this evidence lends supports the Partial Replacement Model over the two opposing ones (Out of Africa vs. Multiregional), and clarifies that our origins may lie somewhere in between the two models. The interpretation of this evidence suggests that modern Asians may have evolved from a very closely-related but different-looking homo erectus type ancestor that devloped in situ, rather than in Africa. Remember, paleoanthropologists are going off fossil evidence, not genetic, so they are comparing morphology: size, shape, mid-facial projection, brow ridge, etc. This morphological variation does not mean that hominine groups were completely isolated from one another. Mostly isolated, but obviously not 100% if these fossils are indeed anatomically moderns from 110,000 years ago. They were just isolated enough to streamline into a set of morphological features that were different from other recently-branching laterally-evolving erectus groups. Eastern region genotype remained identical to the erectus in the middle east and Africa over the 200,000 years in the east, but phenotype varied and took on a unique look. From the paper linked above:

Rather than a single out-of-Africa dispersal scenario, we suggest that early modern humans were already divided into different populations in Pleistocene Africa, after which there followed a complex migration pattern.
PRM theorizes that many small scattered late homo erectus-like, early modern human groups (lived during the early and middle Pleistocene) disbanded, joined others, and and emanated over Africa and parts of Asia at different times and in waves. They did not completely seal off contact during the epoch (c.1.8 million years ago to 130,000 years ago), and stayed in close enough proximity to share genes every few hundred or even thousand years (thus, genetic similarity is maintained) with other surviving groups.

No doubt beorna will correct me, if I have mispresented any consensus info above (about the Partial replacement theory), related to the China fossils.
 
Dec 2009
19,933
#20
Welcome to Historum, Eleni; excellent initial posts.
(Better late than never :eek: :eek: :eek:)


Strictly speaking, the recent African origin of modern humans (dubbed as Out of Africa) is well beyond hypothetical ("theory") status; it is already as close as any biological model can be to be considered as an established fact.

Essentially what is currently in discussion is how exactly (e.g. when & how many times) did mankind come out of Africa; the superb review included & linked in the first post fundamentally summarizes the current state of the art.