According to conclusions from three different groups of scientists who published in Nature in 2016, the DNA of Eurasians diverged from that of Africans 60,000 to 80,000 years ago. In other words, all humans alive today are descendants of H. sapiens who migrated out of Africa within that window—as well as other hominins, such as Neanderthals.
Stephen Ambrose on Mt. Toba global population crash
This new discovery adds to the picture that various Homo sapiens migration waves left Africa earlier than this, but were largely unsuccessful compared to the wave around 60,000 years ago. Their lines of descent must have eventually died out or were overprinted by later waves, as they have contributed little or nothing to our current genetic make-up.
“A prominent theory is that the few human survivors in Africa coped by developing more sophisticated social, symbolic and economic strategies, in turn enabling them to repopulate Africa and then migrate into Europe, Asia and Sahul by 60-50,000 years ago,” he said.
Archaeological evidence from Africa, India and Asia support the idea that the Toba eruption had minimal effects on humans and did not cause a population bottleneck.
“In fact, archaeological sites in southern Africa show human populations thrived following the Toba super-eruption,” Professor Clarkson said.
“Climate and vegetation records from Lake Malawi in East Africa likewise show no evidence for a volcanic winter at the time of the eruption.”
Genetic studies similarly have not detected a clear population bottleneck around 74,000 years ago.
“In Sumatra, close to the eruption itself, colleagues found Homo sapiens teeth which dated back to 73,000-63,000 years ago.
“This indicates Homo sapiens was living in Sumatra in a closed canopy rainforest environment soon after the eruption,” Professor Clarkson said.
Mount Toba in Indonesia erupted in spectacular fashion around 74,000 years ago, but the resulting fallout doesn't appear to have interfered with our ancient ancestors' efforts to colonise the world, according to Australian-led research. The scientists say tools found in Dhaba, India that date from 80,000 to 48,000 years ago provide a record of continuous populations that lived through the Mount Toba super eruption. The tools they found are similar to others found in Arabia which are between 100,000 and 47,000 years old, and in northern Australia, which are 65,000 years old. That suggests these diverse regions were linked by an early human dispersal out of Africa, and the dispersal was uninterrupted by the volcanic eruption, they say.
So this used to be the basis for tracking the spread of Modern Humans (homo sapiens) - no longer says Professor Christopher Clarkson et. al.
Modern human dispersal out of Africa, and more importantly east of Arabia, must therefore have taken place before ~65 ka
So does he stick to this claim in his latest paper?
https://www.sciencedaily.com/releases/2020/02/200218104709.htm
So here he states that modern humans were in Australia Before 65,000 years ago.
The oldest occupation layer at Madjedbebe also holds evidence for the oldest edge ground stone axes in the world, the earliest grindstone technology outside Africa, the early shaping of stone spearheads, many kilograms of ground ochre, and the first recorded use of reflective pigments in the world.
Application of the ecocultural range expansion model to modern human dispersals in Asia
1) lithic technologies in these Initial Upper Paleolithic (IUP) industries are generally known as an intermediate level between Middle Paleolithic (MP), including the Levallois core-reduction technology, and the fully Upper Paleolithic (UP) tool kits with abundant and ubiquitous bladelets, bone artifacts and ornaments - consistent with a prediction that the initial dispersal (first wave) is made without switching to high densities of skilled individuals and population. 2) DNA from a 37,000–42,000-year-old modern human from Romania shows a recent Neanderthal ancestry (Fu. et al., 2015). The evidence of introgression suggests that archaic and modern humans coexisted at a very early stage of dispersal and that the coexistence continued for a noticeable duration, being consistent with the predicted time delay between the first arrival of modern humans and the extinction of archaic humans. This idea is also consistent with the possibility of cultural contacts between IUP modern humans and Neanderthals, which gained support from a new fact that pendants from the IUP site of Bacho Kiro resemble those created by Neanderthals of the Châtelperronian layers at Grotte du Renne (Hublin et al., 2020).
So are these modern humans or archaic humans?
Recent genetic analyses point to a modern human exit from Africa around 70–52 ka37,38, in which all contemporary non-African peoples branched off from the same ancestral population that left Africa, possibly with minor genetic contributions from an earlier modern human migration wave37,39. Fossil evidence supports earlier dispersals of Homo sapiens, with our species present in Greece and the Levant by 200–185 ka40,41, Arabia by ~85 ka42, China before ~80 ka43 and Southeast Asia by 73–63 ka44, in association with MSA/Middle Palaeolithic technology (where stone artefacts are present). Recent finds from Madjedbebe in northern Australia also document a modern human presence at the eastern end of the ‘southern arc’ dispersal route by 65 ± 6 ka45, indicating that groups of Homo sapiens likely colonised South Asia prior to this time. The strong connections between Aboriginal and South Asian modern human genomes is consistent with dispersal through South Asia1,46,47,48 and admixture with Denisovans somewhere along this route49,50. The presence of centripetal core and retouched point technology—and the absence of microlithic technology—in northern Australia at c.65 ka makes connections to Southeast Asia, India and East Africa much stronger than previously proposed11,42. These technologies co-occur in sites east of Africa dated to between about 100 and 47 ka, suggesting they were likely stepping stones along the southern arc dispersal route11. This hypothesis is further supported by quantitative comparisons of core technologies from along this route that point to technological continuity between Africa and Australia10,11,31. Modern human dispersal out of Africa, and more importantly east of Arabia, must therefore have taken place before ~65 ka, so cultural and fossil evidence from sites dating to this period will be important for future tests of this hypothesis, notwithstanding the fact that population contractions and turnovers may have also occurred.
https://www.nature.com/articles/s41467-020-14668-4
Anatomically Modern Humans in China at 85,000 years ago.
OK so here is the definitive overview article.
https://www.sapiens.org/archaeology/early-human-migrations/
Will Asia Rewrite Human History?
Politics, geography, and tradition have long focused archaeological attention on the evolution of Homo sapiens in Europe and Africa. Now, new research is challenging old ideas by showing that early human migrations unfolded across Asia far earlier than previously known.
A new crop of discoveries, particularly from Asia, suggest that modern humans first left Africa some 200,000 years ago, taking multiple different routes.
https://www.nature.com/articles/s41598-018-19601-w
Early dispersals during Marine Isotope Stage 5 (MIS 5; 130–90 ka) may be inferred from 90–120 kyr fossils in the Levant8,9, 80–120 kyr human teeth from Fuyan Cave, China10, 73–63 kyr teeth from Sumatra11, a 63 kyr cranium from Tam Pa Ling, Laos12, from neurocranial shape diversity13, and from stone artefacts at Jebel Faya, U.A.E., dated to 95–127 ka14. However, most phylogenetic estimates from living Eurasian populations point to their origin from a single late exodus at around 80–40 ka15,16 initiating AMH expansion across south Asia to Australia by ~65 ka17, although the data do not preclude earlier migrations whose lineages are now extinct18.
.............
The new scientific dating evidence raises the possibility that modern humans interacted with other, now extinct, species of humans for tens of thousands of years. It also fits in with recent discoveries of remains and genetic studies that also indicate an earlier departure from Africa.
https://onlinelibrary.wiley.com/doi/full/10.1002/jqs.3137
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