Fossil homo sapiens skull in Greece puts paid to the single Out of Africa theory

There were many waves of homo sapiens Out of Africa from over 200,000 years ago.

I think the idea of a single Out of Africa, post-Toba wave is all but dead. Clearly there were pre-Toba and post-Toba migrations. It is highly likely that some migratory waves bred with archaic humans they came across and that there was interbreeding between newer migrants and older migrants.

An early dispersal of modern humans from Africa to Greece

Analysis of two fossils from a Greek cave has shed light on early hominins in Eurasia. One fossil is the earliest known specimen of Homo sapiens found outside Africa; the other is a Neanderthal who lived 40,000 years later.

Some key early fossils of Homo sapiens and related species in Africa and Eurasia. Harvati et al.5 present their analyses of two fossil skulls from Apidima Cave in Greece. They report that the fossil Apidima 1 is an H. sapiens specimen that is at least 210,000 years old, from a time when Neanderthals occupied many European sites. It is the earliest known example of H. sapiens in Europe, and is at least 160,000 years older than the next oldest H. sapiens fossils found in Europe6 (not shown). Harvati and colleagues confirm that, as previously reported7, Apidima 2 is a Neanderthal specimen, and they estimate that it is at least 170,000 years old. The authors’ findings, along with other discoveries of which a selection is shown here, shed light on the timing and locations of early successful and failed dispersals out of Africa of hominins (modern humans and other human relatives, such as Neanderthals and Denisovans). kyr, thousand years old.

The origin and early dispersal of Homo sapiens has long been a subject of both popular and scholarly interest1. It is almost universally agreed that H. sapiens (modern humans) evolved in Africa, with the earliest known fossil representatives of our species dated to around 315,000 years ago in Morocco (at a site called Jebel Irhoud)2 and approximately 260,000 years ago in South Africa (at Florisbad)3. Stone tools comparable to those found with both of these fossils have been excavated in Kenya (at Olorgesailie)4 and dated to about 320,000 years agoWriting in Nature, Harvati et al.5 describe their analysis of a fossil from Apidima Cave in southern Greece that they report to be an early modern H. sapiens at least 210,000 years old. This fossil is the oldest known modern human in Europe, and probably in all of Eurasia, and is more than 160,000 years older than the next oldest known European fossil of H. sapiens

Apidima Cave fossils provide earliest evidence of Homo sapiens in Eurasia

Abstract

Two fossilized human crania (Apidima 1 and Apidima 2) from Apidima Cave, southern Greece, were discovered in the late 1970s but have remained enigmatic owing to their incomplete nature, taphonomic distortion and lack of archaeological context and chronology. Here we virtually reconstruct both crania, provide detailed comparative descriptions and analyses, and date them using U-series radiometric methods. Apidima 2 dates to more than 170 thousand years ago and has a Neanderthal-like morphological pattern. By contrast, Apidima 1 dates to more than 210 thousand years ago and presents a mixture of modern human and primitive features. These results suggest that two late Middle Pleistocene human groups were present at this site—an early Homo sapiens population, followed by a Neanderthal population. Our findings support multiple dispersals of early modern humans out of Africa, and highlight the complex demographic processes that characterized Pleistocene human evolution and modern human presence in southeast Europe.


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Hominid genetics get more complex

More than a million years ago, ancestral hominids were present across most of Europe and Asia. Perhaps they had spread from Africa but that is not certain. They gave rise to Neanderthals, Denisovans, at least one unknown hominin species and also to homo sapiens. New research reported in Nature now shows that interbreeding took place – and probably were not just isolated events – between the various hominin species.

The genome of the offspring of a Neanderthal mother and a Denisovan father

Abstract

Neanderthals and Denisovans are extinct groups of hominins that separated from each other more than 390,000 years ago1,2. Here we present the genome of ‘Denisova 11’, a bone fragment from Denisova Cave (Russia)3 and show that it comes from an individual who had a Neanderthal mother and a Denisovan father. The father, whose genome bears traces of Neanderthal ancestry, came from a population related to a later Denisovan found in the cave4,5,6. The mother came from a population more closely related to Neanderthals who lived later in Europe2,7 than to an earlier Neanderthal found in Denisova Cave8, suggesting that migrations of Neanderthals between eastern and western Eurasia occurred sometime after 120,000 years ago. The finding of a first-generation Neanderthal–Denisovan offspring among the small number of archaic specimens sequenced to date suggests that mixing between Late Pleistocene hominin groups was common when they met.

Nature News writes:

A female who died around 90,000 years ago was half Neanderthal and half Denisovan, according to genome analysis of a bone discovered in a Siberian cave. This is the first time scientists have identified an ancient individual whose parents belonged to distinct human groups. The findings were published on 22 August in Nature. 

graphic Nature

Given the patterns of genetic variation in ancient and modern humans, scientists already knew that Denisovans and Neanderthals must have bred with each other — and with Homo sapiens. ……… Before the discovery of the Neanderthal–Denisovan individual, whom the team has affectionately named Denny, the best evidence for so close an association was found in the DNA of a Homo sapiens specimen who had a Neanderthal ancestor within the previous 4–6 generations.

A single Out-of-Africa source for all homo sapiens is looking less and less likely. There were probably multiple waves out of Africa  and many of the subsequent expansions probably came out of AfricArabia. It is very likely that as these “modern humans” spread, they met and interbred with their distant Neanderthal, Denisovan and other cousins. Possibly the Denisovans were mainly in what is now Central and east Asia and even eastern Siberia. Possibly the Neanderthals were spread from Central Asia to points west across Europe.

The human genetic story now goes back to times from which there is little or no archaeological record. It seems that some Neanderthals may well have had speech even if not any well developed language. The control of fire goes back some 400,000+ years ago. Stone tools were around from around 1.8 million years ago. Perhaps the beginnings of modern humans does not have to start so far back, but it does look like the story of homo sapiens now needs to be pushed backwards into time to at least the common hominin ancestor from around a million years ago.


 

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Bread from 14,400 years ago suggests a long transition to the Neolithic

The University of Copenhagen reports:

A team of researchers from the University of Copenhagen, University College London and University of Cambridge have analysed charred food remains from a 14,400-year-old Natufian hunter-gatherer site – a site known as Shubayqa 1 located in the Black Desert in northeastern Jordan. The results, which are published today in the journal Proceedings of the National Academy of Sciences, provide the earliest empirical evidence for the production of bread:

“The presence of hundreds of charred food remains in the fireplaces from Shubayqa 1 is an exceptional find, and it has given us the chance to characterize 14,000-year-old food practices. The 24 remains analysed in this study show that wild ancestors of domesticated cereals such as barley, einkorn, and oat had been ground, sieved and kneaded prior to cooking. The remains are very similar to unleavened flatbreads identified at several Neolithic and Roman sites in Europe and Turkey. So we now know that bread-like products were produced long before the development of farming. The next step is to evaluate if the production and consumption of bread influenced the emergence of plant cultivation and domestication at all,” said University of Copenhagen archaeobotanist Amaia Arranz Otaegui, who is the first author of the study.

…… The charred food remains were analysed with electronic microscopy at a University College London lab by PhD candidate Lara Gonzalez Carratero (UCL Institute of Archaeology), who is an expert on prehistoric bread:

“The identification of ‘bread’ or other cereal-based products in archaeology is not straightforward. There has been a tendency to simplify classification without really testing it against an identification criteria. We have established a new set of criteria to identify flat bread, dough and porridge like products in the archaeological record. Using Scanning Electron Microscopy we identified the microstructures and particles of each charred food remain,” said Gonzalez Carratero.

This would support the view that the transition from hunter-gatherers to settled agriculturalists was a long period which may well have started some 50,000 years ago and evolved through a form of transient agriculture. to eventually reach settled agriculture around 12-10,000 years ago.

And then came the cities.


 

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Aboriginals stagnated for 50,000 years as hunter-gatherers and missed the agricultural revolution

Australian Aboriginals are regarded in a very romantic light these days but the reality is that they are an example of a human population which, whether for cultural or genetic reasons or both, missed the agricultural revolution which swept the world between 10 and 15,000 years ago. They are an example of a human population which remained isolated for 50,000 years and which eked out a survival as hunter-gatherers and did not develop either cognitively or in technology. The colonisation which followed the rediscovery of Australia in 1606 (or 1592?) met no resistance from an indigenous population that was in any way capable of protecting their habitat. They were still hunter-gatherers then – and fairly backward hunter-gatherers at that.

How Did Aboriginal Australians Arrive on the Continent? DNA Helps Solve a Mystery

By Carl Zimmer, March 8, 2017

Human skeletons and archaeological remains in Australia can be traced back nearly 50,000 years before the trail disappears. Before then, apparently, Australia was free of humans. So how did people get there, and when? Where did humans first arrive on the continent, and how did they spread across the entire landmass?

Answers to some of these questions are stored in the DNA of Aboriginal Australians. A genetic study of 111 Aboriginal Australians, published on Wednesday, offers an interesting — and, in some respects, unexpected — view of their remarkable story. All living Aboriginal Australians descend from a single founding population that arrived about 50,000 years ago, the study shows. They swept around the continent, along the coasts, in a matter of centuries. And yet, for tens of thousands of years after, those populations remained isolated, rarely mixing.

The DNA used in the new study comes from aboriginal hair collected during a series of expeditions between 1926 and 1963. The Board for Anthropological Research at the University of Adelaide sent researchers to communities across Australia, where they collected vast amounts of information about aboriginal languages, ceremonies, artwork, cosmologies and genealogy.  …….

………… Fifty thousand years ago, sea levels were so low that Australia and New Guinea formed a single continent. Humans moved from Southeast Asia onto this landmass, some settling in what is now New Guinea, others traveling farther south into Australia.

They kept to the coastlines until they reached southern Australia 49,000 years ago. But once this great migration was finished, the new study suggests, the ancestors of today’s aborigines hunkered down in their new homes — for tens of thousands of years.

The mitochondrial DNA contains no evidence that these populations mixed in any significant way, ………… 

Farming explains the difference, Dr. Cooper suggests. Unlike Africa, Asia and Europe, Australia did not experience the rise of agriculture several thousand years ago. “If you don’t have cheap carbohydrates, you don’t increase in population size,” he said.

Populations grew on other continents, but they often risked catastrophic crop failure. When that happened, Dr. Cooper said, “there’s only one response — mass migration.” In Australia, however, aborigines did not depend on crops and lived as nomads in discrete regions. They never needed to move across the continent.

So the narrative is of ancient but anatomically modern humans arriving in Australia when sea levels were low, spreading around the coast, but then of becoming fairly sedentary local populations without much intercourse with each other, let alone with any non-Australian populations. They eked out a survival as hunter-gatherers. They had neither the impetus of cultural exchange or of any genetic exchange with other populations to instigate development. The agricultural revolution that swept the rest of the world never happened for them. Without access to carbohydrates the population never grew significantly. Language existed as did some pictorial representations but writing never took off. Without farming and its attendant population growth, settlements never developed to become towns or cities. There was no surplus to drive specialisation. There was no development of any significance for 50,000 years and there were no cultural or genetic impulses which could lead to development.

It may not be politically correct to say so but the reality is that before the colonisation by Europeans, the Australian Aboriginals were in a cultural and genetic dead-end.

image wikipedia



 

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The single Out-of-Africa theory is dying

A new paper shows that it is likely that modern humans had left Africa by at least 177,000 years ago. The single Out-of-Africa theory is dying if not completely dead. Certainly some of the earlier excursions out of Africa may not have survived. I am still sticking to my narrative of the peopling of the world being mainly due to (at least) two waves of expansion from AfricArabia; one before the Toba eruption (74,000 years ago) and one after.

Hershkovitz et al, The Earliest Modern Humans outside Africa, Science  26 Jan 2018: Vol. 359, Issue 6374, pp. 456-459, DOI: 10.1126/science.aap8369

Abstract: Recent paleoanthropological studies have suggested that modern humans migrated from Africa as early as the beginning of the Late Pleistocene, 120,000 years ago. Hershkovitz et al.now suggest that early modern humans were already present outside of Africa more than 55,000 years earlier (see the Perspective by Stringer and Galway-Witham). During excavations of sediments at Mount Carmel, Israel, they found a fossil of a mouth part, a left hemimaxilla, with almost complete dentition.

The sediments contain a series of well-defined hearths and a rich stone-based industry, as well as abundant animal remains. Analysis of the human remains, and dating of the site and the fossil itself, indicate a likely age of at least 177,000 years for the fossil—making it the oldest member of the Homo sapiens clade found outside Africa.

Dinekes summarises this succinctly on his blog.

The sensational discovery of modern humans in the Levant 177-194 thousand years ago should cause a rethink of the currently held Out-of-Africa orthodoxy.

By Out-of-Africa, I mean here the origin of anatomically modern humans, as opposed to the earlier origin of the genus Homo or the later origin of behaviorally fully modern humans.

Two main pieces of evidence supported the conventional OOA theory:

1. The observation that modern Eurasians possess a subset of the genetic variation of modern Africans.
2. The greater antiquity of AMH humans in the African rather than the Eurasian palaeoanthropological record.

Both these observations are in crisis.

1a. The oldest African fossil AMH is in North Africa (Morocco, Jebel Irhoud); modern genetic variation does not single out this region as a potential source of modern humans. In short, modern genetic variation has nothing to say about where AMH originated.
1b. Eurasians can no longer be seen as a subset of Africans, given that they possess genetic variation from Denisovans, a layer of ancestry earlier than all extant AMH. While it is still true that most Eurasian genetic material is a subset of that of modern Africans, it is also true that the deepest known lineage of humans is the Denisovan-Sima de los huesos, with no evidence for any deeper African lineage. Within humans as a whole, Africans possess a subset of Eurasian genetic variation.
2a. African priority received a boost by 0.1My by the redating of Jebel Irhoud last year. And, non-African AMH received a boost of 0.05My by the Hershkovitz et al. paper yesterday. A very short time ago, Ethiopia boasted the oldest AMH by 0.07My and now it’s tied with the Levant and beaten by Morocco. It’s a bit silly to argue for temporal priority based on the spotty and ever-shifting palaeoanthropological record.
2b. It is virtually untenable to consider the ~120,000 year old Shkul/Qafzeh hominins as a failed Out-of-Africa, since it now seems that they may have been descendants from the Mislya Cave population of >50,000 or even >100,000 years earlier.


 

Out of Africarabia


 

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The Peopling of Asia

It now looks increasingly likely that there were multiple migrations out of AfricArabia eastwards, starting from well before the Toba eruption (74,000 years ago). My narrative of the peopling of India containing both pre-Toba and post-Toba waves (see Out of Africarabia) is not so implausible.

Christopher J. Bae, Katerina Douka, Michael D. Petraglia. On the origin of modern humans: Asian perspectivesScience, 2017; 358 (6368): eaai9067 DOI: 10.1126/science.aai9067

Science 08 Dec 2017:
Vol. 358, Issue 6368, eaai9067

Abstract

The traditional “out of Africa” model, which posits a dispersal of modern Homo sapiens across Eurasia as a single wave at ~60,000 years ago and the subsequent replacement of all indigenous populations, is in need of revision. Recent discoveries from archaeology, hominin paleontology, geochronology, genetics, and paleoenvironmental studies have contributed to a better understanding of the Late Pleistocene record in Asia. Important findings highlighted here include growing evidence for multiple dispersals predating 60,000 years ago in regions such as southern and eastern Asia. Modern humans moving into Asia met Neandertals, Denisovans, mid-Pleistocene Homo, and possibly H. floresiensis, with some degree of interbreeding occurring. These early human dispersals, which left at least some genetic traces in modern populations, indicate that later replacements were not wholesale.

BACKGROUND

The earliest fossils of Homo sapiens are located in Africa and dated to the late Middle Pleistocene. At some point later, modern humans dispersed into Asia and reached the far-away locales of Europe, Australia, and eventually the Americas. Given that Neandertals, Denisovans, mid-Pleistocene Homo, and H. floresiensis were present in Asia before the appearance of modern humans, the timing and nature of the spread of modern humans across Eurasia continue to be subjects of intense debate. For instance, did modern humans replace the indigenous populations when moving into new regions? Alternatively, did population contact and interbreeding occur regularly? In terms of behavior, did technological innovations and symbolism facilitate dispersals of modern humans? For example, it is often assumed that only modern humans were capable of using watercraft and navigating to distant locations such as Australia and the Japanese archipelago—destinations that would not have been visible to the naked eye from the departure points, even during glacial stages when sea levels would have been much lower. Moreover, what role did major climatic fluctuations and environmental events (e.g., the Toba volcanic super-eruption) play in the dispersal of modern humans across Asia? Did extirpations of groups occur regularly, and did extinctions of populations take place? Questions such as these are paramount in understanding hominin evolution and Late Pleistocene Asian paleoanthropology.

ADVANCES

An increasing number of multidisciplinary field and laboratory projects focused on archaeological sites and fossil localities from different areas of Asia are producing important findings, allowing researchers to address key evolutionary questions that have long perplexed the field. For instance, technological advances have increased our ability to successfully collect ancient DNA from hominin fossils, providing proof that interbreeding occurred on a somewhat regular basis. New finds of H. sapiens fossils, with increasingly secure dating associations, are emerging in different areas of Asia, some seemingly from the first half of the Late Pleistocene. Cultural variability discerned from archaeological studies indicates that modern human behaviors did not simply spread across Asia in a time-transgressive pattern. This regional variation, which is particularly distinct in Southeast Asia, could be related at least in part to environmental and ecological variation (e.g., Palearctic versus Oriental biogeographic zones).

OUTLOOK

Recent findings from archaeology, hominin paleontology, geochronology, and genetics indicate that the strict “out of Africa” model, which posits that there was only a single dispersal into Eurasia at ~60,000 years ago, is in need of revision. In particular, a multiple-dispersal model, perhaps beginning at the advent of the Late Pleistocene, needs to be examined more closely. An increasingly robust record from Late Pleistocene Asian paleoanthropology is helping to build and establish new views about the origin and dispersal of modern humans.

 

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The case for pre-Toba peoples reaching Australia is strengthened

The Toba super-volcano eruption took place 74,000 years ago and wiped out humanity over a large region of SE Asia – but there were some survivors. The traditional, single, out-of-Africa narrative puts the expansion wave beginning after the Toba eruption. My preferred narrative is of multiple waves out of Africa and into Arabia long before the Toba eruption and the main post-Toba expansion being from Africarabia. This narrative then includes admixture and assimilation of survivors from pre-Toba waves of expansion who were found along the way. Peoples from pre-Toba expansions who had settled in SE Asia would probably not have survived the eruption. Some of the pre-Toba peoples survived in isolated areas of India and points west and were mainly assimilated by later post-Toba waves.

Toba fallout: from geology.gsapubs.org

The theory has been that it was post-Toba waves of humans which reached Australia around 40,000 years ago at the earliest. But evidence is emerging that humans were in Austalia at least 65,000 years ago. Distinctive stone tool assemblages including grinding stones, ground ochres, reflective additives and ground-edge hatchet heads have been found in Madjedbebe, a rock shelter in northern Australia and dated to 65,000 years ago (stratigraphic and optical dating).

That would suggest that the first human Australians came either directly from a pre-Toba expansion or post-Toba from peoples in SE Asia who had themselves oioginated from a pre-Toba expansion.

Clarkson, et al, Human occupation of northern Australia by 65,000 years ago, Nature 547, 306–310 (20 July 2017), doi:10.1038/nature22968

Abstract: The time of arrival of people in Australia is an unresolved question. It is relevant to debates about when modern humans first dispersed out of Africa and when their descendants incorporated genetic material from Neanderthals, Denisovans and possibly other hominins. Humans have also been implicated in the extinction of Australia’s megafauna. Here we report the results of new excavations conducted at Madjedbebe, a rock shelter in northern Australia. Artefacts in primary depositional context are concentrated in three dense bands, with the stratigraphic integrity of the deposit demonstrated by artefact refits and by optical dating and other analyses of the sediments. Human occupation began around 65,000 years ago, with a distinctive stone tool assemblage including grinding stones, ground ochres, reflective additives and ground-edge hatchet heads. This evidence sets a new minimum age for the arrival of humans in Australia, the dispersal of modern humans out of Africa, and the subsequent interactions of modern humans with Neanderthals and Denisovans.

My preferred narrative has at least three waves leaving Africarabia, starting perhaps around 120,000 years ago.


 

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