Showing posts with label Paleolithic. Show all posts
Showing posts with label Paleolithic. Show all posts

April 21, 2017

Younger Dryas comet impact encoded in Göbekli Tepe?

Fascinating if true.

Mediterranean Archaeology and Archaeometry, Vol. 17, No 1, (2017), pp. 233-250


DECODING GÖBEKLI TEPE WITH ARCHAEOASTRONOMY: WHAT DOES THE FOX SAY? 

Martin B. Sweatman* and Dimitrios Tsikritsis

We have interpreted much of the symbolism of Göbekli Tepe in terms of astronomical events. By matching low-relief carvings on some of the pillars at Göbekli Tepe to star asterisms we find compelling evidence that the famous ‘Vulture Stone’ is a date stamp for 10950 BC ± 250 yrs, which corresponds closely to the proposed Younger Dryas event, estimated at 10890 BC. We also find evidence that a key function of Göbekli Tepe was to observe meteor showers and record cometary encounters. Indeed, the people of Göbekli Tepe appear to have had a special interest in the Taurid meteor stream, the same meteor stream that is proposed as responsible for the Younger-Dryas event. Is Göbekli Tepe the ‘smoking gun’ for the Younger-Dryas cometary encounter, and hence for coherent catastrophism?

Link (pdf)

June 27, 2016

37,000 year old skull from Malaysia related to indigenous people of Borneo

Front. Ecol. Evol., 27 June 2016 | http://dx.doi.org/10.3389/fevo.2016.00075

Deep Skull from Niah Cave and the Pleistocene Peopling of Southeast Asia

Darren Curnoe et al.

The Deep Skull from Niah Cave in Sarawak (Malaysia) is the oldest anatomically modern human recovered from island Southeast Asia. For more than 50 years its relevance to tracing the prehistory of the region has been controversial. The most widely held view, originating with Brothwell's 1960 description and analysis, is that the Niah individual is related to Indigenous Australians. Here we undertake a new assessment of the Deep Skull and consider its bearing on this question. In doing so, we provide a new and comprehensive description of the cranium including a reassessment of its ontogenetic age, sex, morphology, and affinities. We conclude that this individual was most likely to have been of advanced age and female, rather than an adolescent male as originally proposed. The morphological evidence strongly suggests that the Deep Skull samples the earliest modern humans to have settled Borneo, most likely originating on mainland East Asia. We also show that the affinities of the specimen are most likely to be with the contemporary indigenous people of Borneo, although, similarities to the population sometimes referred to as Philippine Negritos cannot be excluded. Finally, our research suggests that the widely supported “two-layer” hypothesis for the Pleistocene peopling of East/Southeast Asia is unlikely to apply to the earliest inhabitants of Borneo, in-line with the picture emerging from genetic studies of the contemporary people from the region.

Link

May 19, 2016

35,000 year old mtDNA haplogroup U6 from Romania

I wouldn't be very surprised if many of the markers supposedly signifying recent gene flow Africa and Eurasia were actually quite old in Eurasia. The trouble is that reports of such gene flow were often based on simply observing that marker "X" occurs at a higher frequency in Africa than in Eurasia, so a common sense explanation is that it reflects limited recent gene flow between the continents. But, it is now known that common sense is not always the best guide, as e.g., ancient Europeans had mtDNA haplogroup M (in the past considered evidence of Asian admixture), Y-chromosome haplogroup C (ditto), and now U6.

The same should also apply to the Middle East where there has been admixture with Africans since the Islamic period at least. The existence of such admixture does not mean that every single lineage that occurs at low frequency in the Middle East and high frequency in Africa is diagnostic of this later period of admixture. Some of them could well be relics of old Middle Eastern populations. Who knows what people inhabited the presently inhospitable landscape of the Saharan-Arabian desert zone? The living populations can certainly make no claim to being the first ones there, but the genetic heritage of those earlier occupants may still persist in them in traces.

Similarly for the New World; in that case, there is a better case that European-looking lineages are indeed due to the colonization of the Americas over the last five centuries. However, that does not mean that all of them are, and we should be mindful of the possibility of pre-Columbian contact between the Old and New worlds.

Scientific Reports 6, Article number: 25501 (2016)

The mitogenome of a 35,000-year-old Homo sapiens from Europe supports a Palaeolithic back-migration to Africa

M. Hervella et al.

After the dispersal of modern humans (Homo sapiens) Out of Africa, hominins with a similar morphology to that of present-day humans initiated the gradual demographic expansion into Eurasia. The mitogenome (33-fold coverage) of the Peştera Muierii 1 individual (PM1) from Romania (35 ky cal BP) we present in this article corresponds fully to Homo sapiens, whilst exhibiting a mosaic of morphological features related to both modern humans and Neandertals. We have identified the PM1 mitogenome as a basal haplogroup U6*, not previously found in any ancient or present-day humans. The derived U6 haplotypes are predominantly found in present-day North-Western African populations. Concomitantly, those found in Europe have been attributed to recent gene-flow from North Africa. The presence of the basal haplogroup U6* in South East Europe (Romania) at 35 ky BP confirms a Eurasian origin of the U6 mitochondrial lineage. Consequently, we propose that the PM1 lineage is an offshoot to South East Europe that can be traced to the Early Upper Paleolithic back migration from Western Asia to North Africa, during which the U6 lineage diversified, until the emergence of the present-day U6 African lineages.

Link

May 02, 2016

Neandertal ancestry, going, going, ..., gone (?)

A deluge of new data from Upper Paleolithic Europe will give us all a lot to think about. It is incredible that Neandertal ancestry seems to have decreased over time in Europe (Oase1 is off-cline with lots of extra Neandertal ancestry from a recent genealogical Neandertal in the family tree). The functional form of the decrease seems pretty well approximated as linear.

The authors write:
Using one statistic, we estimate a decline from 4.3–5.7% from a time shortly after introgression to 1.1–2.2% in Eurasians today (Fig. 2).
This is remarkable because it shows  that most of the Neandertal ancestry of the earliest AMH in Europe was gone by the Mesolithic. It really seems that Neandertal genes were bred out of the gene pool over time. Will this trend continue into the future? Perhaps only minute traces of Neandertal DNA will remain in humans in 10,000 more years. Some of Neandertal DNA may yet prove to be neutral or beneficial, so at the limit the percentage may be more than zero. Nonetheless, the historical trend does suggest that modern humans inherited mostly genetic garbage from Neandertals and evolution is more than halfway through the process of getting rid of it.

As a corollary, there may have been other episodes of archaic admixture that are no longer detectable. Perhaps our modern human lineage has repeatedly admixed with other species, but traces of those admixtures are long gone by the action of natural selection. The reason for our relative homogeneity as a species may not be that we avoided intermixing with others, but that, sadly, most others had not much that was beneficial to offer to our ancestors.

Nature (2016) doi:10.1038/nature17993

The genetic history of Ice Age Europe

Qiaomei Fu et al.

Modern humans arrived in Europe ~45,000 years ago, but little is known about their genetic composition before the start of farming ~8,500 years ago. Here we analyse genome-wide data from 51 Eurasians from ~45,000–7,000 years ago. Over this time, the proportion of Neanderthal DNA decreased from 3–6% to around 2%, consistent with natural selection against Neanderthal variants in modern humans. Whereas there is no evidence of the earliest modern humans in Europe contributing to the genetic composition of present-day Europeans, all individuals between ~37,000 and ~14,000 years ago descended from a single founder population which forms part of the ancestry of present-day Europeans. An ~35,000-year-old individual from northwest Europe represents an early branch of this founder population which was then displaced across a broad region, before reappearing in southwest Europe at the height of the last Ice Age ~19,000 years ago. During the major warming period after ~14,000 years ago, a genetic component related to present-day Near Easterners became widespread in Europe. These results document how population turnover and migration have been recurring themes of European prehistory.

Link

April 14, 2016

Periods of human activity in Chauvet-Pont d'Arc cave

PNAS DOI: doi: 10.1073/pnas.1523158113

A high-precision chronological model for the decorated Upper Paleolithic cave of Chauvet-Pont d’Arc, Ardèche, France

Anita Quiles et al.

Radiocarbon dates for the ancient drawings in the Chauvet-Pont d’Arc Cave revealed ages much older than expected. These early ages and nature of this Paleolithic art make this United Nations Educational, Scientific and Cultural Organization (UNESCO) site indisputably unique. A large, multidisciplinary dating program has recently mapped the anthropological evolution associated with the cave. More than 350 dates (by 14C, U-Th, TL and 36Cl) were obtained over the last 15 y. They include 259 radiocarbon dates, mainly related to the rock art and human activity in the cave. We present here more than 80 previously unpublished dates. All of the dates were integrated into a high-precision Bayesian model based on archaeological evidence to securely reconstruct the complete history of the Chauvet-Pont d’Arc Cave on an absolute timescale. It shows that there were two distinct periods of human activity in the cave, one from 37 to 33,500 y ago, and the other from 31 to 28,000 y ago. Cave bears also took refuge in the cave until 33,000 y ago.

Link

April 10, 2016

Nubian assemblages from the Negev

Nubian assemblages from the Levant are quite important because they provide an intermediate link (along land routes) between those from Africa and Arabia. It's also more difficult now to consider the Arabian finds as a limited event without broader implications about modern human dispersals. From the paper:
Mapping the earliest dated sites that contain a Nubian component does not permit an unequivocal identification of a region of origin for the Nubian Technology.
Quaternary International doi:10.1016/j.quaint.2016.02.008

“Diffusion with modifications”: Nubian assemblages in the central Negev highlands of Israel and their implications for Middle Paleolithic inter-regional interactions

Mae Goder-Goldberger, Natalia Gubenko, Erella Hovers

Nubian Levallois cores, now known from sites in eastern Africa, the Nile Valley and Arabia, have been used as a material culture marker for Upper Pleistocene dispersals of hominins out of Africa. The Levantine corridor, being the only land route connecting Africa to Eurasia, has been viewed as a possible dispersal route. We report here on lithic assemblages from the Negev highlands of Israel that contain both Levallois centripetal and Nubian-type cores. Wetter conditions over the Sahara and Negev deserts during MIS 6a–5e provided a generally continuous environmental corridor into the Levant that enabled the dispersal of hominin groups bearing the Nubian variant of prepared core technologies. The Negev assemblages draw renewed attention to the place of the Levant as one of the dispersal routes out of Africa during the Late Pleistocene and could suggest that processes of human dispersals and cultural diffusion resulted in the spread of Nubian technology across eastern Africa, the western Sahara and the Nile Valley, the southern Levant and Arabia.

Link

January 16, 2016

Humans in the central Siberian Arctic ~45,000 years ago

The lack of such northerly sites prior to 45,000 years ago makes it quite likely that this mammoth kill was made by modern humans (it would be quite a coincidence if it was made by Neandertals at the same time as the expansionary Homo sapiens make their appearance all over the rest of Eurasia). If this is right, it's quite remarkable that by the mid to late 40,000s, modern humans were at ease from the equator to the arctic and from Europe to the remotest parts of Asia.

Science 15 Jan 2016:
Vol. 351, Issue 6270, pp. 260-263

Early human presence in the Arctic: Evidence from 45,000-year-old mammoth remains

Vladimir V. Pitulko, Alexei N. Tikhonov et al.

Archaeological evidence for human dispersal through northern Eurasia before 40,000 years ago is rare. In west Siberia, the northernmost find of that age is located at 57°N. Elsewhere, the earliest presence of humans in the Arctic is commonly thought to be circa 35,000 to 30,000 years before the present. A mammoth kill site in the central Siberian Arctic, dated to 45,000 years before the present, expands the populated area to almost 72°N. The advancement of mammoth hunting probably allowed people to survive and spread widely across northernmost Arctic Siberia.

Link

December 18, 2015

Archaic femur from Maludong, China

PLoS ONE 10(12): e0143332. doi:10.1371/journal.pone.0143332

A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China

Darren Curnoe et al.

The number of Late Pleistocene hominin species and the timing of their extinction are issues receiving renewed attention following genomic evidence for interbreeding between the ancestors of some living humans and archaic taxa. Yet, major gaps in the fossil record and uncertainties surrounding the age of key fossils have meant that these questions remain poorly understood. Here we describe and compare a highly unusual femur from Late Pleistocene sediments at Maludong (Yunnan), Southwest China, recovered along with cranial remains that exhibit a mixture of anatomically modern human and archaic traits. Our studies show that the Maludong femur has affinities to archaic hominins, especially Lower Pleistocene femora. However, the scarcity of later Middle and Late Pleistocene archaic remains in East Asia makes an assessment of systematically relevant character states difficult, warranting caution in assigning the specimen to a species at this time. The Maludong fossil probably samples an archaic population that survived until around 14,000 years ago in the biogeographically complex region of Southwest China.

Link

November 18, 2015

Two more Denisovans (Sawyer, Renaud et al. 2015)

PNAS doi: 10.1073/pnas.1519905112

Nuclear and mitochondrial DNA sequences from two Denisovan individuals

Susanna Sawyer, Gabriel Renaud et al.

Denisovans, a sister group of Neandertals, have been described on the basis of a nuclear genome sequence from a finger phalanx (Denisova 3) found in Denisova Cave in the Altai Mountains. The only other Denisovan specimen described to date is a molar (Denisova 4) found at the same site. This tooth carries a mtDNA sequence similar to that of Denisova 3. Here we present nuclear DNA sequences from Denisova 4 and a morphological description, as well as mitochondrial and nuclear DNA sequence data, from another molar (Denisova 8) found in Denisova Cave in 2010. This new molar is similar to Denisova 4 in being very large and lacking traits typical of Neandertals and modern humans. Nuclear DNA sequences from the two molars form a clade with Denisova 3. The mtDNA of Denisova 8 is more diverged and has accumulated fewer substitutions than the mtDNAs of the other two specimens, suggesting Denisovans were present in the region over an extended period. The nuclear DNA sequence diversity among the three Denisovans is comparable to that among six Neandertals, but lower than that among present-day humans.

Link

June 24, 2015

Oase1 had a Neandertal ancestor no earlier than ~200 years before his time

Several important conclusions of the discovery that Oase1 had a Neandertal ancestor 4-6 generations before his time (37-42 thousand years ago):
  • This is a smoking gun that modern humans interbred with Neandertals, following up on the publication of the Ust'Ishim and Kostenki-14 genomes; these two had longer Neandertal chunks than modern humans, from which it was estimated that their Neandertal admixture happened more than 50,000 years ago, roughly what one gets when looking at Neandertal chunks in modern humans alone. The Oase1 has even longer Neandertal chunks, and Neandertal admixture happened in its very recent past. 
  • So, it seems that Neandertal admixture was not a one-off event but is bracketed at least by the period 50-40 thousand years ago and happened in at least two places: Europe and the Near East.
  • The fact that the earliest European sample (N=1) has a recent Neandertal ancestor indicates that Neandertal admixture in the earliest Europeans cannot have been extremely rare or non-existent; if it were, the chances of finding one with the first try would be extremely low.
  • It is unlikely that Neandertals were killed off by modern humans immediately after the arrival of the latter in Europe, as the Oase1 is dated well after the arrival of modern humans to Europe.
  • Modern Europeans don't seem to be particularly related to the population of Oase1. After one substracts contamination and Neandertal admixture, what is left over is actually closer to East Asians than modern Europeans. But, it's equally close to East Asians and European hunter-gatherers. This can be explained if modern Europeans have ancestry from the mysterious "Basal Eurasians" via the Neolithic farmers.
Why did the Neandertals (and the significantly-Neandertal admixed AMH like Oase1) disappear? My bet is on the Campanian Ignibrite eruption.

Nature (2015) doi:10.1038/nature14558

An early modern human from Romania with a recent Neanderthal ancestor

Qiaomei Fu, Mateja Hajdinjak, Oana Teodora Moldovan, Silviu Constantin, Swapan Mallick, Pontus Skoglund, Nick Patterson, Nadin Rohland, Iosif Lazaridis, Birgit Nickel, Bence Viola, Kay Prüfer, Matthias Meyer, Janet Kelso, David Reich & Svante Pääbo

Neanderthals are thought to have disappeared in Europe approximately 39,000–41,000 years ago but they have contributed 1–3% of the DNA of present-day people in Eurasia1. Here we analyse DNA from a 37,000–42,000-year-old2 modern human from Peştera cu Oase, Romania. Although the specimen contains small amounts of human DNA, we use an enrichment strategy to isolate sites that are informative about its relationship to Neanderthals and present-day humans. We find that on the order of 6–9% of the genome of the Oase individual is derived from Neanderthals, more than any other modern human sequenced to date. Three chromosomal segments of Neanderthal ancestry are over 50 centimorgans in size, indicating that this individual had a Neanderthal ancestor as recently as four to six generations back. However, the Oase individual does not share more alleles with later Europeans than with East Asians, suggesting that the Oase population did not contribute substantially to later humans in Europe.

Link

May 13, 2015

Neandertal in the (immediate) family tree

Early European may have had Neanderthal great-great-grandparent
One of Europe’s earliest known humans had a close Neanderthal ancestor: perhaps as close as a great-great-grandparent.

The finding, announced on 8 May at the Biology of Genomes meeting in Cold Spring Harbor, New York, questions the idea that humans and Neanderthals interbred only in the Middle East, more than 50,000 years ago.

Qiaomei Fu, a palaeogenomicist at Harvard Medical School in Boston, Massachusetts, told the meeting how she and her colleagues had sequenced DNA from a 40,000-year-old jawbone that represents some of the earliest modern-human remains in Europe. They estimate that 5–11% of the bone's genome is Neanderthal, including large chunks of several chromosomes. (The genetic analysis also shows that the individual was a man). By analysing how lengths of DNA inherited from any one ancestor shorten with each generation, the team estimated that the man had a Neanderthal ancestor in the previous 4–6 generations. (The researchers declined to comment on the work because it has not yet been published in a journal).

October 22, 2014

High coverage genome from 45,000-year old Siberian (Ust'-Ishim)

This is the oldest full genome of a modern human published to date and it also comes from a time (45 thousand years ago) that coincides with the Upper Paleolithic revolution in Eurasia.

45 thousand years ago is probably close to when Eurasians started diverging from each other as they spread in all directions. So, we expect that a human from that time would be "undifferentiated Eurasian" and indeed this seems to be the case.

First the Y-chromosome:
The Y chromosome sequence of the Ust’-Ishim individual is similarly inferred to be ancestral to a group of related Y chromosomes (haplogroup K(xLT)) that occurs across Eurasia today6 (Supplementary Information section 9).
and mtDNA:
The Ust’-Ishim mtDNA sequence falls at the root of a large group of related mtDNAs (the ‘R haplogroup’), which occurs today across Eurasia (Supplementary Information section 8).
It is clear that this was a Eurasian individual:
Based on genotyping data for 87 African and 108 non-African individuals (Supplementary Information section 11), the Ust’-Ishim genome shares more alleles with non-Africans than with sub-Saharan Africans (|Z| = 41–89), consistent with the principal component analysis, mtDNA and Y chromosome results.
It was also more like East Asians than Europeans:
Among the non-Africans, the Ust’-Ishim genome shares more derived alleles with present-day people from East Asia than with present-day Europeans (|Z| = 2.1–6.4).
But, when they compared East Asians with La Brana and MA-1 they didn't see a difference:
However, when an ~8,000-year-old genome from western Europe (La Braña)9 or a 24,000-year-old genome from Siberia (Mal’ta 1)10 were analysed, there is no evidence that the Ust’-Ishim genome shares more derived alleles with present-day East Asians than with these prehistoric individuals (|Z| < 2). This suggests that the population to which the Ust’-Ishim individual belonged diverged from the ancestors of present-day West Eurasian and East Eurasian populations before—or simultaneously with—their divergence from each other. The finding that the Ust’-Ishim individual is equally closely related to present-day Asians and to 8,000- to 24,000-year-old individuals from western Eurasia, but not to present-day Europeans, is compatible with the hypothesis that present-day Europeans derive some of their ancestry from a population that did not participate in the initial dispersals of modern humans into Europe and Asia11.
So it seems that the Ust'-Ishim individual belonged to the same branch as Asians and WHG/ANE and modern Europeans are less like it because they also have "Basal Eurasian" admixture which they inherited via the EEF in the model of Lazaridis et al.

The authors could also get estimates of the mutation rate because this is a 45,000 year old individual that hasn't experienced 45,000 years worth of mutations:
Assuming that this corresponds to the number of mutations that have accumulated over around 45,000 years, we estimate a mutation rate of 0.43 × 10−9 per site per year (95% CI 0.38 × 10−9 to 0.49 × 10−9) that is consistent across all non-African genomes regardless of their coverage (Supplementary Information section 14). This overall rate, as well as the relative rates inferred for different mutational classes (transversions, non-CpG transitions, and CpG transitions), is similar to the rate observed for de novo estimates from human pedigrees (~0.5 × 10−9 per site per year14, 15) and to the direct estimate of branch shortening (Supplementary Information section 10). As discussed elsewhere14, 16, 17, these rates are slower than those estimated using calibrations based on the fossil record and thus suggest older dates for the splits of modern human and archaic populations.
This is a very direct confirmation of the "slow" autosomal rate of ~1.2x10-8 mutations/generation/bp using a technology much different than those used before to estimate this. The slower mutation rate implies that major splits in human history (such as the Out-of-Africa event) took place much earlier than the Upper Paleolithic revolution and the spread of humans across Eurasia. Modern humans probably established an early presence in the Levant/Arabia (consistent with Out-of-Arabia), and invented the Upper Paleolithic-related tools/behaviors there much later, and only then spread across Eurasia.

The authors write:
we estimate that the admixture between the ancestors of the Ust’-Ishim individual and Neanderthals occurred approximately 50,000 to 60,000 years BP, which is close to the time of the major expansion of modern humans out of Africa and the Middle East.
This clinches the hypothesis of Neandertal introgression in Eurasians, as Ust'-Ishim has longer Neandertal segments than modern humans, as one might expect from an individual who experienced this admixture more recently in its evolutionary past than modern humans did. It's probably in the Middle East that the Levantine/Arabian modern humans that expanded Out-of-Africa more than 100 thousand years ago came into contact with Neandertals, admixed with them and later carried this ancestry to the rest of Eurasia. I tend to think that the AMH "colony" was first limited to Arabia and only later (post-70kya) expanded north as the climate deteriorated there. The authors estimate the common ancestor of non-African Y-chromosomes (including E, which is probably a back-migration to Africa) to around 70 thousand years ago which may coincide with the Arabian Exodus event.

Nature 514, 445–449 (23 October 2014) doi:10.1038/nature13810

Genome sequence of a 45,000-year-old modern human from western Siberia

Qiaomei Fu et al.

We present the high-quality genome sequence of a ~45,000-year-old modern human male from Siberia. This individual derives from a population that lived before—or simultaneously with—the separation of the populations in western and eastern Eurasia and carries a similar amount of Neanderthal ancestry as present-day Eurasians. However, the genomic segments of Neanderthal ancestry are substantially longer than those observed in present-day individuals, indicating that Neanderthal gene flow into the ancestors of this individual occurred 7,000–13,000 years before he lived. We estimate an autosomal mutation rate of 0.4 × 10−9 to 0.6 × 10−9 per site per year, a Y chromosomal mutation rate of 0.7 × 10−9 to 0.9 × 10−9 per site per year based on the additional substitutions that have occurred in present-day non-Africans compared to this genome, and a mitochondrial mutation rate of 1.8 × 10−8 to 3.2 × 10−8 per site per year based on the age of the bone.

Link

October 09, 2014

~40 thousand year old cave art from Indonesia

The BBC website has some nice pictures of it.

Nature 514, 223–227 (09 October 2014) doi:10.1038/nature13422

Pleistocene cave art from Sulawesi, Indonesia

M. Aubert et al.

Archaeologists have long been puzzled by the appearance in Europe ~40–35 thousand years (kyr) ago of a rich corpus of sophisticated artworks, including parietal art (that is, paintings, drawings and engravings on immobile rock surfaces)1, 2 and portable art (for example, carved figurines)3, 4, and the absence or scarcity of equivalent, well-dated evidence elsewhere, especially along early human migration routes in South Asia and the Far East, including Wallacea and Australia5, 6, 7, 8, where modern humans (Homo sapiens) were established by 50 kyr ago9, 10. Here, using uranium-series dating of coralloid speleothems directly associated with 12 human hand stencils and two figurative animal depictions from seven cave sites in the Maros karsts of Sulawesi, we show that rock art traditions on this Indonesian island are at least compatible in age with the oldest European art11. The earliest dated image from Maros, with a minimum age of 39.9 kyr, is now the oldest known hand stencil in the world. In addition, a painting of a babirusa (‘pig-deer’) made at least 35.4 kyr ago is among the earliest dated figurative depictions worldwide, if not the earliest one. Among the implications, it can now be demonstrated that humans were producing rock art by ~40 kyr ago at opposite ends of the Pleistocene Eurasian world.

Link

September 28, 2014

43,500-year old Aurignacian north of the Alps

PNAS doi: 10.1073/pnas.1412201111

Early modern human settlement of Europe north of the Alps occurred 43,500 years ago in a cold steppe-type environment

Philip R. Nigst et al.

The first settlement of Europe by modern humans is thought to have occurred between 50,000 and 40,000 calendar years ago (cal B.P.). In Europe, modern human remains of this time period are scarce and often are not associated with archaeology or originate from old excavations with no contextual information. Hence, the behavior of the first modern humans in Europe is still unknown. Aurignacian assemblages—demonstrably made by modern humans—are commonly used as proxies for the presence of fully behaviorally and anatomically modern humans. The site of Willendorf II (Austria) is well known for its Early Upper Paleolithic horizons, which are among the oldest in Europe. However, their age and attribution to the Aurignacian remain an issue of debate. Here, we show that archaeological horizon 3 (AH 3) consists of faunal remains and Early Aurignacian lithic artifacts. By using stratigraphic, paleoenvironmental, and chronological data, AH 3 is ascribed to the onset of Greenland Interstadial 11, around 43,500 cal B.P., and thus is older than any other Aurignacian assemblage. Furthermore, the AH 3 assemblage overlaps with the latest directly radiocarbon-dated Neanderthal remains, suggesting that Neanderthal and modern human presence overlapped in Europe for some millennia, possibly at rather close geographical range. Most importantly, for the first time to our knowledge, we have a high-resolution environmental context for an Early Aurignacian site in Central Europe, demonstrating an early appearance of behaviorally modern humans in a medium-cold steppe-type environment with some boreal trees along valleys around 43,500 cal B.P.

Link

Levallois technology in Nor Geghi 1, Armenia

From the paper:
Empirical evidence supports the contention that Levallois technology is an inherent property of the Acheulian that evolves out of the existing, but previously separate technological systems of façonnage and débitage (7, 35), and shows that Acheulian bifacial technology and Levallois technology are homologous, reflecting an ancestor-descendant relationship (36). Rather than a “technical breakthrough” that spread from a single point of origin, Levallois technology resulted from the gradual synthesis of stone knapping behaviors shared among hominins in Africa and those indigenous to the Acheulian dispersal area in Eurasia (Fig. 1). Consequently, the development of Levallois technology within Late Acheulian contexts represents instances of technological convergence.


Science 26 September 2014: Vol. 345 no. 6204 pp. 1609-1613 DOI: 10.1126/science.1256484

Early Levallois technology and the Lower to Middle Paleolithic transition in the Southern Caucasus 

D. S. Adler

ABSTRACT The Lower to Middle Paleolithic transition (~400,000 to 200,000 years ago) is marked by technical, behavioral, and anatomical changes among hominin populations throughout Africa and Eurasia. The replacement of bifacial stone tools, such as handaxes, by tools made on flakes detached from Levallois cores documents the most important conceptual shift in stone tool production strategies since the advent of bifacial technology more than one million years earlier and has been argued to result from the expansion of archaic Homo sapiens out of Africa. Our data from Nor Geghi 1, Armenia, record the earliest synchronic use of bifacial and Levallois technology outside Africa and are consistent with the hypothesis that this transition occurred independently within geographically dispersed, technologically precocious hominin populations with a shared technological ancestry.

Link

September 23, 2014

ESHE 2014 abstracts

The abstracts for the European Society for the study of Human Evolution meeting that just took place are available in this PDF.


September 09, 2014

An archaeological scenario for Out of Arabia

Jeffrey Rose and Anthony Marks have a preprint in which he details an archaeological scenario for the emergence of the Emiran (arguably the best candidate for the ur-Upper Paleolithic at the moment) from Arabian progenitors who themselves had Northeast African Nubian Levallois progenitors. I proposed Out of Arabia a few years ago and followed research suggestive of such a trajectory of modern humans in various posts under the Out of Arabia label.

In a nutshell, it seems to me that the 50kya OoAfrica model is wrong, falsified by (i) the dating of Neandertal adixture (which precedes it and could only have happened outside of Africa), (ii) the dating of human mtDNA and NRY trees in numerous papers that show a split that precedes 50kya. This in itself proves that the Upper Paleolithic (which is attested in the post-50kya period and rapidly spreads across Eurasia in a genetic Big Bang of expansion leading to the full disappearance of Neandertals by ~40kya) must have local Eurasian origins rather than being an import from Africa.

If UP is not linked to the Out-of-Africa event, then two questions arise: (i) how did the UP arise in Eurasia, and (ii) when did the Out-of-Africa event take place? The increasing adoption of a "slow mutation rate", the discovery of a potential ~100kya layer of ancestry separating Europeans from East Asians, and, on the archaeology side, the proliferation of evidence against the "coastal migration route" all hint in OoAfrica taking place much earlier than the UP revolution in answer to question (ii).  Indeed, one of the few stumbling blocks of a much earlier Out-of-Africa (the date of L3~70kya) may actually be falling, if it turns out that African L3 is nested within Eurasian M+N and not vice versa. The new preprint by Rose snf Marks helps answer question (i) by proposing an archaeological scenario that derives the UP of the Levant from the MP of Arabia.

From the paper:
In sum, the tool assemblages of the early Emiran include a combination of both classic UP tool types and MP Levallois points; it cannot be accurately characterized as fully UP, rather, an amalgamation of MP and UP forms. Viewed solely within a Levantine context, the technological and typological patterning of the early Emiran might suggest it derived from local innovation without significant external demographic input. 
... 
So, with no clear cut antecedents in the Levant, do the three Emiran technological traits that have no deep Levantine ancestry (i.e., bidirectional core preparation, the use of cresting, and the presence of lateral modification on Levallois points), have  demonstrable origins elsewhere? Conversely, do those deeply rooted Levantine characteristics of the Emiran (i.e., elongated Levallois point production and UP tool  manufacture) have comparable analogues in adjacent areas? 
...  
Given these technological and typological considerations, we find no direct relationship between any northeast African MIS 5 industry and the early Emiran. The African data do suggest that the Emiran preferential bidirectional Levallois point production strategy ultimately arose in northeast Africa during late MIS 6. This reduction strategy became increasingly widespread during MIS 5, where it spread as far south as the Ethiopian Rift and east into the Arabian Peninsula. This wide distribution suggests extensive cultural contact, either direct or indirect, along the Nile Valley and across the Red Sea during the Last Interglacial, when climatic conditions were optimal. 
...  
By MIS 5.3 (~ 100 ka), perhaps, even as early as the Last Interglacial, the African Nubian Complex was widespread in Arabia, from the Yemeni Hadramawt to the eastern edge of the Nejd Plateau in southern Oman. Additional manifestations of this technocomplex have been found in the Rub' al Khali, central Saudi Arabia, and the Al Jawf basin of northern Saudi Arabia, less than 300 km southeast of ‘Ain Difla. Given the Nilotic origin of the Nubian Complex, its presence in Arabia may be firmly understood as a huntergatherer range expansion out of northeast Africa.  
...  
The techno-typological patterns we have observed point to an origin of the Emiran that was neither wholly rooted in the Levant nor the result of a complete demographic replacement from groups expanding out of Africa; rather, the Emiran combines elements of the Nubian Levallois system with typological elements from the southern Levantine Mousterian. This scenario envisions a zone stretching across the interface of northwestern Arabia and the southern Levant, where the territories of Levantine and Arabian huntergatherer populations overlapped during MIS 5. Bilateral exchange over time resulted in the incorporation of an Afro-Arabian core reduction strategy with a Levantine toolmaking tradition that extends back to the Early Mousterian. 
...  
African Nubian Complex toolmakers, at least, were modern humans. AMH specimens have been documented in North Africa from 150 ka onward (Smith et al., 2007; Hublin and McPherron, 2012), while no other species has yet been found there. An AMH child burial was excavated from an extraction pit associated with Activity Phase III at Taramsa Hill 1 (Vermeersch et al., 1998; Van Peer et al., 2010), with a terminus post quem of ca. 70 ka. Given the technological similarity of the Classic Dhofar Nubian and the Late Nubian Complex of the Middle Nile Valley in Egypt, as well as the fact that there is no evidence for prior MP human occupation in southern Oman, it is reasonable to associate the distribution of Nubian Complex sites with a population of AMHs spread across northeast Africa and the Arabian Peninsula. The presence of Nubian Levallois technology in southern Arabia and the Horn of Africa (Clark, 1954; Kurashina, 1978; Clark, 1988; Beyin, 2013), as well as northern Arabia and in the Red Sea hills of Egypt, suggests that early human groups traveled to and from Africa via both the Arabian and Levantine Corridors.
It is unfortunate that Arabia is so poor (to wholly deficient?) in ancient human remains from this critical period. Nonetheless, it makes sense that if modern humans were present in Northeast Africa in association with Nubian Complex tools, they would be the ones who carried them to Arabia. The presence of AMH in the Levant (associated with Mousterian tools) was often dismissed until recently as the Out-of-Africa that failed, partly because the Shkul/Qafzeh hominins were the only pre-UP modern humans in Eurasia (making their extinction plausible) and partly because of the widespread view that Out-of-Africa happened ~70-50kya (which by definition would imply that the Mount Carmel hominins weren't the Out-of-Africa.

However, if AMH were also present in Arabia during the MP it is much more difficult to argue for extinction of Eurasian modern humans and later replacement by a "late" Out-of-Africa event: this would imply that both the Levantine and Arabian humans would disappear. Moreover, the genetics no longer requires a late Out-of-Africa event and the UP is no longer plausibly concurrent with the OoAfrica event. In short, a quite simple explanation is that one group of AMH (from Arabia) mixed with another group of AMH (from the Levant) and the UP arose in this population. The latter group (from the Levant) lived in proximity to Neandertals and thus the evidence for Neandertal admixture in non-Africans is easily explained (no need to invoke unattested Neandertals admixing with "coastal route" migrating humans).

"Out of Arabia" and the Middle-Upper Palaeolithic transition in the southern Levant 

Jeffrey I. Rose, Anthony E. Marks

Beginning some 50 thousand years ago, a technological transition spread across the Near East and into Eurasia, in the most general terms characterized by a shift from preferential, prepared core reduction systems to the serial production of elongated points via opposed platform cores. The earliest known occurrence of such a technological shift is the Emiran Industry, whose earliest manifestations are found in the southern Levant. The cultural and demographic source(s) of this industry, however, remain unresolved. Looking to archaeogenetic research, the emerging picture indicates a major dispersal of our species out of Africa between 100 and 50 thousand years ago. Ancient DNA evidence points to low levels of admixture between Neanderthal and these pioneering modern human populations, which some suggest occurred in the Near East between 60 and 40 thousand years ago. These propositions underscore the significance of the Emiran and beg a reassessment of its origins. In this paper, we ask whether the Emiran was a local development, a cultural/demographic replacement, or the fusion of indigenous and exogenous lithic traditions. Our analysis considers the techno-typological features of the early Emiran in relation to late Middle Palaeolithic and contemporaneous assemblages from adjacent territories in Northeast Africa and the Arabian Peninsula, in order to identify overlapping cultural features and potential antecedents. Parsimonious with the archaeogenetic scenario of admixture, the Emiran seems to represent a fusion of local southern Levantine Mousterian typological elements with the Afro-Arabian Nubian Levallois reduction strategy. We conclude that the Emiran is primarily rooted in the Early Nubian Complex of the Nile Valley, which spread into the Arabian Peninsula during the Last Interglacial and developed at the interface of these two contextual areas between 100 and 50 thousand years ago.

Link

July 17, 2014

Early Neandertal disappearance in Iberia

Journal of Human Evolution DOI: 10.1016/j.jhevol.2014.06.002

New evidence of early Neanderthal disappearance in the Iberian Peninsula

Bertila Galván et al.

The timing of the end of the Middle Palaeolithic and the disappearance of Neanderthals continue to be strongly debated. Current chronometric evidence from different European sites pushes the end of the Middle Palaeolithic throughout the continent back to around 42 thousand years ago (ka). This has called into question some of the dates from the Iberian Peninsula, previously considered as one of the last refuge zones of the Neanderthals. Evidence of Neanderthal occupation in Iberia after 42 ka is now very scarce and open to debate on chronological and technological grounds. Here we report thermoluminescence (TL) and optically stimulated luminescence (OSL) dates from El Salt, a Middle Palaeolithic site in Alicante, Spain, the archaeological sequence of which shows a transition from recurrent to sporadic human occupation culminating in the abandonment of the site. The new dates place this sequence within MIS 3, between ca. 60 and 45 ka. An abrupt sedimentary change towards the top of the sequence suggests a strong aridification episode coinciding with the last Neanderthal occupation of the site. These results are in agreement with current chronometric data from other sites in the Iberian Peninsula and point towards possible breakdown and disappearance of the Neanderthal local population around the time of the Heinrich 5 event. Iberian sites with recent dates (less than 40 ka) attributed to the Middle Palaeolithic should be revised in the light of these data.

Link

June 21, 2014

Sima de los Huesos hominins: ~430 thousand years old and on the Neandertal lineage

Science 20 June 2014: Vol. 344 no. 6190 pp. 1358-1363 DOI: 10.1126/science.1253958

Neandertal roots: Cranial and chronological evidence from Sima de los Huesos

J. L. Arsuaga et al.

Seventeen Middle Pleistocene crania from the Sima de los Huesos site (Atapuerca, Spain) are analyzed, including seven new specimens. This sample makes it possible to thoroughly characterize a Middle Pleistocene hominin paleodeme and to address hypotheses about the origin and evolution of the Neandertals. Using a variety of techniques, the hominin-bearing layer could be reassigned to a period around 430,000 years ago. The sample shows a consistent morphological pattern with derived Neandertal features present in the face and anterior vault, many of which are related to the masticatory apparatus. This suggests that facial modification was the first step in the evolution of the Neandertal lineage, pointing to a mosaic pattern of evolution, with different anatomical and functional modules evolving at different rates.

Link

June 13, 2014

An older layer of Eurasian admixture in Eastern Africa

The authors propose that a genetic component found in Horn of Africa populations back-migrated to Africa from Eurasia ~23 thousand years ago. I did not read this carefully yet, but it seems reasonably plausible. The migration uncovered by Pagani et al. and Pickrell et al. (~3kya) is probably not the whole story of Eurasian back-migration into Africa; that episode probably involved only Semitic speakers (it's hard to imagine any other language being carried from the Middle East at that time frame). But the Eurasian affiliation of East Africans extends well beyond Semitic speakers. In North Africa this is even clearer as the native (pre-Arab) population is definitely broadly West Eurasian and this must have come about by back-migration.

The back-migration of M1 and U6 into Africa seems to be at a similar time depth as the one proposed by these authors (post-initial UP, but pre-Neolithic). I have proposed that haplogroup E may represent an even earlier layer of Eurasian back-migration, while the signals identified by Pagani et al. and Pickrell et al. in East Africa, Pickrell et al. for Southern Africa, and the limited (but present) Neandertal ancestry in Yoruba and Pygmies documented by Pruefer et al. represent later events. The arrival of Arabs and Europeans are later events still.

For a time, there was a taboo against imagining back-migration into Africa; in a sense this was reasonable on parsimony grounds: Africans have most autosomal genetic diversity and the basal clades of mtDNA and Y-chromosomes; a model with Out-of-Africa is simpler than one with both Out-of and Into-Africa. However, we now know that pretty much all Africans have Eurasian ancestry, ranging from at least traces in theYoruba and Pygmies (to account for the Neandertal admixture) to intermediate values in East Africans, to quite  a lot in North Africans.

Eurasian admixture in Africa seems to be general, variable, and to have occurred at different time scales. It's still the best hypothesis that modern humans originated in Africa initially and migrated into Eurasia. However, it is no longer clear that Africa was always the pump and never the destination of human migrations.

PLoS Genet 10(6): e1004393. doi:10.1371/journal.pgen.1004393

Early Back-to-Africa Migration into the Horn of Africa

Jason A. Hodgson

Genetic studies have identified substantial non-African admixture in the Horn of Africa (HOA). In the most recent genomic studies, this non-African ancestry has been attributed to admixture with Middle Eastern populations during the last few thousand years. However, mitochondrial and Y chromosome data are suggestive of earlier episodes of admixture. To investigate this further, we generated new genome-wide SNP data for a Yemeni population sample and merged these new data with published genome-wide genetic data from the HOA and a broad selection of surrounding populations. We used multidimensional scaling and ADMIXTURE methods in an exploratory data analysis to develop hypotheses on admixture and population structure in HOA populations. These analyses suggested that there might be distinct, differentiated African and non-African ancestries in the HOA. After partitioning the SNP data into African and non-African origin chromosome segments, we found support for a distinct African (Ethiopic) ancestry and a distinct non-African (Ethio-Somali) ancestry in HOA populations. The African Ethiopic ancestry is tightly restricted to HOA populations and likely represents an autochthonous HOA population. The non-African ancestry in the HOA, which is primarily attributed to a novel Ethio-Somali inferred ancestry component, is significantly differentiated from all neighboring non-African ancestries in North Africa, the Levant, and Arabia. The Ethio-Somali ancestry is found in all admixed HOA ethnic groups, shows little inter-individual variance within these ethnic groups, is estimated to have diverged from all other non-African ancestries by at least 23 ka, and does not carry the unique Arabian lactase persistence allele that arose about 4 ka. Taking into account published mitochondrial, Y chromosome, paleoclimate, and archaeological data, we find that the time of the Ethio-Somali back-to-Africa migration is most likely pre-agricultural.

Link