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

Chauvet cave art not the work of earliest Europeans

Many of you may have watched Cave of Forgotten Dreams, a great documentary about the paintings of Chauvet cave in France. It now turns out that the extraordinary art preserved in the cave may not date to ~36,000 years but rather to the Gravettian or Solutrean period.

 L'Anthropologie Available online 11 February 2014

New investigations into the cultural and stylistic identity of the Chauvet cave and its radiocarbon dating

Jean Combiera, Guy Jouve

The discovery of Chauvet cave, at Vallon-Pont-d’Arc (Ardèche), in 1994, was an important event for our knowledge of palaeolithic parietal art as a whole. Its painted and engraved figures, thanks to their number (425 graphic units), and their excellent state of preservation, provide a documentary thesaurus comparable to that of the greatest sites known, and far beyond what had already been found in the group of Rhône valley caves (Ardèche and Gard). But its study – when one places it in its natural regional, cultural and thematic framework – makes it impossible to see it as an isolated entity of astonishing precocity. This needs to be reconsidered, and the affinities that our research has brought to light are clearly incompatible with the very early age which has been attributed to it. And if one extends this examination to the whole of the Franco-Cantabrian domain, the conclusion is inescapable: although Chauvet cave displays some unique characteristics (like every decorated cave), it belongs to an evolved phase of parietal art that is far removed from the motifs of its origins (known from art on blocks and on shelter walls dated by stratigraphy to the Aurignacian, in France and Cantabrian Spain). The majority of its works are therefore to be placed, quite normally, within the framework of the well-defined artistic creations of the Gravettian and Solutrean. Moreover, this phase of the Middle Upper Palaeolithic (26,000–18,000) coincides with a particularly intensive and diversified local human occupation, unknown in earlier periods and far less dense afterwards in the Magdalenian. A detailed critique of the treatment of the samples subjected to AMS radiocarbon dating makes it impossible to retain the very early age (36,000 cal BP) attributed by some authors to the painted and engraved figures of Chauvet cave.

Link

ESHE 2012 abstracts

Some abstracts of interest from the European Society for the study of Human Evolution 2012 meeting (pdf). To avoid making this too long, I will just post the titles and the most relevant quotes. You can read the abstracts in the linked pdf for authors names and more information.

Neandertal and Denisovan Genomes from the Altai 

Susanna Sawyer  et al.

In 2010 a draft genome sequence was determined from a small finger bone found in Denisova Cave in southern Siberia. Its analysis revealed that it derives from an individual who belonged to a population related to, but distinct from, Neandertals. A molar has also been described from Denisova Cave and has shown to carry an mtDNA genome closely related to that of the finger bone.  We have recently determined the DNA sequence of the Denisova genome to a quality similar to present-day human genomes. We have also retrieved a complete mitochondrial genome and nuclear DNA sequences from an additional molar found in Denisova Cave. Furthermore, we have determined a high-quality nuclear genome from a pedal phalanx found in Denisova Cave in 2010. We show that the pedal phalanx derived from a Neandertal and thus that Neandertals as well as Denisovans have been present in the cave. We will discuss the genetic history of Denisovans as well as Neandertals in light of these new genome sequences. 

The discovery of a Neandertal genome from Denisova cave is certainly interesting. I have previously commented that:

If Vindija and Denisova, two caves less than 5,000km apart were home to people more divergent from each other than any two humans are today, it's strange to think that only "modern humans" inhabited Africa at the same time.

Now, it appears that Neandertals and Denisovans were present (when?) not only 5Mm apart, but literally on the same spot. Much later, during the Neolithic we see very differentiated humans co-existing in Europe. And, we get archaic hominins in Africa long after the appearance of anatomically modern humans there. I think the evidence is looking good for my hypothesis that regional human populations have recently gotten more similar over time through extensive admixture between divergent hominin groups, rather than that they became more dissimilar over time  through tree-like divergence.

On the same topic, here is more evidence for Neandertal presence in the Altai:

A Neanderthal mandible fragment from Chagyrskaya Cave (Altai Mountains, Russian Federation)

Both the mandible and the dentition preserve numerous derived Neanderthal traits: among else a posteriorly placed mandibular foramen, an oblique mylohyoid line, an asymmetrical P4 and continuous mid-trigonid crests on the M1 and M2. ... Ongoing ancient DNA analyses of the hominin remains from Chagyrskaya cave and absolute dates for the site will hopefully help to clarify the origin of the Altai Neanderthals, and their relationship with the Denisovans.

An hypothesis for the phylogenetic position of Homo floresiensis

Our cladistic analysis places H. floresiensis unequivocally as part of a clade with H. habilis

Who are you calling ”modern”? An assessment of the dental morphology and metrics of Homo sapiens

Although dental reduction has long been cited as a derived feature of H. sapiens, our data indicate this claim may be no longer tenable ... the single metrical assessment that groups all H. sapiens (early, Upper Paleolithic and recent) apart from other taxa is the ratio between mandibular:maxillary crown areas.  the results of our study are important for assessing recent claims of great antiquity for H. sapiens outside of Africa

Neanderthal in Malthusian demographic trap

It can be hypothesized that the demography of the Neanderthal metapopulation, living under conditions where extreme environmental instability with short periods was the norm, was primarily stagnant,

with frequent bottlenecks and episodes of decline.

 A New Framework for the Upper Paleolithic of Eastern Europe

The results of field and laboratory research during the past decade require a new classificatory framework for the Upper Paleolithic in Eastern Europe. It is now apparent that people making artifacts assigned to the Ahmarian industry occupied both the southern and northern slopes of the Caucasus Mountains (i.e., Ortvale Klde, Layer 4d; Mezmaiskaya Cave, Layer 1C). Their sites probably indicate a separate movement of anatomically modern humans (AMH) from the Near East directly into Eastern Europe, establishing an independent line of development during the earlier Upper Paleolithic that parallels the Proto-Aurignacian and Aurignacian sequence in Western and Central Europe. this East European industry is most fully represented at the Kostenki-Borshchevo sites on the Don River before 40,000 cal BP (e.g., Kostenki 14, Layer IVb). It is followed by a closely related industry, also characterized by bladelet production, that is dated to the interval between 40,000 and 30,000 cal BP in Crimea and the East European Plain. The proposed new framework reflects recognition of these distinctive East European entities and of two environmental events that had significant impacts on human settlement in Eastern Europe: (1) the Campanian Ignimbrite (CI) volcanic eruption (40,000 cal BP); and (2) the Last Glacial Maximum (LGM) ( 25,000 cal BP). It has been suggested that the early Upper Paleolithic (EUP) industry present in Eastern Europe before 40,000 cal BP should be labeled an eastern variant of the contemporaneous Proto-Aurignacian of Mediterranean Europe. However, given the separate movement of people from the Near East via the Caucasus Mountains, and independent development of the East European EUP, this industry is more appropriately termed “Proto-Gravettian.” The younger bladelet industry, which includes assemblages at Buran-Kaya III (Layer 6-1), Mira (Layer II/2), Kostenki 8 (Layer II), and probably Shlyakh (Layers 4C, 6), may be termed “Early Gravettian” to distinguish it from the classic Gravettian industry that dates to less than 30,000 cal BP (e.g., Avdeevo, Zaraisk).The upper temporal boundary of the Proto-Gravettian corresponds to the CI eruption (40,000 cal BP), while the classic Gravettian of the East European Plain appears to have been effectively terminated by the LGM ( 25,000 cal BP). Several sites that date to the 40,000–30,000 cal BP interval (e.g., Kostenki 1, Layer III) contain elements that suggest a connection with the Aurignacian technocomplex of Western-Central Europe. These assemblages may be placed into the category of “Eastern Aurignacian,” which reflects differences in content with the West and Central European sites. The apparent spread of this industry into Eastern Europe from Central Europe may be related to the impact of the CI eruption on portions of the East European Plain. 

 Conflicting dates for the Late Aterian

First at the huge Ifri n’Ammar sites, TL dates have indicated 80,000 years for the Late Middle Palaeolithic/Aterian levels. Our new C14 dates yield 35,000 BP for exactly the same levels. At the “grotte des Contrebandiers”, formerly dated at 28,000 BP by Debenath and his team, is now dated at 100,000 years by new TL dates. As starting points, this kind of methodological contradiction should be confronted, understood and resolved.

 The Rio Secco Cave in the North Adriatic Region, Italy. A new context for investigating the Neanderthal demise and the settllement of Anatomically Modern Humans

A sequence of several thin layers dated to 46.0–42.1ky Cal BP represents the final Mousterian.

The Dhofar Nubian Tradition: an enduring Middle Stone Age technocomplex in southern Arabia

Between 2010 and 2012, the Dhofar Archaeological Project has located and mapped 260 Nubian Complex occurrences across the Nejd Plateau of southern Oman. Diagnostic Nubian artifacts werefound cemented in fluvial sediments at the site of Aybut Al Auwal in Dhofar, with two OSL dates around 106 ka BP; hence, roughly contemporaneous with the African Nubian Complex (Rose et al. 2011). Many of these lithic assemblages, such as that from Aybut al Auwal, are technologically homologous to the Late Nubian Industry found in northeast Africa, sensu stricto, while others may represent local facies of the greater “Afro-Arabian Nubian Technocomplex.” This presentation describes the various reduction strategies encountered at a sample of Nubian Complex sites from Oman, explores inter-assemblage variability, and begins to articulate technological units within the “Dhofar Nubian Tradition.” To achieve this aim, we have developed an analytical scheme with which to describe technological variability among Nubian Levallois reduction strategies in both Africa and Arabia. Our analysis indicates at least two distinct Nubian industries. The first, which we refer to as the “Classic Dhofar Nubian,” is virtually identical to Late Nubian Industry from the Lower Nile Valley and Red Sea Hills in Egypt. Thee subsequent group of assemblages in Dhofar, called the “Mudayyan,” exhibits a technological shift toward diminutive Nubian Levallois cores and that, recurrent bidirectional cores with opposed, faceted striking platforms. We interpret this evidence to indicate an enduring, local Nubian tradition in Dhofar that is ultimately rooted in the African Nubian Complex. 

From Late Mousterian to Evolved Aurignacian: New evidence for the Middle-to-Upper Paleolithic transition in Mediterranean Spain

Combined, the evidence from CA and FDM indicates that, in chronostratigraphic terms, the Middle-to-Upper Paleolithic transition in Murcia consists of the replacement of a Late Mousterian by an Evolved Aurignacian and occurred some time during the 38th millennium cal BP

Human remains from the Moravian Gravettian

International Journal of Osteoarchaeology doi:10.1002/oa.1088

Human remains from the Moravian Gravettian: morphology and taphonomy of additional elements from Dolní Vestonice II and Pavlov I

E. Trinkaus et al.

Abstract

Zooarchaeological analysis of the earlier Mid Upper Paleolithic (MUP) (Pavlovian) assemblages from Dolní Vstonice II and Pavlov I, southern Moravia, have yielded 11 additional remains from Dolní Vstonice II (five of which may be associated) and 20 remains from Pavlov I (16 of which come from a pair of hands, Pavlov 31). These remains are those of early modern humans, albeit with a few generally archaic features. At least two of them represent very tall individuals, among the tallest known for the Upper Paleolithic. These remains also raise the question, previously posed, as to the nature of differential treatment of the dead among MUP humans, given the presence of ritual burials, isolated bones and (with Pavlov 31) selected associated anatomy. Copyright © 2009 John Wiley & Sons, Ltd.

Link

35,000-year old female figurine from Hohle Fels Cave

This is said to be the oldest currently known depiction of the human form. There is also a free video in the Nature site; see also a BBC story with more pics.

From the paper:

The new figurine from Hohle Fels radically changes our view of the origins of Palaeolithic art. Before this discovery, animals and therianthropic imagery dominated the two dozen figurines from the Swabian Aurignacian. Female imagery was entirely unknown2, 15. With this discovery, the widespread notion that three-dimensional female depictions developed in the Gravettian can be rejected

Nature doi:10.1038/nature07995


A female figurine from the basal Aurignacian of Hohle Fels Cave in southwestern Germany

Nicholas J. Conard

Abstract

Despite well over 100 years of research and debate, the origins of art remain contentious1, 2, 3. In recent years, abstract depictions have been documented at southern African sites dating to approx75 kyr before present (bp)4, 5, and the earliest figurative art, which is often seen as an important proxy for advanced symbolic communication, has been documented in Europe as dating to between 30 and 40 kyr bp 2. Here I report the discovery of a female mammoth-ivory figurine in the basal Aurignacian deposit at Hohle Fels Cave in the Swabian Jura of southwestern Germany during excavations in 2008. This figurine was produced at least 35,000 calendar years ago, making it one of the oldest known examples of figurative art. This discovery predates the well-known Venuses from the Gravettian culture by at least 5,000 years and radically changes our views of the context and meaning of the earliest Palaeolithic art.

Link

Erik Trinkaus on Neanderthal admixture with early modern humans in Europe

Via Yann a link to a new article by Erik Trinkaus suggesting that early modern humans in Europe cannot be simply explained as the result of an expansion of African modern humans but exhibit features that are not found in earliest African modern humans.

According to Trinkaus, the early modern Europeans exhibit features that are consistent with Neanderthal admixture. This is certainly the case, but that does not mean that the case of admixture is clear-cut: the earliest modern Africans are represented by less than a handful of specimens; moreover these are separated by 100ky at least from the earliest modern Europeans. Thus, neither the African population of origin, neither its evolutionary history up to the time of the African Exodus are well characterized.

It is possible that modern Out-of-Africans (whom I have called elsewhere Afrasians) were already different from the earliest anatomically modern Africans. We simply do not know much about them skeletally. Their main features are usually inferred by either (a) looking at early modern humans in Africa and seeing how they differ from previous Africans, or (b) looking at early modern humans in Eurasia and seeing how they are different from previous Eurasians and similar to each other. Both these approaches have led to a rather minimalist definition of modern humans; consequently, features that cannot be explained well under this definition are attributed to admixture.

As the genomic study of Neanderthals progresses, we should be able to find direct evidence for the introgression of Neanderthal genetic material into Homo sapiens. I suspect that such positive evidence (or negative evidence, assuming enough Neanderthal DNA is retrieved) would finally decide the question one way or another.

PNAS (Published online)

European early modern humans and the fate of the Neandertals

Erik Trinkaus

Abstract: A consideration of the morphological aspects of the earliest modern humans in Europe (more than 33,000 B.P.) and the subsequent Gravettian human remains indicates that they possess an anatomical pattern congruent with the autapomorphic (derived) morphology of the earliest (Middle Paleolithic) African modern humans. However, they exhibit a variable suite of features that are either distinctive Neandertal traits and/or plesiomorphic (ancestral) aspects that had been lost among the African Middle Paleolithic modern humans. These features include aspects of neurocranial shape, basicranial external morphology, mandibular ramal and symphyseal form, dental morphology and size, and anteroposterior dental proportions, as well as aspects of the clavicles, scapulae, metacarpals, and appendicular proportions. The ubiquitous and variable presence of these morphological features in the European earlier modern human samples can only be parsimoniously explained as a product of modest levels of assimilation of Neandertals into early modern human populations as the latter dispersed across Europe. This interpretation is in agreement with current analyses of recent and past human molecular data.

Link

Upper Paleolithic and Mesolithic around the Mediterranean

A new article in L' Anthropologie reviews much of the archaeological evidence about the Upper Paleolithic and Mesolithic in the Mediterranean basin.

L' Anthropologie (Article in press)

The Upper Paleolithic and the Mesolithic around the Mediterranean: cultural framework

Janusz K. Kozlowski

Abstract

The origin of the Upper Palaeolithic around the Mediterranean was the result of the local evolution, particularly in the Near East and in the Lower Nile basin, and of the migration from this zone to South-Eastern and Central Europe. The Initial Upper Palaeolithic in the Near East belt was the effect of local evolution from the industries based on Levallois concept to the industries which developed leptolithic blade technologies. This evolution is well registered in multi-layer sites in the Syro-Palestinian belt (Emirian/Ahmarian), which was the starting point of the diffusion of these “transitional” industries in South-Eastern and Central Europe. This diffusion could be identified with the migration of first anatomically Modern Humans. The Early Upper Palaeolithic in Europe — dated to the second half of the Interpleniglacial — was, at least partially, based on these “transitional” industries and manifested by the appearance of the Aurignacian, contrasted with local cultures such as the Uluzzian in Mediterranean Europe. During whole the Interpleniglacial Europe was separated from Northern Africa dominated by local evolution of Middle Palaeolithic (Middle Stone Age) cultures (mostly expressed by the Aterian), and by specific “transitional” industries on the southern Mediterranean coast (Early Dabbian) and in the Lower Nile basin. The Last Glacial Maximum and the corresponding sea level recession opened new possibilities of contacts between the Maghreb and the Iberian Peninsula in both directions (Aterian-Solutrean and Gravettian-Early Iberomaurusian), which are still difficult to be proved before new chronostratigraphic correlations are made. At the same time we register links between south-eastern Europe and western Anatolia; the real border between Near Eastern and European Mediterranean cultural zones was marked, in the Late Glacial, by the Taurus chain. During the Late Glacial the cultural separation between Europe and Africa was particularly marked. Only in the Aegean basin the first sea navigation facilitated contacts which become widespread as late as in the Early Holocene with neolithization trough maritime contacts.

Link

Earliest shoe wearers

A new article by Erik Trinkaus sheds some light into the antiquity of shoe wearing. Shoes are usually made from perishable materials, so there is usually little direct evidence for them, except for quite recent times. In older times, there are sometimes footprints which show evidence of being produced with covered feet.

Dr. Trinkaus studied the morphology of toes from prehistoric humans. Roughly speaking, toes in shoes do not need to "grab" onto the ground, because this function is performed by the shoe. This is especially true for the lesser toes, i.e., toes other than the big toe. So, the lesser toes should shrink when humans began to use shoes regularly.

Indeed, there was evidence that lesser toes did shrink in Paleolithic Western Eurasians. Early modern humans ("Cro-Magnons") but also late Neanderthals may have started using shoes as protection against the cold and for protection from the ground. Moreover, both southern European and more northern individuals seem to have been affected, and this may indicate that this was a general cultural practice that was adopted, rather than a specific measure to combat the cold in the northernmost parts of Eurasia.

Journal of Archaeological Science Volume 32 Issue 10, 1515-1526

Anatomical evidence for the antiquity of human footwear use

Erik Trinkaus

Abstract

Archeological evidence suggests that footwear was in use by at least the middle Upper Paleolithic (Gravettian) in portions of Europe, but the frequency of use and the mechanical protection provided are unclear from these data. A comparative biomechanical analysis of the proximal pedal phalanges of western Eurasian Middle Paleolithic and middle Upper Paleolithic humans, in the context of those of variably shod recent humans, indicates that supportive footwear was rare in the Middle Paleolithic, but that it became frequent by the middle Upper Paleolithic. This interpretation is based principally on the marked reduction in the robusticity of the lesser toes in the context of little or no reduction in overall lower limb locomotor robusticity by the time of the middle Upper Paleolithic.

Link