43,000-year old Aurignacian in Swabian Jura

43,000-year old Aurignacian in Swabian Jura

A new paper continues the re-assessment of the radiocarbon dating record in Europe. It pushes the Aurignacian of Central Europe back in time, but not as far back as the appearance of modern humans in Europe. The implication is that the advanced music and art of the Aurignacian did not accompany modern humans as they made their first steps into Europe, but rather developed there.

The authors distinguish between a "strong" version of their model (which would posit a monocentric origin of music/art around the Geissenkoesterle site), and a "weak" one in which these innovations were contributed in parallel by different regions. A better understanding of the origin of different innovations and their assignment to specific groups of modern humans may help us better understand what was the "common core" of behavioral and technological modernity that facilitated the success of our species.

From the paper:

The majority of scholars conclude that the Aurignacian is the earliest signature of the first modern humans in Europe. Recent research suggests that this is not likely to be the case. Benazzi et al. (2011) have shown that the Uluzzian of Italy and Greece is likely to be a modern human industry based on the reanalysis of infant teeth in the archaeological site of Cavallo, and also demonstrated that it dates to 45,000-43,000 cal BP. Other dated examples from other Uluzzian sites (e.g., Higham et al., 2009) fall into the same period, and the Uluzzian is always stratigraphically below the Proto- Aurignacian in Italian sites where both co-occur. This adds an additional level of complexity to the emerging picture of early human dispersals and suggests that the Aurignacian does not represent the earliest evidence of our species in Europe. 

... 

Taken together, these results suggest that modern humans arrived in Europe as early as ~45,000 cal BP and spread rapidly across Europe to as far as southern England between 43,000 and41,000 cal BP. The dates for the lower Aurignacian at Geissenklosterle fall in the same period and appear to pre-date the ages for the Proto- Aurignacian and Early Aurignacian in other regions (Fig. 6). The new results suggest that the caves of the Swabian Jura document the earliest phase of the Aurignacian, and the region can be viewed as one of the key areas in which a variety of cultural innovations, including figurative art, mythical images, and musical instruments, are first documented. These dates are consistent with the Danube Valley serving as an important corridor for the movement of people and ideas (Conard, 2002; Conard and Bolus, 2003). 

... 

The new radiocarbon dates from Geissenklosterle document the presence of the Aurignacian in the Swabian Jura prior to the Heinrich 4 cold phase, with the Early Aurignacian beginning around 42,500 cal BP. In the coming years, excavations in the Swabian Jura will continue and new radiometric dates should contribute to an improved understanding of the spatial-temporal development of the Aurignacian and its innovative material culture.

From the press release:

Researchers from Oxford and Tübingen have published new radiocarbon dates from the from Geißenklösterle Cave in Swabian Jura of Southwestern Germany in the Journal of Human Evolution. The new dates use improved methods to remove contamination and produced ages between began between 42,000 – 43,000 years ago for start of the Aurignacian, the first culture to produce a wide range of figurative art, music and other key innovations as postulated in the Kulturpumpe Hypothesis. The full spectrum of these innovations were established in the region no later than 40 000 years ago.

Journal of Human Evolution doi:10.1016/j.jhevol.2012.03.003

Τesting models for the beginnings of the Aurignacian and the advent of figurative art and music: The radiocarbon chronology of Geißenklösterle

Thomas Higham et al.

The German site of Geißenklösterle is crucial to debates concerning the European Middle to Upper Palaeolithic transition and the origins of the Aurignacian in Europe. Previous dates from the site are central to an important hypothesis, the Kulturpumpe model, which posits that the Swabian Jura was an area where crucial behavioural developments took place and then spread to other parts of Europe. The previous chronology (critical to the model), is based mainly on radiocarbon dating, but remains poorly constrained due to the dating resolution and the variability of dates. The cause of these problems is disputed, but two principal explanations have been proposed: a) larger than expected variations in the production of atmospheric radiocarbon, and b) taphonomic influences in the site mixing the bones that were dated into different parts of the site. We reinvestigate the chronology using a new series of radiocarbon determinations obtained from the Mousterian, Aurignacian and Gravettian levels. The results strongly imply that the previous dates were affected by insufficient decontamination of the bone collagen prior to dating. Using an ultrafiltration protocol the chronometric picture becomes much clearer. Comparison of the results against other recently dated sites in other parts of Europe suggests the Early Aurignacian levels are earlier than other sites in the south of France and Italy, but not as early as recently dated sites which suggest a pre-Aurignacian dispersal of modern humans to Italy by ∼45000 cal BP. They are consistent with the importance of the Danube Corridor as a key route for the movement of people and ideas. The new dates fail to refute the Kulturpumpe model and suggest that Swabian Jura is a region that contributed significantly to the evolution of symbolic behaviour as indicated by early evidence for figurative art, music and mythical imagery.

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Introgression of archaic haplotype at OAS1 in Melanesians (Mendez et al. 2012)

Introgression of archaic haplotype at OAS1 in Melanesians (Mendez et al. 2012)

It seems that Michael Hammer was good on his promise that in 2012 "This year, we should be able to confirm what we found and go way beyond that."  In a new paper, conclusive evidence is presented about introgression of an archaic sequence into Melanesian populations. The argument is as follows:

• Melanesians are more diverse in that region than Africans.
• The common ancestor of the "archaic" and "African" haplotypes lived >3 million years ago.
• The "archaic" haplotype matches the ancient DNA from the Denisova hominin.
• Balancing selection (which can sometimes maintain extremely old polymorphism) is not reasonable in this case, because it would need to maintain both "archaic" and "African" haplotypes for a long time, but then (inexplicably) would continue to operate in Melanesia and cease to operate everywhere else.

Notice that once again, this is based on resequencing a small region of the genome. This is why I am all the more confident in my prediction that the advent of full genome sequencing will uncover more archaic admixture in humans. It may not always be able to use all the above listed criteria to confirm this admixture (since we do not and cannot have ancient DNA from all the archaic hominins that once roamed the planet), but all the remaining ones will suffice to make a very good case for introgression.

What I find particularly interesting, is that Mendez et al. re-iterate a few times that genomewide averages admit to different explanations:

Full genome comparisons of the Neandertal and Denisova draft genomes with modern human sequences have revealed different amounts of shared ancestry between each of these archaic forms and anatomically modern human (AMH) populations from different geographic regions. For example, a higher proportion of SNPs was shared between non-African and Neandertal, and between Melanesian and the Denisova genomes, than between either Neandertal or Denisova and extant African genomes (Green et al. 2010; Reich et al. 2010). An intriguing possibility is that these patterns result from introgression of archaic genes into AMH populations in Eurasia. However, this SNP sharing pattern could also be explained by ancestral population structure in Africa (i.e., without the need to posit introgression). For example, if non-Africans and the ancestors of Neandertals descend from the same deme in a subdivided African population, and this structure persisted with low levels of gene flow among African residents until the ancestors of non-Africans migrated into Eurasia, then we would expect more SNP sharing between non-Africans and Neandertals (Durand et al. 2011). 

... 

While genome-wide comparisons detect more sequence agreement between non-African and Neandertal genomes, and between Melanesian and Denisova genomes, the specific loci exhibiting these signals have not yet been identified. Furthermore, current analyses do not elucidate the relative roles of recent introgression versus long-term population structure in Africa in explaining these patterns.

The current paper does a good job at showing how in one particular region archaic introgression into Melanesians is indeed the best explanation for the evidence. But, the fact that the authors seem to re-iterate the possibility of African population structure and repeatedly caution against using patterns of genomewide sharing between modern and archaic humans is a strong hint that there are more things to come on the topic.

We should remember that the widely-circulated estimates of Neandertal->Eurasian introgression are based on genomewide averages. It is true that Reich et al. (2010) identified 13 regions of potential Neandertal introgression, which together make up a very small portion of the human genome. So, the jury is out on whether African population structure or Neandertal introgression is responsible for most of the genomewide pattern.

What you can be sure of is that many scientists are busy lining up full genomes from different human populations as we speak, and finding plenty of regions where haplotypes of extremely old divergence times co-exist in our species. We will probably learn more about such efforts during 2012.



Mol Biol Evol (2012)doi: 10.1093/molbev/msr301

Global genetic variation at OAS1 provides evidence of archaic admixture in Melanesian populations

Fernando L. Mendez, Joseph C. Watkins and Michael F. Hammer

Recent analysis of DNA extracted from two Eurasian forms of archaic human show that more genetic variants are shared with humans currently living in Eurasia than with anatomically modern humans in sub-Saharan Africa. While these genome-wide average measures of genetic similarity are consistent with the hypothesis of archaic admixture in Eurasia, analyses of individual loci exhibiting the signal of archaic introgression are needed to test alternative hypotheses and investigate the admixture process. Here, we provide a detailed sequence analysis of the innate immune gene, OAS1, a locus with a divergent Melanesian haplotype that is very similar to the Denisova sequence from the Altai region of Siberia. We re-sequenced a 7 kb region encompassing the OAS1 gene in 88 individuals from 6 Old World populations (San, Biaka, Mandenka, French Basque, Han Chinese, and Papua New Guineans) and discovered previously unknown and ancient genetic variation. The 5' region of this gene has unusual patterns of diversity, including 1) higher levels of nucleotide diversity in Papuans than in sub-Saharan Africans, 2) very deep ancestry with an estimated time to the most recent common ancestor of >3 million years, and 3) a basal branching pattern with Papuan individuals on either side of the rooted network. A global geographic survey of >1500 individuals showed that the divergent Papuan haplotype is nearly restricted to populations from eastern Indonesia and Melanesia. Polymorphic sites within this haplotype are shared with the draft Denisova genome over a span of ∼90 kb and are associated with an extended block of linkage disequilibrium, supporting the hypothesis that this haplotype introgressed from an archaic source that likely lived in Eurasia.

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Earliest sapiens remains in Europe

Earliest sapiens remains in Europe

From the BBC:

They may be yellowed and worn but these ancient teeth and jaw fragment have something very revealing to say about how modern humans conquered the globe.

The specimens, unearthed in Italy and the UK, have just been confirmed as the earliest known remains of Homo sapiens in Europe.

Careful dating suggests they are more than 41,000 years old, and perhaps as much as 45,000 years old in the case of the Italian "baby teeth".
...

The re-assessments have further importance because palaeoanthropologists can now put modern humans in the caves at the same time as the stone and bone tool technologies discovered there.

There has been some doubt over who created the so-called Aurignacian artefacts at Kents Cavern and the slightly older Uluzzian technologies at Grotta del Cavallo. It could have been Neanderthals, but there is now an obvious association in time with Homo sapiens.

From the NY Times:

They had in fact discovered the oldest known skeletal remains of anatomically modern humans in the whole of Europe, two international research teams reported Wednesday.

The scientists who made the discovery and others who study human origins say they expect the findings to reignite debate over the relative capabilities of the immigrant modern humans and the indigenous Neanderthals, their closest hominid relatives; the extent of their interactions; and perhaps the reasons behind the Neanderthal extinction. The findings have already prompted speculation that the Homo sapiens migrations into Europe may have come in at least two separate waves, rather than just one.

I'll add the abstracts later. This certainly seems to be incompatible with substantial Neandertal interbreeding. If humans and Neandertals were genetically compatible species, then why would they maintain very separate morphological populations for ~10ka? We would expect the two populations to quickly merge into one. Moreover, a longer period of interbreeding in West Eurasia would have left an excess of "Neandertal" ancestry in modern West Eurasians, something we simply don't observe.

Press release:

"What the new dates mean", Benazzi summarised, "is that these two teeth from Grotta del Cavallo represent the oldest European modern human fossils currently known. This find confirms that the arrival of our species on the continent – and thus the period of coexistence with Neanderthals – was several thousand years longer than previously thought. Based on this fossil evidence, we have confirmed that modern humans and not Neanderthals are the makers of the Uluzzian culture. This has important implications to our understanding of the development of 'fully modern' human behaviour. Whether the colonisation of the continent occurred in one or more waves of expansion and which routes were followed is still to be established."

Nature (2011) doi:10.1038/nature10484

The earliest evidence for anatomically modern humans in northwestern Europe

Tom Higham et al.

The earliest anatomically modern humans in Europe are thought to have appeared around 43,000-42,000 calendar years before present (43-42 kyr cal BP), by association with Aurignacian sites and lithic assemblages assumed to have been made by modern humans rather than by Neanderthals. However, the actual physical evidence for modern humans is extremely rare, and direct dates reach no farther back than about 41-39 kyr cal BP, leaving a gap. Here we show, using stratigraphic, chronological and archaeological data, that a fragment of human maxilla from the Kent’s Cavern site, UK, dates to the earlier period. The maxilla (KC4), which was excavated in 1927, was initially diagnosed as Upper Palaeolithic modern human1. In 1989, it was directly radiocarbon dated by accelerator mass spectrometry to 36.4-34.7 kyr cal BP2. Using a Bayesian analysis of new ultrafiltered bone collagen dates in an ordered stratigraphic sequence at the site, we show that this date is a considerable underestimate. Instead, KC4 dates to 44.2-41.5 kyr cal BP. This makes it older than any other equivalently dated modern human specimen and directly contemporary with the latest European Neanderthals, thus making its taxonomic attribution crucial. We also show that in 13 dental traits KC4 possesses modern human rather than Neanderthal characteristics; three other traits show Neanderthal affinities and a further seven are ambiguous. KC4 therefore represents the oldest known anatomically modern human fossil in northwestern Europe, fills a key gap between the earliest dated Aurignacian remains and the earliest human skeletal remains, and demonstrates the wide and rapid dispersal of early modern humans across Europe more than 40 kyr ago.

Link

Nature (2011) doi:10.1038/nature10617

Early dispersal of modern humans in Europe and implications for Neanderthal behaviour

Stefano Benazzi et al.


The appearance of anatomically modern humans in Europe and the nature of the transition from the Middle to Upper Palaeolithic are matters of intense debate. Most researchers accept that before the arrival of anatomically modern humans, Neanderthals had adopted several transitional technocomplexes. Two of these, the Uluzzian of southern Europe and the Châtelperronian of western Europe, are key to current interpretations regarding the timing of arrival of anatomically modern humans in the region and their potential interaction with Neanderthal populations. They are also central to current debates regarding the cognitive abilities of Neanderthals and the reasons behind their extinction1, 2, 3, 4, 5, 6. However, the actual fossil evidence associated with these assemblages is scant and fragmentary7, 8, 9, 10, and recent work has questioned the attribution of the Châtelperronian to Neanderthals on the basis of taphonomic mixing and lithic analysis11, 12. Here we reanalyse the deciduous molars from the Grotta del Cavallo (southern Italy), associated with the Uluzzian and originally classified as Neanderthal13, 14. Using two independent morphometric methods based on microtomographic data, we show that the Cavallo specimens can be attributed to anatomically modern humans. The secure context of the teeth provides crucial evidence that the makers of the Uluzzian technocomplex were therefore not Neanderthals. In addition, new chronometric data for the Uluzzian layers of Grotta del Cavallo obtained from associated shell beads and included within a Bayesian age model show that the teeth must date to ~45,000-43,000 calendar years before present. The Cavallo human remains are therefore the oldest known European anatomically modern humans, confirming a rapid dispersal of modern humans across the continent before the Aurignacian and the disappearance of Neanderthals.

Link

Rapid onset of Aurignacian in Southwest France

Rapid onset of Aurignacian in Southwest France

Journal of Archaeological Science doi:10.1016/j.jas.2011.09.019

A Radiocarbon chronology for the complete Middle to Upper Palaeolithic transitional sequence of Les Cottés (France)

Sahra Talamo et al.

The Middle to Upper Palaeolithic transition is the key period for our understanding of Neanderthal and modern human interactions in Europe. The site of Les Cottés in south-west France is one of the rare sites with a complete and well defined sequence covering this transition period. We undertook an extensive radiocarbon dating program on mammal bone which allows us to propose a chronological framework of five distinct phases dating from the Mousterian to the Early Aurignacian at this site. We found that the Mousterian and Châtelperronian industries are separated from the overlying Protoaurignacian by a gap of approximately 1000 calendar years. Based on a comparison with Upper Paleolithic sites in Europe we see an overlap in the ages of Châtelperronian industries and Aurignacian lithic assemblages, which are usually associated with Anatomical Modern Humans, which is consistent with an acculturation at distance model for these late Neanderthals. The Proto and Early Aurignacian appear contemporaneous indicating that this transition was rapid in this region. Anatomically Modern Humans are present at the site of Les Cottés at least at 39,500 cal BP roughly coincident with the onset of the cold phase Heinrich 4.

Link

mtDNA and ethnic differentiation in East Africa

mtDNA and ethnic differentiation in East Africa

From the paper:

The pattern observed in East Africa (with the exception of the Khoisan-related Hadza and Sandawe populations), which combines a high level of within-population diversity with strong genetic structure among populations, suggests the occurrence of periodical episodes of admixture in these populations, separated by periods of isolation and genetic drift. Indeed, the observation of high levels of diversity within populations could be due to long-term large effective population sizes maintained in East Africa. In this case, however, little genetic structure between populations should be expected, since there would be little opportunity for genetic drift to act. Alternatively, gene flow can produce high within population diversity, and in the present case, it could also account for the extensive sharing of haplotypes and haplogroups observed between the Nyangatom and the Daasanach, as well as with other populations.

This seems like a very clever observation: substantial gene flow and a large effective population size would be inconsistent with population structure, as the different populations would be homogenized and drift would not be able to differentiate them. Long-term lack of gene flow, on the other hand, would not explain the sharing of haplotypes between populations, as each population would develop its own distinctive genetic signatures over time. Thus, the simplest explanation for the observed pattern is that gene flow has indeed occurred (accounting for the sharing of haplotypes), but that it was not continuous (accounting for the fact that populations are, after all, substantially differentiated).

From the paper:

The intermediate linkage disequilibrium (LD) found in East Africa (Tishkoff et al., 1996) in contrast with Europe (high LD) and Sub-Saharan Africa (low LD, Tishkoff & Kidd, 2004; Conrad et al., 2006), could be due to such admixture events, more frequently occurring in this region compared to other Sub-Saharan populations. Substantial levels of gene flow among Nilo-Saharan, Afro-Asiatic and Niger-Congo populations from Tanzania have already been inferred by Tishkoff et al. (2007a) and our results suggest that these gene flows could have occurred in a larger region extending up to Southern Ethiopia.

Indeed, in the absence of recent admixture, the East African populations would exhibit similar levels of LD with Sub-Saharan Africans., or even lower, as the indigenous East Africans are arguably older than those of the interior of the continent. The fact that they exhibit higher LD (intermediate between Europe and Sub-Saharan Africa) can be explained by admixture, i.e., the fact that they have inherited long stretches of DNA from the parental populations in each admixture event, and that time since that event has not been sufficiently long to cause the decay of these chunks into smaller pieces.

And, from the conclusions of the paper:

The high diversity in East Africa was interpreted as a sign of an ancient origin. However, our results might indicate that this high diversity could also come from a particular history of recent migrations and admixture promoted by the pastoralist societies that dominate in the region.

Note, that an East African origin of mankind is still the best hypothesis on palaeoanthropological and simply geographical grounds. However, the high genetic diversity found in East Africa does not necessarily reflect the antiquity of that population, but rather its history of repeated admixture by peoples of different origins.

There are two alternative hypotheses for why East Africans accumulated so much genetic diversity:

1. They are the oldest population, and have been accumulating genetic diversity for the longest period of time
2. They are substantially admixed with very divergent components (e.g., Semites, Nilo-Saharans, Cushitic speakers, and so on)

A not-so-bad example would be to compare them with other known population sources in the world, e.g., Anatolia, from where multiple waves of humans entered Europe in Paleolithic and Neolithic times. Many would agree that such movements took place, but it would be incorrect to see the population of Anatolia as a little-altered descendant of its earliest inhabitants, as the current genetic diversity observed there is -at least in part- the result of the settlement of the region by peoples from the Balkans, Central Asia, Levant, and even Western Europe.

Ann Hum Genet. 2009 Aug 25. [Epub ahead of print]

Genetic Evidence for Complexity in Ethnic Differentiation and History in East Africa.

Poloni ES, Naciri Y, Bucho R, Niba R, Kervaire B, Excoffier L, Langaney A, Sanchez-Mazas A.

Summary

The Afro-Asiatic and Nilo-Saharan language families come into contact in Western Ethiopia. Ethnic diversity is particularly high in the South, where the Nilo-Saharan Nyangatom and the Afro-Asiatic Daasanach dwell. Despite their linguistic differentiation, both populations rely on a similar agripastoralist mode of subsistence. Analysis of mitochondrial DNA extracted from Nyangatom and Daasanach archival sera revealed high levels of diversity, with most sequences belonging to the L haplogroups, the basal branches of the mitochondrial phylogeny. However, in sharp contrast with other Ethiopian populations, only 5% of the Nyangatom and Daasanach sequences belong to haplogroups M and N. The Nyangatom and Daasanach were found to be significantly differentiated, while each of them displays close affinities with some Tanzanian populations. The strong genetic structure found over East Africa was neither associated with geography nor with language, a result confirmed by the analysis of 6711 HVS-I sequences of 136 populations mainly from Africa. Processes of migration, language shift and group absorption are documented by linguists and ethnographers for the Nyangatom and Daasanach, thus pointing to the probably transient and plastic nature of these ethnic groups. These processes, associated with periods of isolation, could explain the high diversity and strong genetic structure found in East Africa.

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A different look at the Olympic Medal Count

A different look at the Olympic Medal Count

The Athens Olympics are now over and Greece won 16 medals. The best-performing nations, according to the official medal count are the United States, China, Russia, Australia and Japan. A different look at the medal count of the Olympics comes from the Australian Bureau of Statistics which has compiled a world ranking based on population per gold medal. The Bahamas, Norway, Australia, Hungary and Cuba lead this ranking, with Greece placing 8th. At the bottom of the table, Syria, Mexico, Colombia, Nigeria and India.

Dutch Hair Color Preferences

Dutch Hair Color Preferences

Gentlemen prefer blondes, women go for black

5 August 2004

AMSTERDAM — Dutch men prefer blondes and over half of Dutch women want to be blond or blonder than their present shade, particularly in the summer, according to research published Thursday.

The study carried out by research bureau Blauw Research for shampoo manufacturer Andrelon also found that women find men with dark hair more attractive.

Some 71 percent of the 535 people, aged 18 to 55, polled said they were satisfied or very satisfied with their own hair colour. Men were more satisfied with their hair colour than women.

Two out of five women were natural blondes and a slightly higher number were brunettes. The same applies to the men, though more men than women were black haired. Red hair was the rarest colour, Novum Nieuws reported.

Several women polled no longer to know what their original hair colour was.

About half of the women said they coloured their hair regularly, with 35 percent admitting to using dye. Half of the women polled have used highlights to make their hair appear blonder.

Some 10 percent put their faith in nature, relying on the sun to make their hair blonder.

The survey found that men — more so than women — believe blond hair makes a person look younger.

Women, on the other hand, were more in favour of men with dark hair, with just 17 percent of females questioned saying blond men were very attractive.

[Copyright Expatica News 2004]

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