Ancient tsunamis of Europe

In red the tsunami sediments
Measures: height of the wave at each location

A huge tsunami probably hit the northern parts of Doggerland (the emerged landmass of what is now the North Sea) some 8000 years ago. The evidence from this catastrophic event, which probably affected the earliest inhabitants of NW Europe in a catastrophic way comes from an underwater formation off the Norwegian coast known as Storegga, which was partly demolished by the force of the giant wave, as well as from sedimentary layers at various coastal locations. The wave reached more than 20 meters at the Shetlands, where it left a 30cm-thick revealing layer.

Another possible tsunami may have affected the Southwestern coasts of Iberia in the 7th century BCE. This is currently being researched and could be related to the collapse of the semi-mythical city of Tartessos.

Sources: Meteoweb[it], Paleorama[es] (→ link 1, link 2).

Early Neolithic burials found near Istanbul

Pendik, a suburb of Istanbul on the Asian coast of the Bosporus, has produced a Neolithic settlement dating to c. 8500 years ago, including houses, burials and various tools (spoons, needles, axes). 

One of the Pendik burials

Source: Press TV.

Châtelperronian was made by Neanderthals

Contrary to some rumors and some skepticism, the archaeology and radiocarbon chronology appear to support only Neanderthals as the material authors of the first "mode 4" stone industry of Western Europe: the Châtelperronian.

They still allow for it, and especially the novel behavior of production and use of durable ornaments (on bone mostly), to have been influenced by the penetration of Homo sapiens.

Jean-Jacques Hublin et al., Radiocarbon dates from the Grotte du Renne and Saint-Césaire support a Neandertal origin for the Châtelperronian. PNAS 2012. Open access → LINK [doi: 10.1073/pnas.1212924109 ]

Abstract

The transition from the Middle Paleolithic (MP) to Upper Paleolithic (UP) is marked by the replacement of late Neandertals by modern humans in Europe between 50,000 and 40,000 y ago. Châtelperronian (CP) artifact assemblages found in central France and northern Spain date to this time period. So far, it is the only such assemblage type that has yielded Neandertal remains directly associated with UP style artifacts. CP assemblages also include body ornaments, otherwise virtually unknown in the Neandertal world. However, it has been argued that instead of the CP being manufactured by Neandertals, site formation processes and layer admixture resulted in the chance association of Neanderthal remains, CP assemblages, and body ornaments. Here, we report a series of accelerator mass spectrometry radiocarbon dates on ultrafiltered bone collagen extracted from 40 well-preserved bone fragments from the late Mousterian, CP, and Protoaurignacian layers at the Grotte du Renne site (at Arcy-sur-Cure, France). Our radiocarbon results are inconsistent with the admixture hypothesis. Further, we report a direct date on the Neandertal CP skeleton from Saint-Césaire (France). This date corroborates the assignment of CP assemblages to the latest Neandertals of western Europe. Importantly, our results establish that the production of body ornaments in the CP postdates the arrival of modern humans in neighboring regions of Europe. This new behavior could therefore have been the result of cultural diffusion from modern to Neandertal groups. 

Fig. 1. Calibrated ages and boundaries calculated by using OxCal 4.1 (37) and IntCal09 (36). The Grotte du Renne ages are in black and are compared with the Saint-Césaire human [Neanderthal] bone date in red. Asterisk indicates anthropogenically modified bones. The results are linked with the (NGRIP) δ18O climate record.

Importantly, it is also confirmed that Grotte-du-Renne (Arcy-sur-Cure, Burgundy) is one of the last Chatelperronian, and therefore surely Neanderthal, pockets in  Western Europe, co-existing with Aurignacian North-East and South-West of it, what is suggestive of this latter culture, probably the first settlement by Homo sapiens, expanding to SW Europe via Italy rather than Germany.

Finally, according to our results, the CP Neandertals of the Grotte du Renne, Saint-Césaire, and Les Cottés clearly postdate the earliest likely modern humans remains documented in western Europe (43) and largely overlap in time with the early Aurignacian in the Swabian area (44) and in southwestern France (42).

 

Fig. S1. Geographical distribution of the Châtelperronian assemblages and location of the three main Châtelperronian sites discussed in the text.

Hat tip to Linear Population Model.

Eye color, face shape and perception of trustworthiness

An old popular Galician song said:

Ollos verdes son traidores...
azules son mentireiros,
os negros e acastañados son firmes e verdadeiros.

Translated:

Green eyes are treacherous...
blue ones are deceitful,
the black and brown ones are loyal and truthful.

Just word of a silly mariner song? Intriguingly science confirms now, in a way, part of this perception (at least for blue and brown eyes).

But notice please that it is the precisely the perception what is being confirmed: people seem to perceive blue eyes in general as somewhat less trustworthy. The study says nothing about people with blue eyes being untrustworthy in fact, just that we tend to distrust them more than people with brown eyes.

Karel Kleisner et al., Trustworthy-Looking Face Meets Brown Eyes. PLoS ONE 2013. Open access → LINK [doi:10.1371/journal.pone.0053285]

Abstract

We tested whether eye color influences perception of trustworthiness. Facial photographs of 40 female and 40 male students were rated for perceived trustworthiness. Eye color had a significant effect, the brown-eyed faces being perceived as more trustworthy than the blue-eyed ones. Geometric morphometrics, however, revealed significant correlations between eye color and face shape. Thus, face shape likewise had a significant effect on perceived trustworthiness but only for male faces, the effect for female faces not being significant. To determine whether perception of trustworthiness was being influenced primarily by eye color or by face shape, we recolored the eyes on the same male facial photos and repeated the test procedure. Eye color now had no effect on perceived trustworthiness. We concluded that although the brown-eyed faces were perceived as more trustworthy than the blue-eyed ones, it was not brown eye color per se that caused the stronger perception of trustworthiness but rather the facial features associated with brown eyes.

So the authors conclude that it is not eye color but associated face shape what drives untrustworthiness because the phenotype associated with blue eyes is more angular, less rounded, at least for males:

Figure 2. Shape changes associated with eye color and perceived trustworthiness.
Thin-plate spline visualizations of the way face shape correlates with eye color (a–f) and trustworthiness (g–i). Generated face shapes of blue-eyed woman (a) and brown-eyed woman (c) compared to average female face (b). Generated face shapes of blue-eyed man (d) and brown-eyed man (f) compared to average male face (e). Generated face shapes of untrustworthy-looking man (g) and trustworthy-looking (i) man compared to average male face (h). The TPS grids of perceived trustworthiness for women are not shown because shape analysis did not meet statistical significance. The generated facial images (a–f) were magnified 3x for better readability.

They claim that they found no correlation with facial shape for women but I find in the image above almost exactly the same pattern for men and women and not only what they detected: notably the blue eyed people (both genders) and the less trusted men all have in my opinion:

• Smaller eyes
• More serious (defiant, analytic, unsympathetic) expression
• Proportionally broader face or at least jaws

In general the faces to the left look significantly colder, less empathic, a perception that blue eyes can only enhance.

The authors ponder if there is a phenotype linkage disequilibrium associating face and eye color, what seems plausible. But then go on speculating about sexual selection and what not. 

In this sense Razib has an interesting critical analysis questioning if selection is behind the blue eye incomplete sweep in West Eurasia or Europe. If I understand him correctly he seems to suggest, never clearly naming it, that blue eye may have been favored because of the associated skin pigmentation trait, a key adaptive value in the dark winters of Europe and very especially the northern half of it.


Update: is this a peculiarity of Central Europe or the Czech Republic?

A reader sent me an email in which it was questioned if this association is peculiar of the Czech Republic, where the study was performed, and can't be extended for example to Britain. Examples of soft-faced blue-eyed Britons mentioned were Hugh Grant and Alec Baldwin (I'm not sure if Baldwin is such a good counter-example but Grant is for sure one such case). 

I find it a very good criticism and hope that entices debate.



See also: Causes of skin and hair color variance in Europeans remain undetermined.

Ancient DNA comparison supports continuity in the Basque Country

Before we get too ecstatic, I must clarify that the ancient DNA is Neolithic from Santimamiñe (previously discussed here) and that the information released so far (local conference with press coverage) is not just way too little but also very imprecise. 

Dr. Marian Martínez de Pancorbo presented these findings yesterday in Gernika, capital of Urdaibai district where Santimamiñe cave is located, as culmination of a genetic study of modern locals from rural municipalities immediate to the famous cave (Kortezubi, Nabarniz, Ereño and Gautegiz-Arteaga). What she said is all but clear: the residents of past and present keep relation among them but...

... the lineages are not exactly the same because they are gradually lost in the course of generations. It is something normal, that also happens with surnames, which change along time. 

She announced that her team will publish soon the results in two prestigious publications from the USA. Naturally I can't wait to get my hands on them (with the additional personal thrill of part of my family, albeit the patrilineage, coming from that area, just a few kilometers from said cave) but will have to wait.

Martínez de Pancorbo is also working in the other extreme of the Basque Country, seeking to find if the massacred inhabitants of Metal Ages La Hoya town, surely the areal capital for some time, are directly related to those of nearby Biasteri (Laguardia).

Sources[es]: El Correo, Pileta. 

From previous related entries:

On the La Braña double burial:

pre-Neolithic mtDNA in Northern Iberia (several sources)

On the second unmistakable discovery of ancient mtDNA H in Europe, Cantabria specifically:

Some ancient mtDNA of Basque Country and Cantabria
(each letter indicates one sequence,
Linazeta and La Braña were not known to the authors)

Actually it had already been found a bit earlier in the Basque Country (but I did not know till later) and would be later sequenced in Karelia; it's probably also found in other (Epi-)Paleolithic localities from Morocco to Russia via Britain (but some people have been in denial on this issue).

Chromosome scale evolution among Hominidae (great apes, humans)

I won't surely be able to make justice here to this most interesting but highly technical paper but mention must be done of it in any case:

Marta Farré et al., Recombination Rates and Genomic Shuffling in Human and Chimpanzee—A New Twist in the Chromosomal Speciation Theory. Molecular Biology and Evolution, 2012. Open access → LINK [doi: 10.1093/molbev/mss272]

Abstract

A long-standing question in evolutionary biology concerns the effect of recombination in shaping the genomic architecture of organisms and, in particular, how this impacts the speciation process. Despite efforts employed in the last decade, the role of chromosomal reorganizations in the human–chimpanzee speciation process remains unresolved. Through whole-genome comparisons, we have analyzed the genome-wide impact of genomic shuffling in the distribution of human recombination rates during the human–chimpanzee speciation process. We have constructed a highly refined map of the reorganizations and evolutionary breakpoint regions in the human and chimpanzee genomes based on orthologous genes and genome sequence alignments. The analysis of the most recent human and chimpanzee recombination maps inferred from genome-wide single-nucleotide polymorphism data revealed that the standardized recombination rate was significantly lower in rearranged than in collinear chromosomes. In fact, rearranged chromosomes presented significantly lower recombination rates than chromosomes that have been maintained since the ancestor of great apes, and this was related with the lineage in which they become fixed. Importantly, inverted regions had lower recombination rates than collinear and noninverted regions, independently of the effect of centromeres. Our observations have implications for the chromosomal speciation theory, providing new evidences for the contribution of inversions in suppressing recombination in mammals. 

Maybe most interesting, at least for the casual reader, is this graph:

Fig. 1.

Evolutionary history of human chromosomes superimposed on the phylogeny of great apes. Black lines within the phylogenetic tree represent the ancestral state of the chromosomes, whereas red and orange lines represent the rearranged forms. Orangutan maintains the ancestral form for orthologous chromosomes 3 and 11, whereas human, chimpanzee, and gorilla forms are derived. Orthologous chromosomes 1, 2, and 18 have been rearranged in the lineage leading to humans, whereas orthologous chromosomes 4, 9, 15, 16, and 17 are rearranged in the lineage leading to chimpanzee. Ancestral chromosome 5 has been maintained in orangutan and human but has suffered two independent inversions in chimpanzee and gorilla, respectively. Chromosome 7 has suffered one inversion, which has been fixed in gorilla, and another inversion has been fixed in the lineage leading to human and chimpanzee. Chromosome 10 underwent one inversion that was fixed in human and chimpanzee, and a new inversion fixed in gorilla. Finally, chromosome 12 has maintained the ancestral form in humans and orangutans but has undergone an inversion that has been fixed in chimpanzee and gorilla, therefore, the polymorphic state has persisted across multiple speciation nodes (gorilla–human–chimpanzee and human–chimp).

→ large original version

No changes at this scale happened in the other eight autosomes (6, 8, 13, 14, 19, 20, 21, and 22) in any of the four genera. 

Warning must be done about the timeline, which should be twice as old at least for the Pan-Homo split.

It is interesting to notice that Pan (chimpanzee) and Gorilla share a derived form of the chromosome 12, indicating that the Homininae split was not too clean, possibly with gorilla introgression into chimpanzees. 

It is also interesting to realize that orangutans (Pongo) are extremely conservative in the genome (all 22 chromosomes, what means that surely the common ancestor of all Hominidae was more similar to modern orangutans than to any other branch. 

Finally I find notable that our chimpanzee cousins are actually more evolved than us, literally, a blunt numerical truth that is strongly counterintuitive for our anthropocentric vision of biology and evolution. While us humans have conserved 15 ancestral chromosomes (almost as many as gorillas: 16), chimpanzees only conserved 11, evolving one step (red lines) 9 chromosomes (humans 6, gorillas 5) and two steps (orange lines) two chromosomes (humans and gorillas just one).



PS- On the other hand, our Homo branch has a peculiar chromosomal rearrangement that puts up quite apart from the rest of Hominidae: two ancestral chromosomes got fused into a single one (chromosome 2) in our line. This may well have been decisive in our reproductive divergence from Pan and even maybe Gorilla, crafting a very impassable biological barrier. (Not in the paper, just my afterthought).

Incidentally, a 2006 study (Wainwright 2006) claimed to have found some strong correlation between cognitive abilities (not just IQ but also other more creative aspects of the mind) and areas of chromosome 2. With the usual caution I guess it is worth mentioning here.

Frontal bulge: an almost exclusive characteristic of Homo sapiens

Even if the article is behind a paywall, the abstract is self-explanatory enough to be worth a mention:

Emiliano Bruner et al., Geometric variation of the frontal squama in the genus homo: Frontal bulging and the origin of modern human morphology. American Journal of Physical Anthropology, 2013. Pay per view → LINK [doi: 10.1002/ajpa.22202]

Abstract

The majority of studies of frontal bone morphology in paleoanthropology have analyzed the frontal squama and the browridge as a single unit, mixing information from different functional elements. Taking into account that the bulging of the frontal bone is often described as a species-specific trait of Homo sapiens, in this article we analyze variation in the midsagittal profile of the genus Homo, focusing on the frontal squama alone, using landmark-based superimpositions and principal components analysis. Our results demonstrate that anatomically modern humans are definitely separated from extinct human taxa on the basis of frontal bulging. However, there is minor overlap among these groups, indicating that it is necessary to exercise caution when using this trait alone to make taxonomic inferences on individual specimens. Early modern humans do not show differences with recent modern humans, and “transitional” individuals such as Jebel Irhoud 1, Maba, and Florisbad, show modern-like frontal squama morphology. The bulging of the frontal squama in modern humans may represent a structural consequence of more general cranial changes, or it could be a response to changes in the morphology of the underlying prefrontal brain elements. A subtle difference between Neandertals and the Afro-European Middle Pleistocene Homo sample is associated with flattening at bregma in the former group, a result that merits further investigation.

Frontal bone: the frontal squama or scales is labeled as 1
Source: Atlas of Human Anatomy.

I wonder how much this confusion between frontal squama (rising of the forehead) and browridge (facepalm!) has caused the strange theories of Trinkaus and followers?