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?

The real 'paleodiet' was rich in carbs

Beets and acorns is the real paleofood... or at least part of it.

From Science Nordic (h/t Pileta):

Stone Age hunters liked their carbs

Analyses of Stone Age settlements reveal that the hunters were healthy and would gladly eat anything they could get their hands on, including carbohydrates – contrary to the modern definition of the Paleolithic, or Stone Age diet.

The Stone Age hunter’s food contained large amounts of protein from fish, lean mean, herbs and coarse vegetables and has formed the basis of one of today’s hottest health trends: the paleo diet.

The modern version of the Stone Age diet excludes foods rich in carbohydrates. This exclusion of carbs is based on the idea that Stone Age hunters didn’t have access to bread, rice or pasta.

But is it true that Stone Age hunters and gatherers didn’t eat any carbohydrates at all?

Sabine Karg, an external lecturer at Copenhagen University’s Saxo Institute, specialises in archaeobotany. She says that Stone Age hunters, unlike many followers of the modern Stone Age diet, joyfully munched away at carbs when the opportunity presented itself.

“Carbohydrates have been part of their diet. In flooded settlements from the Palaeolithic and Mesolithic periods, traces of roots and seeds from various aquatic plants and wild grasses have been found.”

... continue reading at Science Nordic. 

Acorn "bread" was widely used in Atlantic Europe until recently because cereals were not always reliable enough in this humid climate. Beets soon became a common agricultural produce.

'Lucy' could climb like chimps, some modern humans too

The transition from an arboreal lifestyle to a purely terrestrial one was never finished: some modern humans who live natural lifestyles in the forests of Earth still climb more or less like a chimpanzee, i.e. "walking" vertically.

This seems more a matter of acquired flexibility of certain calf muscles than anything else (although I imagine that a small complexion, which reduces weight, may also help a lot).

Emphasis is made therefore in that australopithecines like Lucy, who had clear anatomical adaption to walk like we do, could still be using trees almost at whim: there's no such a binomial disjunctive between walking and climbing and wide compromises can be made.

Vivek V. Venkataraman, Tree climbing and human evolution. PNAS, 2010. Open access → LINK [doi: 10.1073/pnas.1208717110].

Abstract

Paleoanthropologists have long argued—often contentiously—about the climbing abilities of early hominins and whether a foot adapted to terrestrial bipedalism constrained regular access to trees. However, some modern humans climb tall trees routinely in pursuit of honey, fruit, and game, often without the aid of tools or support systems. Mortality and morbidity associated with facultative arboreality is expected to favor behaviors and anatomies that facilitate safe and efficient climbing. Here we show that Twa hunter–gatherers use extraordinary ankle dorsiflexion (>45°) during climbing, similar to the degree observed in wild chimpanzees. Although we did not detect a skeletal signature of dorsiflexion in museum specimens of climbing hunter–gatherers from the Ituri forest, we did find that climbing by the Twa is associated with longer fibers in the gastrocnemius muscle relative to those of neighboring, nonclimbing agriculturalists. This result suggests that a more excursive calf muscle facilitates climbing with a bipedally adapted ankle and foot by positioning the climber closer to the tree, and it might be among the mechanisms that allow hunter–gatherers to access the canopy safely. Given that we did not find a skeletal correlate for this observed behavior, our results imply that derived aspects of the hominin ankle associated with bipedalism remain compatible with vertical climbing and arboreal resource acquisition. Our findings challenge the persistent arboreal–terrestrial dichotomy that has informed behavioral reconstructions of fossil hominins and highlight the value of using modern humans as models for inferring the limits of hominin arboreality.

See also: Science Daily. H/t Pileta[es].

Native American archaeological findings

Stone Pages' Archaeonews includes in its latest newsletter a number of interesting references to new findings on Native American Prehistory:

The Morehead Circle (Ohio)

This ritual enclosure of the intriguing Hopewell culture, which is being dug now, is dealt in detail at Ohio Archaeology Blog → link 1, link 2.

Pig Point funerary rituals (Maryland)

These would be part of the Adena culture, precursor of Hopewell, and this site in coastal Maryland has yielded not just evidence of them but layers and layers of associated artifacts, with the oldest being as early as 10,000 BP (most are from 5000 to 1000 BP however).

Early Native American tribes engaged in reburial rituals. Every year, 10 years, or more, a group would gather the remains of their dead and commit them to a common burial ground.

Iroquois tribes were noted for their reburial rituals as were the Nanticoke who took their ancestors’ remains with them when they moved to Pennsylvania from the Eastern Shore.

Ossuaries held the the dead whether nothing but skeleton or fresher remains. But the bodies were intact, or mostly so. The difference at Pig Point is that all the bones were smashed, broken on purpose. And so were thousands of artifacts such as fancy Adena points, beads, gorgets, and other items. All broken into bits.

→ Capital Gazette.

Ohio calumets reveal wide exchange networks

The site of Tremper Mound (Ohio) has been known for a century now but it was assumed that the many pipes found there were carved from local stone. That has been now demonstrated to be mostly wrong: only less than 20% of the pipes were made from local materials, instead 65% were carved in flint clay from Northern Illinois and 18% in catlinite from Minnesota.

→ e! Science News.

4000 years old weapons from Sinaloa

50 km north of Mazatlan (Sinaloa, Mexico) lays the rock art  site of Las Labradas. Not far from there, at La Flor del Océano, archaeologists have now discovered spearheads, knives and other tools made of stone. 

→ Fox News.

Asian Homo erectus may have used fire and clothes

That is what a media news is claiming on this New Year's night: that Peking man, an early member of a long diverged branch of Humankind (understood as the genus Homo in full) may have already used artificial fire and leather clothing.

While this may seem quite necessary for any kind of people living as far North as Beijing (roughly the latitude of Philadelphia) the possibility that our cousin's adaption to cold was biological, by means of retaining ancestral fur instead of our techno-cultural way, was open.

Now some researchers from the Chinese Academic of Science's Institute of Palaeoanthropology and the University of Toronto think that they have some evidence that could support the use of fire and clothing.

As far as I can tell no study has been published yet, so I'm telling from the media alone.

Sources: Live Science, MSBCN - h/t Unreported Heritage News.

PS - Happy 2013 to all.