August 10, 2011

Lots of news

Stories of interest are accumulating at my "to do" folder these days. While I may later on deal with some of them in detail, here there is a synthesis:


Prehistory & archaeology:

Unusual hanging decorative/utilitarian retouching stone (left) found at Irikaitz (Zestoa, Gipuzkoa, Basque Country). The item has been dated to c. 25,000 years ago, what may well make it Aurignacian (Gravettian is of very late arrival to the area).

Hanging objects of stone are rare and most belong to later periods (cf. Praileaitz of Magdalenian era).

··> Pileta de Prehistoria[es], video at EiTB[es].

Neanderfollia[cat] mentions that life expectancy seems to have increased dramatically in the Upper Paleolithic. ··> Daily Mail, also discussed at GNXP.

Bronze Age pottery at Hala Sultan Tekke (Larnaca, Cyprus),  indicates mayor contacts with Mycenaean Greece, including import of pottery. Also goddess figurine found, which may be local. ··> Cyprus Mail.

Claims of grave goods indicating when old men became powerful in Traisen Valley (Austria). The study compared burials of the 2200-1800 BCE period (Late Chalcolithic) with the 1900-1600 BCE one (Early Bronze Age). Both elderly women and men gained burial goods  in the later period but men elder were buried with copper axes (quite useless but surely a prestige item), which appears more valuable than the regular axes of young and adult men. ··> Live Science.



Genetics:

A new paper on autsomal variation of Basques in comparison with other populations (by Kristin L. Young, freely accessible at PubMed) is something I want to dedicate some more time when I have it. By the moment:

Fig.2 - Multidimensional Scaling plot of genetic distance (click to expand) - Basques: black dots

Neanderfollia[cat] also mentions a research on several full human genomes that estimates that Humankind may have shrank suddenly c. 100,000 years ago, at the same time that the various populations scattered through the world. They also claim that genetic exchange however continued (with Bushmen too) until c. 20 Ka ago. It raises my eyebrows so high that they have melted with my other hair but must mention anyhow. ··> Daily Mail.


Dienekes mentions a couple of somewhat interesting open access papers:

Bigger heads (and eye sockets) meant  to process dimmer light, not to increase intelligence, research claims. ··> SD.

Jaw bones shaped mostly by diet, not genes. Narrow jaws indicate soft cooked diet, broad ones a harder type of food. Researched on two isolated Native American populations but IMO lacks controls and it could be argued that the differential evolution is genetically programmed in each population regardless of diet. ··> SD.

IQ-specific genes too diluted to be found ··> Medical Press.

Math ability is inborn (but don't count on the genes to be found anytime soon) ··> SD.

Endurance gene found. A gene exists that makes us non-Olympic or marathon-level quality meat. ··> SD.

Chimpanzees are spontaneously generous and don't like demanding friends ··> SD.

7 comments:

  1. "A new paper on autsomal variation of Basques in comparison with other populations (by Kristin L. Young, freely accessible at PubMed) is something I want to dedicate some more time when I have it. By the moment:"

    Looking at the image (I've read the article briefly) there are some issues I don't understand:

    -Is the figure trying to represent real genetic distances between populations? It's notable that there's much more genetic diversity within the Iberian peninsula (even in the Basque country itself) than in Europe.
    -Distances between Europeans can be as large as or more than between Europeans and Moroccans, or Europeans and Turks.
    -How can it be possible, that two countries located very far the one from the another, appear to be genetically the same?
    -Some populations and their genetic distances are difficult to believe (Scots? Catalans? Portuguese?).

    If the samples are too small or taken in just one place some bizarre results can appear. The huge genetic distances between Europeans may reflect isolation and/or inbreeding in some of them.

    If the article was trying to prove the Basques aren't descended from neither N.Africans nor populations from the Caucasus, I think it's fine; after all it's unexpected that Basques have different origins than those of their neighbours (what may have been expected if 7.000 years ago proto-Georgians migrated to the Basque country and eventually became the Basques). But definitely nothing more.

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  2. I'll deal with all this later.

    Anyhow, sample sizes can be very distorting: you see dots and imagine similar samples but they might be 1000 people vs. 5. But I haven't but overlooked at the paper so I cannot say as of yet.

    Still this kind of Basques (and also Iberians) having more apparent internal diversity (genetic distance) while the bulk of Europeans clusters in a small area has shown up in other studies before.

    For example in a paper I commented in 2008, on mtDNA, Basques and Iberians (but not Catalans) behaved similarly to how they do on this graph.

    In Bauchet 2007 also (fig. 3) Basques and "Spanish" behave somewhat similarly in the PC2, specially Basques. "Spanish" were all from Valencia, what maybe helped to Finns and Greeks/Armenian/Jews define the PC1 instead of being so influenced by Iberian variation.

    It's an interesting issue that I hope to be able to address properly with more time. It may be indicative of the great diversity that hosts SW Europe and, if so, a clear indicative of very deep (Paleolithic) roots.

    (Note: yet in the structure sorting algorithm, fig. 4, Basques rather soon, K=5, achieved strong homogeneity in a single distinct cluster).

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  3. "Anyhow, sample sizes can be very distorting: you see dots and imagine similar samples but they might be 1000 people vs. 5. But I haven't but overlooked at the paper so I cannot say as of yet."

    I know... in fig. 4 (I've already seen this study) there's only one French!! In addition to low samples, if you take all people from just only one town or city you can lose a lot of information. I think that's specially true for Moroccans.

    "For example in a paper I commented in 2008, on mtDNA, Basques and Iberians (but not Catalans) behaved similarly to how they do on this graph."

    I'd say the case of Catalans (and Scots) is likely due to low samples in this study at least. It's possible some Iberians may look more distant because they have some North African admixture in them, specially those from the south?

    Here's another study: Iberians do not seem to be so diverse:

    http://undeception.com/wp-content/uploads/2008/08/200808142008.jpg

    More:
    http://www.corrupt.org/drupal/files/images/europe_variation.jpg
    http://blogs.discovermagazine.com/gnxp/files/genmapeuropeA.jpg

    http://anthropologynet.files.wordpress.com/2008/09/genetic-geographic-separation-of-european-populations.jpg


    "It's an interesting issue that I hope to be able to address properly with more time. It may be indicative of the great diversity that hosts SW Europe and, if so, a clear indicative of very deep (Paleolithic) roots. "

    If that's the case, I odn't undesrtand why we can't see the same with the French, giving the fact most paleolithic peoples seem to have lived in France instead of Iberia.

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  4. Good counter examples.

    One thing is clear: you can't just sample 12 people in a single town and expect them to represent a whole state like France or Spain. You need to sample several hundred in many different places.

    The French are almost always undersampled and sampled in a single location, For instance Lyons or Paris. With Spaniards the case varies more but generally when they show up as homogeneous, I suspect that it is because of narrow sampling.

    There was one (rather uninteresting) study on Spaniards (but not Portuguese nor Galicians nor Basques nor any area near the Basque Country), where it was apparent that, while Asturians and Valencians clustered with Central Castilians, Catalans and Andalusians did not but tended towards Italy (and Catalans also towards Northern Europe - North Africa was not contrasted either).

    But in the end samples and representation methods make a lot, because we are projecting a complex genetic landscape on a simplified "map", for example the two dimensions of the PCA or the various, sometimes ghostly, clusters of structure algorithms.

    They are a bit like different views of a multidimensional perspective, and all are needed to see the whole thing, not just one or two.

    "I'd say the case of Catalans (and Scots) is likely due to low samples in this study at least".

    Have you checked? The data is probably in the paper or supp. materials.

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  5. The sample of Catalans seems to be from http://www.ncbi.nlm.nih.gov/pubmed/10929236. It's pay per view, so no idea, but I think it is almost impossible for a too small sample to become the main polarity of PC2, as the Catalan sample does.

    It is indeed somewhat strange on first sight that Catalans are the opposite in this PC2 axis of nearly all transmediterranean populations (Morocco, Egypt, Georgia - even Turkey, Greece and Tuscany rank rather low) but it'd make total sense ONLY if the Cardium Pottery expansion in Catalonia was non-colonial.

    This is somewhat confirmed by the rankings of Murcia, where there was no Cardium Pottery at all (AFAIK) and should retain at least some of their Epipaleolithic Azilian-like population (instead Valencia was strongly colonized by Cardium Pottery peoples and ranks like Bosnia, right at the origin of that migration).

    It's a possible interpretation.

    The other axis, PC1, is between Navarre and Scotland and seems more to describe relations within Europe (Pyrenean vs Nordic, so to say). Not only West Basques rank somewhat high in the Pyrenean side of this axis but also Cantabrians and Moroccans (pooled?).

    Notice that this axis runs rather at the 0.5 value in the Catalan vs. Transmediterranean PC2 axis, so it is quite a bit into the "Catalan" side of things all along (though not all the populations mentioned, as is the case of Moroccans).

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  6. I have now written a separate entry for Young 2011 (the paper on Basque genetics) and therefore, please post all new comments on this matter there. Thanks in advance.

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  7. Coming back to the Math entry:

    "Do children born with better number sense have an easier time learning to count and to understand the symbolic nature of numbers? Or it is just that children born with less accurate number sense may end up avoiding math-related activities before they develop competency?"

    My opinion is that some children simply learn (with some effort and support) to be very good at low-level math, but then don't improve much - because they don't ever approach math from a more theoretical viewpoint. Others have exceptional analytical capabilities from the get-go, and employ these effortlessly and often without being taught for mundane math tasks (if they feel like it). Many will find algebra and geometry boring (and may not score very high), but in later years (15 or so), will understand calculus and linear algebra easily without ever knowing why others struggle.

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