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Monthly Archives: September 2012

The Maasai: rich ancestry, lactase persistance and low cholesterol

Maasai warriors jumping (cc by javic)
There is a new paper at the Public Library of Science on the genetics of the Maasai with emphasis in diet-related aspects:

Kshitij Wagh et al., Lactase Persistence and Lipid Pathway Selection in the Maasai. PLoS ONE, 2012. Open access ··> LINK [doi:10.1371/journal.pone.0044751]

Abstract

The Maasai are a pastoral people in Kenya and Tanzania, whose traditional diet of milk, blood and meat is rich in lactose, fat and cholesterol. In spite of this, they have low levels of blood cholesterol, and seldom suffer from gallstones or cardiac diseases. Field studies in the 1970s suggested that the Maasai have a genetic adaptation for cholesterol homeostasis. Analysis of HapMap 3 data using Fixation Index (Fst) and two metrics of haplotype diversity: the integrated Haplotype Score (iHS) and the Cross Population Extended Haplotype Homozygosity (XP-EHH), identified genomic regions and single nucleotide polymorphisms (SNPs) as strong candidates for recent selection for lactase persistence and cholesterol regulation in 143–156 founder individuals from the Maasai population in Kinyawa, Kenya (MKK). The non-synonmous SNP with the highest genome-wide Fst was the TC polymorphism at rs2241883 in Fatty Acid Binding Protein 1(FABP1), known to reduce low density lipoprotein and tri-glyceride levels in Europeans. The strongest signal identified by all three metrics was a 1.7 Mb region on Chr2q21. This region contains the genes LCT (Lactase) and MCM6 (Minichromosome Maintenance Complex Component) involved in lactase persistence, and the gene Rab3GAP1 (Rab3 GTPase-activating Protein Catalytic Subunit), which contains polymorphisms associated with total cholesterol levels in a genome-wide association study of >100,000 individuals of European ancestry. Sanger sequencing of DNA from six MKK samples showed that the GC-14010 polymorphism in the MCM6 gene, known to be associated with lactase persistence in Africans, is segregating in MKK at high frequency (~58%). The Cytochrome P450 Family 3 Subfamily A (CYP3A) cluster of genes, involved in cholesterol metabolism, was identified by Fst and iHS as candidate loci under selection. Overall, our study identified several specific genomic regions under selection in the Maasai which contain polymorphisms in genes associated with lactase persistence and cholesterol regulation.
The study actually has two elements of interest for my point of view, on one side it is the dietary aspects of Maasai genetics underlined in the title and the abstract but then there is a more generic element of understanding the relevant population genetics with the help of STRUCTURE,  reflected in fig. 1 but better addressed in the supplemental materials (Appendix S1).
The Maasai as product of 6 ancestral populations
K=6 is what STRUCTURE indicates as clear best fit (lowest log probability of fit) in a no-admixture model and all the six reconstructed ancestral populations are all present in them (unlike what happens for example with the CEU sample of European ancestry):

From Appendix S1 – click to expand
CEU: European-Americans (USA), ASW: African-Americans (USA)
LWK: Luhya (Kenya), MKK: Maasai (Kenya), YRI: Yoruba (Nigeria)

We can see that the influence of West Eurasian genetics (teal) appears to be almost nil in Africa, although the Maasai (MKK) have some (c. 2%), probably infiltrated via Ethiopia, Somalia or Sudan.
West African genetics (pink) are slightly more influential in the Maasai but only c. 10%.
Instead the Maasai display four different East African specific “ancestral populations” of which two are larger and the other two smaller in the sampled populations:
  • The yellow component is almost exclusive of the Maasai (69%), with some very minor penetration in other populations.
  • The green component is more outstanding among the Luhya (32%), reaching barely 5% among the Maasai.
  • The brown component is again almost exclusive of the Maasai (12%), with some individuals apparently displaying it as very dominant.
  • Finally, the purple one is almost exclusive of the Maasai but at much lower frequecies (3%). However it is also dominant in a few individuals.
The fact that the Maasai show obviously marked individual variance at levels not apparent in other populations, and that this variance includes some smaller “mystery” components, seems to mean that they are in ongoing or very recent admixture with other populations (maybe other Maasai clans of distinctive origin, maybe other pre-Bantu East African peoples). It indicates that there is still a lot to research in the Population genetics of East Africa, what requires of extensive new sampling among the many diverse small ethnicities of the Upper Nile and nearby regions.
Yes to milk, no to cholesterol
The other, more central aspect of this study is the localization of specific genomic regions or even alleles that guarantee that this pastoralist people can largely live off the milk produced by their cows and, quite interestingly, not to have circulatory problems because of the associated excess cholesterol.
The authors detected the following regions as very clearly under selection (several approaches being convergent in their detection):

Fig. 5

The first of these regions, in chromosome 2, seems particularly long and selected for both lactase persistence (the ability to digest lactose as adult) and low cholesterol, according to this paper. 
The region in chromosome 7 regulates the enzyme Cytochrome P450, related to oxidation processes in metabolism of lipids, steroids, drugs and toxins, probably also regulating cholesterol.

See also in this blog:

I also recommedn Ethio Helix blog, generally quite informative in all things African and genetic.

 
 

Yet another dolmen found and dug at Orereta (Basque Country)

A dolmen was found in the area of Txoritokieta (Orereta, a.k.a. Rentería, Gipuzkoa) and excavated by the Arazandi Society of Sciences. Other four megalithic burials are known in the same area. 
It is a simple dolmen (without entrance gallery), with the gate oriented to the SE and built with slabs reinforced by a circular perimeter of stones. The structure also includes a slab acting as floor and was covered by a tumulus of earth and stones.
Sources[es]: S.C. Aranzadi, Pileta.

See also: searcher of megaliths and prehistorical monuments in Gipuzkoa[es/eu].

 

La Bastida de Totana (Spain) may have been largest city in Bronze Age mainland Europe

Location of La Bastida in the context of El Argar culture (source)
Arguable I guess because it will be susceptible to further research for example in the Castro do Zambujal  (Torres Vedras, Portugal) or in the El Argar culture area itself but that is what the current archaeological team has claimed through a press release (h/t Pileta).
According to the researchers, La Bastida[es] de Totana (Murcia) was back in the day the largest city in all mainland Europe, next only to some Minoan cities of Crete. 
On first read it may sound to exaggeration but, after all, they have pushed forward the age of foundation of La Bastida and hence of El Argar culture to c. 2,200 BCE, some three or four centuries before El Argar proper… what means an older age than the founding of the Mycenaean cities (Mycenae, Athens, Thebes…), which are not older than c. 1600 BCE. 
The civilizations of Los Millares and the already mentioned Zambujal (culture of Vila Nova de Sao Pedro), both in Iberia, are still older (c. 2600 BCE) but now La Bastida de Totana stands between these Chalcolithic civilizations and the Bronze Age ones, whose paradigm is El Argar, of which La Bastida may have been seed.
Hill of La Bastida (Totana, Murcia) – source: La Bastida[es].
Excavated ruins
Honoring its name (etymologically related to “bastion”) La Bastida was a heavily fortified city spanning four hectares on top of an strategical hill. Its 2-3 meter thick stone walls are the oldest known of its kind in all Europe, although they have precedents in West Asia:

The fortification consisted of a wall measuring two to three metres
thick, built with large stones and lime mortar and supported by thick
pyramid-based towers located at short distances of some four metres. The
original height of the defensive wall was approximately 6 or 7 metres.
Until now six towers have been discovered along a length of 70 metres,
although the full perimeter of the fortification measured up to 300
metres. The entrance to the enclosure was a passageway constructed with
strong walls and large doors at the end, held shut with thick wooden
beams. 

One of the most relevant architectural elements discovered is the ogival
arched postern gate, or secondary door, located near the main entrance.
The arch is in very good conditions and is the first one to be found in
Prehistoric Europe. Precedents can be found in the second city of Troy
(Turkey) and in the urban world of the Middle East (Palestine, Israel
and Jordan), influenced by the civilisations of Mesopotamia and Egypt.
This indicates that people from the East participated in the
construction of the fortification. These people would have reached La
Bastida after the crisis which devastated their region 4,300 years ago.
It was not until some 400 to 800 years later that civilisations like the
Hittites and Mycenaeans, or city-states such as Ugarit, incorporated
these innovative methods into their military architecture.

Recreation of La Bastida city (source)
Pythos burial, style surely imported from Greece
Contextualizing
For what I have read on the matter, I understand that El Argar culture, often imagined as a centralized state, would have been divided into three regions or smaller realms, of which the area of Totana and Lorca (roughly modern Murcia region) would be the northern one. 
From the pushing backwards of the age of La Bastida I deduce that the this region may well have been the origin of El Argar civilization itself, which surely absorbed Los Millares manu militari later on, maybe leading to the founding of El Argar city as new capital between the two realms, much like Memphis was founded in Egypt after the unification of the Upper and Lower kingdoms. 
I am here speculating a bit of course – feel free to correct me if you know better. 
Besides of El Argar cultural area, the influence of this state may have extended through much of Southern and Eastern Iberia, possibly into all the areas colored in this map:
Possible wider area of influence of El Argar civilization, earliest Bronze (source)
Of course the areas in blank were not empty but had other cultures, in some cases also outstanding civilizations, like VNSP in the following map:
Middle Bronze in Iberia (anti-copyright by me – same one as Sugaar)
In the La Bastida dedicated site you can find much more information in Spanish language, as well as photos, about this fascinating site, which was maybe the navel of much of Europe four thousand years ago. Another complementary source for this entry has been the dedicated page of Murcia regional government. Thanks to both.
 

Neolithic ‘calendar’ found in Vietnam

The artifact, marked with ordered dots and strips that may well represent the lunar cycle, was found in Nguom Hau Cave (Na Hang District, Tuyên Quang province, Northern Vietnam). 

A similar artifact was discovered in 1985 not far away: Na Cooc Cave (Thái Nguyên province). 

The calendar has been estimated to be from c. 4000 years ago. 

The stone tool was found in a tomb marked with 14 large stones laid at a length of 1.6m. Bones were found under the stones but no skull was found, with Chung guessing that the skull may have decayed due to the humidity in the cave.


A number of other stone tools were buried with the corpse.

The dig also produced much other information from the Iron Age (3.0-3.5 Ka BP), Late Neolithic (4.0-4.3 Ka BP) and a deeper and very thick Early Neolithic layer consisting of many polished stone axes and other tools.
Together with other findings, the evidence mounts for inhabitation from at least 8000 years ago in this area. 

Source: Viêt Nam News (via Pileta).

 
2 Comments

Posted by on September 27, 2012 in archaeoastronomy, archaeology, East Asia, Neolithic, SE Asia, Vietnam

 

Portugal: ‘austerity’ may close Côa Park

Côa engravings (CC by Henrique Matos)
Côa Valley is not just a fantastic natural park in the NE of Portugal but also one of the key areas of European Prehistory, hosting the famous mural engravings the Upper Paleolithic.
The Portuguese government decided on Tuesday (Sep. 25) to suspend its existence and is considering its complete dismantling, as part of the austerity efforts imposed by the IMF and the EU. 
The cost of the park is 1.4 million euros yearly.
No cuts are known to affect the Armed Forces for example, even if Portugal has not known enemies anymore and could do with just some patrol ships. 
Source: RTP Noticias[por] (via Pileta).
 

September 26 – closed because of general strike

For what they were… we are adheres to the general strike against social expending cuts, which simply put: kill people and destroy societies. This strike has been called separately in the Basque Country, Greece and Galicia – as far as I know.
I may comment further if there are important news in my other blog, For what we are… they will be, but expect no activity whatsoever in this blog until Thursday. 
Sorry for whatever inconvenience.
Closed!
September 26 – General Strike
For labor and social rights
Let’s face the cuts, the reform and the impositions!
 
6 Comments

Posted by on September 25, 2012 in blogging, general strike

 

Chalcolithic Iberian script?

La Zarcita vessel
This is not really news but something that has been around since the 1950s but that, because of the attitude of (excessive?) scientific prudence of the researchers has never been known except to a few specialists. 
A few years ago however, Dr. Ana María Vázquez Hoys, re-discovered the inscribed artifacts in the Museum of Huelva, proposing that maybe there was a Chalcolithic script in Southern Iberia some in the 4th or 3rd millenium BCE, some two millennia before it is commonly accepted that writing arrived to Iberia, via the Phoenicians (but with scripts that have at best a very oblique connection with the Phoenician abjad).
Personally, I just learned about them today, thanks to an archaeology series in state TV, that is almost always worth watching in spite of the horrible schedule (early in the morning).
Of course the inscribed artifacts are isolated anomalous findings, much as is the case with the even older Vinča symbols from the Neolithic Balcans, but they are well documented and the inscriptions, whatever they are or mean, are very real.
One of the inscribed artifacts is a round ceramic piece with a canalization along its diameter it, arguably resembling a vagina and initially described as “arrow polisher” but that could well have some sort of ritual purpose. This object originated in San Bartolomé de la Casa (Huelva province).

San Bartolomé inscribed “vulva”

Tracing of the signs above by Vázquez Hoys

The other object is a legged tray or vessel, also made of local clay with pyrite granules, only shows a few characters. It has the same Megalithic period chronology and was found in La Zarcita (Huelva prov.) It probably had ritual use as well.

Outline of La Zarcita vessel, showing the inscriptions (by Vázquez Hoys)

Main online source: UNED page on the matter by Dr. Vázquez Hoys[es].