Wednesday, November 30, 2016

1st Millennium Canary Islander DNA (Ordenez et al, 2016)

Bernard Sécher comments on a genetic study of Canary Islanders prior to Modern European contact. "ADN ancien d'une population aborigène de l'île de El Hierro dans les Canaries"

He lays out the details, which you'll need since the paper is pay-per-view.

Ferdinand and Isabella receive captive Guanches

These results present a bit of a dilemma for conventional wisdom. Not only are these 61 individuals before the Spanish missions, the Punta Azul individuals are nearly maternally fixed H1-16260. It also appears that haplogroup R1b is native to El Hierro, or at least predates Hispanization. Of course there are also the expected, typical Berber haplogroups. (once again we see a strong relationship between R1b and H1)

No evidence yet suggests habitation before the European Early Bronze Age and the last major immigration event would have been pre-historic Berbers. Between the Berber influx and the Colonial Period, the islands were sometimes visited by maritime powers, but the islands were home to people with relatively little contact between each other or the outside world.

So this leaves several possibilities as to how and when the ancestry of the cave people of El Heirro formed. One is that Punic, Greek or Roman settlers or merchants left a paternal mark on the natives and that this was specifically the introduction of R1b-M269 in the largest part. There could also be unrecorded contact between Medieval Spain and the islands. That's a difficult case to make.

A second possibility is that the presence of R1b among North African Atlas Berbers was at one time much more pronounced than it is now and is reflected in the founding Berber population of the islands. That's a good possibility.

More conservative potteries with geometries and solar motifs [via Gevic]

A third possibility, and in keeping with the autosomal results and diversity of male lines, is that the islands were already inhabited before the Berber influx and was also genetically monolithic and Atlantic-like, something like if Ireland was invaded by Berbers. It's important to remember the time-frame in which the islands were first populated in a meaningful way (sometime in the 2nd millennium) and also where they are in relation to Western Morocco.

Pintaderas Canarias (Gobierno de Canarias)

These three possibilities are not exclusive. The really big news is that this has implications for how modern uni-parental markers of the contemporary inhabitants are viewed. Maybe this will encourage Canary men to get the full y-chromosome tested.

Genetic studies on the prehispanic population buried in Punta Azul cave (El Hierro, Canary Islands)

Highlights

•: A total of 61 samples from Punta Azul were analyzed for ancient DNA.
•: Success rate: molecular sexing 88.5%, uniparental markers 90.16%, STR 45.9%.
•: There is a complete fixation of the H1-16260 mtDNA lineage.
•: Y-chromosome results show the presence of three lineages: E-M81, R-M269, and E-M33.
•: Matrilineality could explain the behaviors in maternal and paternal lineages.

Abstract

The aim of this study was to establish the genetic studies of the population from one of the most important known aboriginal funerary spaces of the island of El Hierro (Canary Islands), the Punta Azul cave, which harbors remains of 127 individuals. Sixty-one adult tibiae were examined, 32 left and 29 right. Radiocarbon dating yields an antiquity of 1015–1210 AD. We have obtained an overall success rate of 88.5% for the molecular sexing, and of 90.16% for the uniparental markers. Short tandem repeats (STR) profiles were also possible for 45.9% of the samples. This performance is a consequence of the good conservation of the bones in their archaeological context. The mtDNA composition of the sample is characterized by the complete fixation of the H1-16260 lineage. These results can be explained by a mixture of consecutive founding events, a bottleneck episode at the beginning of the colonization and/or as a consequence of genetic drift. Paternal lineages were also affected by these processes but in a less acute way. These differences lead us to propose social behaviors as an explanation for this difference. The maternal transmission of the lineages, mentioned in ethnohistorical sources of the Archipelago, could be an explanation. These results could be in agreement with endogamous practices, but the autosomal STR results indicate a relative high diversity. These results have allowed us to characterize the Punta Azul cave population and see the way in which geographical isolation, the process of adaptation and specific social behaviors affected the aboriginal population of the Island.