April 3, 2015

19 Ka BP old mtDNA H from Cantabria

Jean Lohizun points me to this new study by the EHU-UPV paleogeneticist team, which reviews the ancient DNA evidence from the Cantabrian strip (or "fringe" as they call it) and, most importantly announces the oldest confirmed mtDNA H to date: belonging to an individual from El Mirón cave (Ramales, Cantabria, bordering the Basque Country), which is assigned to earliest Magdalenian culture and dated to 19,000 BP.

Update (Apr 24): the genetic findings of El Mirón were first published (in Spanish) in: M. Hervella et al., El ADN mitocondrial de los cazadores-recolectores de la región cantábrica: nueva evidencia de la cueva de El Mirón, Revista Española de Antropología Física - Vol. 35 (2014). I could not find an online reference but I have a copy of the article thanks again to Jean.

Concepción de la Rúa et al., Ancient DNA in the Cantabrian fringe populations: A mtDNA study from Prehistory to Late Antiquity. Quaternary International, 2015. Pay per viewLINK [doi:10.1016/j.quaint.2015.01.035]


The present mtDNA study on human remains of fourteen archaeological sites from Cantabria, Basque Country and Navarra provided a diachronic overview from Paleolithic–Mesolithic to Late Antiquity period of some communities settled in the Cantabrian fringe. Ancient DNA studies in European human remains indicated a genetic discontinuity between the hunter–gatherers and later populations. However, some of the mtDNA lineages found in the Cantabrian fringe in Paleolithic–Mesolithic times persist in present-day populations.

The mtDNA variability observed in hunter–gatherers and farmers in Europe denoted a complex pattern for the Neolithic transition, occurring along several different routes into and across Europe. The mtDNA lineages found in the Cantabrian fringe indicated that the dispersion of Neolithic farmers had a different genetic impact in this area with respect to Central and Mediterranean regions of Europe. The differences in mtDNA variability were also apparent after the Neolithic, as shown by the genetic distance between the Chalcolithic populations from the Cantabrian fringe and the Bell Beaker Culture (BBC) populations of Central Europe. 

It must be mentioned that they seem to have forgotten the thesis of Marie Lacan[fr], which reported mtDNA H in Linatzeta cave (Basque Country, Epipaleolithic) and Franchthi cave (Greece, Meso-Neolithic transition), among other more recent aDNA sequences. See here for my English language synthesis.

Otherwise they list all the sequences considered in their paper in table 1:

Annotations by Maju: red: El Mirón (new sequence), orange: other Paleolithic or Epipaleolithic sequences

After including Linatzeta (Lacan 2011), we get the following frequencies in the Eastern Cantabrian sub-region (Basque Country + Cantabria) for pre-Neolithic times:
  • H: 4/6=2/3=67%
    • H-CRS (H1 surely): 33%
    • H6: 16%
    • H*: 16%
  • U5: 2/6=1/3=33%
    • U5*: 16%
    • U5b1: 16%
Notice anyhow that if we choose to draw a line between Cantabria and the Basque Country, then we get a sharp contrast: 
  • Cantabria: 100% H
  • Basque Country: 67% U5 + 33% H* (or even an illusory 100% U5 if we use only the table above, ignoring Lacan's data)
Does this apparent sharp contrast make any sense? Well, one possible interpretation comes from carefully taking into account the data we have on Iberian Solutrean and Magdalenian, which indicates that:
  1. South Iberian (from Valencia to Portugal) Solutrean is heavily influenced by the Gravettian substrate (otherwise "pure Solutrean" is restricted to two caves), configuring a unique facies sometimes called Gravetto-Solutrean.
  2. South Iberian Gravetto-Solutrean, probably in its way to Portugal, strongly affected the Upper Paleolithic of Northwest Africa, being a decisive force in the Iberomaurusian or Oranian genesis. Backflows can't be discarded because of the innovation of tanged and winged arrow points, which may have been inspired by North African Aterian technology.
  3. The Portuguese branch of this Gravetto-Solutrean was the actual source (via Salamanca) of Asturian Solutrean, unlike what happened in Cantabria and the Basque Country, directly influenced by Aquitaine. 
  4. In the subsequent Magdalenian there might have been an expansion eastward of the Asturian population, because the facies divide moves to the east (so we have a Cantabro-Astur facies and a Basque facies).
In addition to that, it may be worth considering the issue of North African genetic influence in the Western Third of the Iberian Peninsula, which incidentally and irregularly includes Cantabria but not the Basque Country. Also Chandler et al. 2005 reported high frequencies of mtDNA H (and low of U) in Epipaleolithic Portugal.

I guess that other interpretations are possible such a more subtle cline or patchy distribution but I would not discard this hypothesis, which in essence proposes that Solutrean and Magdalenian were in general dominated by U5 but this did not affect (at least not very intensely) most of Iberia, nor surely other regions like Italy or Eastern Europe, where we see haplogroups that are not U5 (Sunghir's and Karelian H, Italian mysterious HV, etc.)

This implies that the main redistribution of mtDNA H in Europe, that part organized around H1 (which also includes H3 and various H*) actually happened mostly in the Neolithic from areas like Portugal. However we know nearly nothing about the Atlantic pre-Neolithic DNA North of the Bidasoa River (some of which could also be H, particularly R*-CRS reported in Britain) so multiple sources are possible. The huge blank of data corresponding to the Western French State and also Atlantic Islands, etc. is crying for a comprehensive sampling, and not just for mtDNA. 

Neolithic Basque mtDNA is unlike what is found in Continental Europe

The authors pay limited attention to the issues relative to Paleolithic and dedicate most of the paper to analyze the Basque ancient mtDNA in contrast to other comparable data from elsewhere in Europe. This is synthesized in fig. 2:

Fig. 2. Multidimensional Scaling analysis (MDS), based on a Fst genetic matrix calculated from the frequency distribution of the mtDNA haplogroups of different populations [Neolithics (green), Chalcolithics (purple), Late Antiquity (red), present-day Near East and northern Caucasus (orange) and Europeans (black)]. Abbreviations for present-day populations in Europe: Eastern Mediterranean (MdE), Central Mediterranean (MdC), Western Mediterranean (MdW), Northeast Europe (NE), NortheCentral Europe (NC), Northwest Europe (NW), Southeast Europe (SE) and Alps (ALP). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.).

Notice that all the ancient mtDNA from the so-called "Cantabrian Fringe" in this graph is from the Basque Country (Navarre included), often outside of the Cantabrian strip and rather from the Upper Ebro basin. Notice also that the all the Chalcolithic data belongs to military contexts from the Ebro Valley and are probably therefore not representative of the overall Basque region, although they may represent well the Upper Ebro in that period (more influenced apparently by Mediterranean inputs of Cardial affinity).

Also I already discussed all this (and more) quite in depth in my dedicated entry of 2013

The authors argue that Germany's Bell Beaker samples (BBC) are not quite similar to the Basque ancient and modern pools, what is true if you are nit-picky enough, but they share the same common tendency in PC1 towards modernity. In contrast all other Neolithic samples are clearly non-modern European and must have been largely suffered by replacement in the Chalcolithic or later periods.

PS- I forgot to mention that apparently Paabo and co. had already sequenced this very same specimen in 2013, yet they have not published anything for unknown reasons, some think that ideological ones. It's of course possible that they do have good reasons but two years is a long time to await publication really, we the people, who pay their salaries and budget with our extreme economic pains, expect reliability from our well-paid researchers.