**Acknowledgements**

farmer, Chalcolithic, Bronze Age, and present-day populations from the Cantabrian fringe, Europe, and the Near East. This analysis shows the differentiation between the two huntergatherer populations from Central Europe and Scandinavia (**Figure 6**). It has been proposed that the mtDNA variation of these groups indicates a genetic discontinuity between the huntergatherers and later populations in these two geographic regions [13, 14, 50, 51]. However, this suggested discontinuity is not so obvious in the case of the hunter-gatherers from the Cantabrian fringe who separated from those of Central Europe and Scandinavia in this analysis

With regard to the European Neolithic populations, the heterogeneity observed in the mtDNA haplogroup frequency variation is revealed by their position on the two-dimensional plot of the MDS analysis (**Figure 6**). On the one hand, a group of populations (Near East, Central Europe, Hungary, and Eastern Pyrenees) with high-frequency values for haplogroup N is separated from the other Neolithic populations. On the other hand, heterogeneity is also apparent within the Mediterranean area, with a Neolithic population of Southern France being closer to present-day populations in the Near East, due to its high frequency for haplogroups J and U, whereas the Neolithic populations from the Iberian Peninsula (Catalonia and the Cantabrian fringe) show lower frequency for those haplogroups (J and U) (**Figure 6**). The genetic distances observed between the European Neolithic groups suggest a different genetic impact of the Neolithic farmers from the Near East on Central Europe, Mediterranean Europe, and the Cantabrian fringe. These data support a random dispersion model for

Neolithic farmers, with different impact on the various geographic regions [9].

the genetic substrate of the BBC\_CE groups came from the BBC\_Iberian groups [16].

mainly related to the Beaker phenomenon.

With respect to the Chalcolithic prehistoric groups included in the analysis (BBC\_CE, BBC\_ Iberian, CA\_Iberian, CA\_Cantabrian and Aramo), those with BB culture (BBC\_CE and BBC\_ Iberian) are differentiated from the rest. On the other hand, the distance between the BBC groups of Central Europe and the Iberian Peninsula is due to both the greater persistence of Paleolithic U5 lineages in the BBC\_Iberian group and the higher frequency of Neolithic lineages T and J in the BBC\_CE group. This differentiation suggests that the relation between these two Chalcolithic groups (BBC\_CE and BBC\_Iberian) is only cultural but not genetic, supporting the study [18] about the Beaker phenomenon and genomic data from Europe, who reject the hypothesis that

Regarding the Chalcolithic populations without BB culture, CA\_Iberian and CA\_Cantabrian are genetically close to one another, with El Aramo being further from them due to the high frequencies of haplogroups H and I3. These Chalcolithic groups are not distant from their Neolithic ancestor populations, although they are distant from the present-day populations of these regions (**Figure 6**), which could be attributed to a post-Neolithic population restructuring [20]. In view of the results obtained, it can be inferred that the influence of the Neolithic period on the local groups was complex, and its result could generate the existence of Chalcolithic groups in the Iberian Peninsula with genetic and cultural differences, with the latter being

The human group of El Aramo Mine, without artifacts associated with BBC, shows some peculiarities. Its chronology expands from the Chalcolithic period to the Early Bronze Age,

[9, 17] (**Figure 6**).

124 Mitochondrial DNA - New Insights

This work was supported by the Basque Government to Research Groups of the Basque University System (IT1138-16) and grant from the Spanish Ministry of Science and Innovation (GCL2016-79093/P). We are grateful to Miguel Angel de Blas Cortina, Director of the archeological intervention in El Aramo Mine, for providing archeological data and fruitful discussion.
