Ancient DNA suggests the leading role played by men in the Neolithic dissemination

Abstract

The impact of the Neolithic dispersal on the western European populations is subject to continuing debate. To trace and date genetic lineages potentially brought during this transition and so understand the origin of the gene pool of current populations, we studied DNA extracted from human remains excavated in a Spanish funeral cave dating from the beginning of the fifth millennium B.C. Thanks to a "multimarkers" approach based on the analysis of mitochondrial and nuclear DNA (autosomes and Y-chromosome), we obtained information on the early Neolithic funeral practices and on the biogeographical origin of the inhumed individuals. No close kinship was detected. Maternal haplogroups found are consistent with pre-Neolithic settlement, whereas the Y-chromosomal analyses permitted confirmation of the existence in Spain approximately 7,000 y ago of two haplogroups previously associated with the Neolithic transition: G2a and E1b1b1a1b. These results are highly consistent with those previously found in Neolithic individuals from French Late Neolithic individuals, indicating a surprising temporal genetic homogeneity in these groups. The high frequency of G2a in Neolithic samples in western Europe could suggest, furthermore, that the role of men during Neolithic dispersal could be greater than currently estimated.

Mitochondrial haplogroup C in ancient mitochondrial DNA from Ukraine extends the presence of East Eurasian genetic lineages in Neolithic Central and Eastern Europe

“…7,8 Two specimens were designated as members of haplogroup H, two were members of the U clade and three shared the 16223-16298-16327 HVS1 sequence motif characteristic of the root sequence of haplogroup C. 9,10 Specimen Ya34 carried a transition at 16357, characteristic of the C4a2 subbranch of the C clade. 10 While the majority of mtDNA lineages found in the Neolithic remains from the NPR can be ascribed to the haplogroups of West Eurasian origin and are in agreement with those previously reported for prehistoric haplogroups in West Eurasia, [11][12][13][14][15][16][17][18] our finding of East Eurasian lineages is uncommon in ancient European remains and has only been observed in the neighboring populations of the Carpathian Mountains. 19,20 Haplogroup C is a derivative of the M8 subclade of the Asianspecific M clade.…”

Tracing the genetic origin of Europe's first farmers reveals insights into their social organization

“…Taken together, these findings suggest that sub-haplogroups of G2a were frequent in Neolithic populations of the sixth-fourth millennia BC across Europe. Thus, if we take Y chromosomal haplogroup I2a (and possibly I1) as proxy for a Mesolithic paternal genetic substratum in Europe, we observe a similar pattern to the changeover in the mitochondrial DNA variability, in which NRY G lineages were predominant among Neolithic farmers across Europe and I lineages became rare [38,40,[43][44][45]49,51]. While the newly discovered NRY C haplogroup suggests additional Y lineages in eastern Hungary [41], the eastern Hungarian NRY data are still too few to estimate, whether there was paternal genetic difference between the populations of western and eastern Carpathian Basin.…”

“…Y chromosome study of modern-day Europeans has suggested a post-LGM expansion from a Franco-Cantabrian refugium for clade I1, and southeast European refugium for I2a1 based on high divergence time estimates [58]. I2a has indeed been found in Mesolithic and Neolithic Central and North European hunter-gatherers [33,34,40,41], as well as in Neolithic remains of southwestern Europe [44,45]. Haplogroup I2a (and possibly I1) might represent a pre-farming legacy of the NRY variation in Europe, alongside the recently described pre-Neolithic C (M130) haplogroups in Russia and Spain [35,42].…”

“…This is predominately based on a high number of lineages attributed to the 'Neolithic package' and low frequencies of hunter-gatherers lineages, which clearly distinguish the cluster of farmers not only from hunter-gatherers of Central/North [28 -30,41] and southwestern Europe [32, 47,48], but also from Neolithic Iberian populations [44,45,47,48,50] and Central European cultures of the third/second millennia BC [39,49,51]. To exclude biases induced by potential maternal kinship within the prehistoric datasets, we also performed PCA and MDS with reduced datasets, excluding haplotypes with identical HVS-I and II sequences from the same site.…”

“…Ancient genomic studies have described the early farmers as genetically most similar to extant populations of southern Europe [31,33,40,41]. Y chromosome data from prehistoric Europeans is still scarce but relevant for our study (electronic supplementary material, dataset S20), including hunter-gatherers [33][34][35]40,42], and early farmers from Germany [38,40], eastern Hungary [41], Austria [43] and southwest Europe [40,44,45].…”