A recent bottleneck of Y chromosome diversity
coincides with a global change in culture
A change in social structures that increased male variance in offspring number may explain the results, especially if male reproductive success was at least partially culturally inherited (Heyer et al. 2005)....an increased male-specific variance among demes, perhaps enhanced by increased sex-biased migration patterns (Destro-Bisol et al. 2004; Skoglund et al. 2014) and male-specific cultural inheritance of fitness.
https://www.academia.edu/download/38112982/ms-2015-Karmin_et_al_-_Genome_Res_Y_chromosome_paper.pdf
Wang CC, Huang Y, Wen SQ, Chen C, Jin L, Li H. 2013a. Agriculture driving male expansion in
Neolithic Time. http://arxiv.org/abs/1311.6857. arXiv preprint arXiv:1311.6857
We found that most major paternal lineage expansions coalesced in Neolithic Time. The estimated effective population sizes through time revealed strong evidence for 10- to 100-fold increase in population growth of males with the advent of agriculture. This sex-biased Neolithic expansion might result from the reduction in hunting-related mortality of males.
https://arxiv.org/abs/1311.6857
Our phylogeny shows bursts of extreme expansion in male numbers that have occurred independently among each of the five continental superpopulations examined, at times of known migrations and technological innovations.
Second, in
sub-Saharan Africa, two independent E1b-M180 lineages expanded
~5 kya (Supplementary Fig. 14a), in a period before the numerical
and geographical expansions of Bantu speakers, in whom E1b-M180
now predominates22. The presence of these lineages in non-Bantu
speakers (for example, Yoruba and Esan) indicates an expansion predating the Bantu migrations, perhaps triggered by the development of ironworking23
The earlier of these times,
5.5 kya, is associated with the origin of the Bronze Age Yamnaya cul-
ture. The Yamnaya have been linked by aDNA evidence to a massive
migration from the Eurasian Steppe, which may have replaced much
of the previous European population24,25; however, the six Yamnaya
with informative genotypes did not bear lineages descending from or
ancestral to R1b-L11, so a Y-chromosome connection has not been
established. The later time, 4.8 kya, coincides with the origins of
the Corded Ware (Battle Axe) culture in Eastern Europe and the
Bell–Beaker culture in Western Europe26.
Potential correspondences between genetics and archeology in
South and East Asia have not been investigated as extensively. In South
Asia, we detected eight lineage expansions dating to ~4.0–7.3 kya and
involving haplogroups H1-M52, L-M11, and R1a-Z93 (Supplementary
Fig. 14b,d,e). The most striking were expansions within R1a-Z93,
occurring ~4.0–4.5 kya. This time predates by a few centuries the
collapse of the Indus Valley Civilization, associated by some with the
historical migration of Indo-European speakers from the Western Steppe into the Indian subcontinent27.
the lineage expansions seem to have followed innovations that may have elicited increased variance in male reproductive success29, innovations such as metallurgy, wheeled transport, or social stratification and organized warfare.
https://www.nature.com/articles/ng.3559
A simultaneous decline of Y-chromosomal diversity dating to the Neolithic has been observed across most extant Y-haplogroups (64), possibly due to increased conflict between male-mediated patrilines (65). We view that changes in social structure (e.g., an isolated mating network with strictly exclusive social norms) could be an alternative cause but would be difficult to distinguish in the underlying model parameters.
Since social kinship systems influence patterns of genetic diversity (13, 42, 48, 74), it is likely that several different kin systems existed in third millennium BCE central Europe. The highly diverse genetic profiles (both nuclear and Y-chromosomal) of early CW suggest a different social organization to late CW and BB, whose Y chromosome pattern is indicative of strict patrilineality. This suggests that different cultural groups, in addition to using various forms of material culture and mortuary practices, likely also conformed to different ideologies as expressed in their mating pattern and/or social organization. This is supported by the finding of completely nonoverlapping Y chromosome variation between the partially contemporaneous late CW and BB, indicating a large degree of paternal mating isolation between these two groups, even when found at the same site (e.g., Vliněves).
https://www.science.org/doi/full/10.1126/sciadv.abi6941
To illustrate the power of YMCA, we show that the analysis of ancient Y-chromosome lineages can help to resolve Y-chromosomal haplogroups. As a case study, we focus on H2, a haplogroup associated with a critical event in European human history: the Neolithic transition. By disentangling the evolutionary history of this haplogroup, we further elucidate the two separate paths by which early farmers expanded from Anatolia and the Near East to western Europe.
https://www.nature.com/articles/s41598-021-94491-z
the loss of diversity of Neolithic Y-chromosomes lineages with the arrival of Steppe-like ancestry at the beginning of the 3rd millennium BCE15,18,19,20.
With the arrival of Steppe-related ancestry ~ 5 kya, incoming YHGs such as R1a and R1b would largely replace many of the older, “Neolithic” YHGs, such as G2, T1a, and H219, and although H2 was never found in particularly high frequencies among Neolithic individuals, we expect that its diversity was also greatly reduced, and many sub-lineages were potentially lost altogether.
https://royalsocietypublishing.org/doi/epdf/10.1098/rstb.2021.0414
Mobile hunter–gatherer societies are extensive multilevel fission–fusion societies characterized by fluid, open composition and movement of individuals and family units among residential groups [31,–34,46,47]. Information can move among groups of humans far more rapidly than for other hominoids [48,49]. At some point—a first key set of transitions—hominins were able to interact cooperatively with individuals from other groups,and the portal for the viral flow of cultural information began to open. Rapid communication of information would be further enhanced by high mobility enabled by bipedality and a more terrestrial niche. Interactions among fluid groups would have intensified interdependent ratcheting in culture,brains, communication and cooperation [34,50,51], potentiating subsequent transitions in hominin evolution. This hominin pattern stands in contrast to the constricted sociality of chimpanzees, gorillas and orangutans [34,44]; we argue, however,that it has some intriguing similarities to that of bonobos.
The past 10 ka have seen a 1000-fold increase in population size [165]. From 8 to 4 ka in Africa, Asia, Europe and the Middle East there was a strong bottleneck in the Y-chromosome in which the effective population size ofwomenisupto17-fold that of men,which is consistent with cultural transmission of fitness, i.e. changes in social organization that increased variance in the offspring number of men [188–190]. It has been suggested that the cultural change involved was a widespread switch to patrilineal kin groups and competition between these groups [190], a switch that may have come about due to agriculture, private property rights, and emergent political complexity [191–194]. At approximately 4–3ka, a rate increase has been calculated to have occurred with much faster exponential, or super-exponential population growth[186,187]. A key cultural shift that may have caused demo-graphic changes was the proliferation of social norms that recognize private property rights. The accumulation of private property usually accompanies sedentarization, which requires storage, and it has the potential to heighten reproductive com-petition in men due to differential property ownership and polygynous marriages that favour the reproductive success of wealthier men, as found in sedentarized hunter–gatherer societies, big man societies, and chieftanships [195].Prior to the adoption of agriculture, wealth inequalities were likely limited to a few sedentary societies of hunter–gatherers, such as those of the Pacific Northwest Coast [196]. Sedentarization and the creation of private property rights over resources may be the result of either agriculture (which involves storage, agricultural tools, other people’s labour, and land tenure) or foraging practices that rely on fixed resources e.g. salmon runs. Storage usually emerges as a response to seasonality and unpredictably [197]. Once established, it potentiates the emergence of inequality because it effectively creates property that can be used by an individual or clique to gain political leverage over others, and it supports greater population density and sedentary aggregations [197–199]. The emergence of agriculture, which began about 12 ka, appears to have played a role in increasing population growth(through fertility increases associated with sedentarization and cultivation) [200], possibly in a boom-and-bust pattern [201]. In order for agriculture to emerge as a novel subsistence strategy,it required a critical mass of hunter–gatherers to adopt changes in social norms that led to privatization of resources and failure of the levelling mechanisms that disengage people from property accumulation [202–204]. Once farming was adopted by a critical mass, groups of farmers would ultimately out-reproduce foragers due to fertility increases, thus spreading the farming and private property cultural package [203].
https://royalsocietypublishing.org/doi/epdf/10.1098/rstb.2021.0414
The initial differentiation location of N1a2a-F1101 and its most closely related branch, N1a2b-P43, a major lineage of Uralic-speaking populations in northern Eurasia, is likely the west part of northeast China. After ∼4 thousand years of bottleneck effect period, haplgroup N1a2a-F1101 experienced continuous expansion during the Chalcolithic age (∼ 4.5 kya to 4 kya) and Bronze age (∼ 4 kya to 2.5 kya) in northern China. Ancient DNA evidence supported that this haplogroup is the lineage of ruling family of Zhou Dynasty (∼ 3 kya-2.2 kya) of ancient China.
Discussion: In general, we proposed that the Bronze Age people in the border area between the eastern Eurasian steppe and northern China not only played a key role in promoting the early state and civilization of China, but also left significant traces in the gene pool of Chinese people.
https://www.frontiersin.org/articles/10.3389/fgene.2023.1139722/full
The Zhou dynasty was the last dynasty of the Bronze Age in central China. Interestingly, N1a2b-P43, the mostly close branch of N1a2a-F1101, is the founder paternal lineage of the Uralic populations in northern Eurasia (Rootsi et al., 2007; Karmin et al., 2015; Ilumäe et al., 2016). The initial divergence of these two clades should have been between modern northern China and Siberia. Haplogroup N1a2a-F1101 is one of the major paternal lineage of modern Chinese, especially the Han Chinese (Liu et al., 2022; Tao et al., 2023).
https://www.frontiersin.org/articles/10.3389/fgene.2023.1139722/full
The model presented argues that the human capacity for spiritual transcendence may have been an evolutionary development related to the temporary loss of the sense of self that can occur during human orgasm. Recent research on the neuroendocrine mechanisms involved in human sexuality and in spirituality show that the human orgasm and experiences of spiritual transcendence appear to be built on similar neurobiological processes that involve a temporary eradication or loss of the sense of the self.
Sex and the Evolution of Spirituality
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