A recent bottleneck of Y chromosome diversity coincides with a global change in culture

Abstract

It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50–100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192–307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47–52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males.

Investigating mitochondrial DNA relationships in Neolithic Western Europe through serial coalescent simulations

“…18) and no population structure in any of the four groups. 5 Moreover, the panmictic population model proposed would need to be compared against alternatives (eg, ref.…”

“…Noteworthy, some N UP -N N combinations imply a population decline that clearly contrasts with previous studies based on modern DNA data, which have inferred female effective population size growth in Europe during the Holocene. 18 However, we were not constrained to simulate population expansion, since we did not consider modern DNA data in our analyses. Moreover, a Holocene population decline in Europe corroborates recent Y chromosome data 18 and various archeological evidence support demographic fluctuation of Neolithic populations.…”

“…18 However, we were not constrained to simulate population expansion, since we did not consider modern DNA data in our analyses. Moreover, a Holocene population decline in Europe corroborates recent Y chromosome data 18 and various archeological evidence support demographic fluctuation of Neolithic populations. 19,20 Our results indicate that a simple panmictic population model can account for the mtDNA differentiation observed between European HG and Early/Middle Neolithic farmers; a larger proportion of the HG-Gurgy explored parameter space failed to reject panmixia.…”

Men’s status and reproductive success in 33 nonindustrial societies: Effects of subsistence, marriage system, and reproductive strategy

“…In humans, the reproductive benefits of status reached their peak in premodern states and empires, where sultans, kings, and emperors could control access to a large number of women (17). Studies of the Y chromosome suggest a large increase in male reproductive skew with the rise and spread of agriculture 10,000 y ago (18), and common Y haplotypes can be traced to the lineages of high-status rulers such as Genghis Khan (19,20). In modern industrial societies with monogamy and low fertility, several studies find that male fertility associates modestly with wealth, largely due to higher childlessness among poorer men (21)(22)(23)(24).…”

“…Positive selection on status may have increased significantly with domestication of plants and animals, due to greater material wealth inequality, institutionalized leadership, and male reproductive skew (17,18,39). This "egalitarianism hypothesis" can be tested with quantitative estimates of the relationship between male status and reproductive success (RS) in contemporary foragers compared with nonforagers.…”