Could Neolithic 'cultural fitness' have caused a male reproductive bottleneck?

Earlier this year, a paper published in Genome Research sequenced a sample of globally diverse Y chromosome data and found a bottleneck within modern Y chromosome lineages that occurred about 8 - 4 ka. The results of this study suggest that at this time the effective population size of females was 17 times higher than that of males.

Since the timing of the bottleneck coincides with periods of rapid cultural and technological change, including numerous agricultural innovations, the researchers claim that the reduction in male reproductive diversity could be a signal that fewer males were reproducing. A potential explanation for this would be that the men were competing culturally for women, rather than mate choice being random or driven by biological fitness.

If this hypothesis holds up after further genetic and archaeological research, this would be a good example of cultural practices driving large scale genetic changes in ancient human populations.