The XX Factor

8,000 Years Ago, Only One Man Had Children for Every 17 Women

The advent of agriculture led to a genetic bottleneck 8,000 years ago. 

Photo by Christopher Furlong/Getty Images

Bad news for anyone who touts the idea that our ancient ancestors had it all figured out: Scientists have discovered evidence that, during the Stone Age, only one man passed on his DNA for every 17 women. That’s right, guys. Living like our ancient ancestors means having as little as a 1-in-17 shot of reliably getting laid. 

Danielle Paquette at the Washington Post explains:

Researchers recently uncovered a sharp decline in genetic diversity in male lineages across the world during the Stone Age. The study’s authors hypothesized that material gains made through early agricultural success — a proxy for wealth — gave smaller groups of related men the reproductive upper hand for generations.


“Men who had more wealth and power might have had more to offer to women,” said co-author Melissa Wilson Sayres, an Arizona State University professor who studies sex-biased biology. “Their sons and grandsons could have been more successful in the same way.”


(“More to offer” is one way to think about it, but the cynic in me wonders how much choice women could really exercise in societies that were so strictly patriarchal that a few wealthy men shut all the other men out of the sexual marketplace so effectively.)

In short, the research suggests that the men who managed to have the most babies—whose babies managed to survive to adulthood and have more babies and pass their genes down to the present day—were the ones who were really good at agriculture. It’s worth noting that most evolutionary psychology proponents (or “paleofantasists” as biologist Marlene Zuk calls them) imagine that the “true” nature of humans developed during our pre-agricultural, hunter-gatherer phase. It’s difficult to imagine that true human nature is found in the heart of the caveman, when it’s likely that a few successful early farmers just crushed the competition in the genetic lottery. 


The real takeaway here is to be skeptical of the notion that our sexual and social habits are as strongly genetically programmed as evo-psycho proponents believe. As Francie Diep at Pacific Standard writes, “As more thousands of years passed, the numbers of men reproducing, compared to women, rose again.” Far from being robots who are acting out unchanging genetic scripts, we are creatures who experience periods of dramatic change—and those changes, in turn, change our genes. 

The other takeaway: to be grateful we live in an age where it’s harder for a few powerful men to snatch up all the women for themselves. That sounds terrible for both men and women.