Live data from Hacker News

Analysis of DNA uncovers a rough dating scene after the advent of agriculture

psmag.com

11–20 of 93 posts

Re: Analysis of DNA uncovers a rough dating scene after the advent of agriculture

#11
post #2

Makes perfect sense to me. If you look at our culture now there is always that one male all the females in a group tend to go for. Same for males there's always that 1 mega hotie you want to meet. The only difference is even average females can have any guy they want while the same doesn't apply to guys. The advent of agriculture gave females the ability to support their children more easily without the help of males…

Right. This is not a new theory. It's well known that evolution tends to favor polygamy where females are more selective and males are more promiscuous.

What's interesting is that this apparently started after agriculture rather than before. I had previously thought that maybe hunter gatherers practiced polygamy but it faded away as we become more agricultural.

Also 17 females to 1 male is pretty absurd. Even if you look at cultures that practiced polygamy in recent history it wasn't to that extent. And even when it was practiced, it wasn't necessarily common except in the very upper class, so the average female to male ratio would have been more reasonable.

We can only speculate to what degree this might have shaped our (recent) evolution. That's a huge selective pressure on males to have traits that would lead to them being the local king or whatever they were. And everyone alive today would be descended from those people.

Re: Analysis of DNA uncovers a rough dating scene after the advent of agriculture

#13
post #10

This is not my research area. However, I can't help but the results seem to radical to me. The dip in male diversity seems far too synchronized among so many different regions / cultures. Are there examples in recorded history of sudden reductions in male diversity that lasted for multiple generations?

http://blogs.discovermagazine.com/gnxp/2010/08/1-in-200-men-... :

> ~10% of the men who reside within the borders of the Mongol Empire as it was at the death of Genghis Khan may carry his Y chromosome, and so ~0.5% of men in the world, about 16 million individuals alive today, do so. Since 2003 there have been other cases of “super-Y” lineages. For example the Manchu lineage and the Uí Néill lineage. The existence of these Y chromosomal lineages, which have burst upon the genetic landscape like explosive stars sweeping aside all other variation before them, indicates a periodic it “winner-take-all” dynamic in human genetics more reminiscent of hyper-polygynous mammals such as elephant seals. As we do not exhibit the sexual dimorphism which is the norm in such organisms, it goes to show the plasticity of outcome due to the flexibility of human cultural forms.

Re: Analysis of DNA uncovers a rough dating scene after the advent of agriculture

#14
Since a lot of early civilizations seemed to be very slave heavy I wonder if that had anything to do with it. Agriculture requires more labour which leads to more slaving. Male slaves would work the fields with less of a chance for reproduction, and the landowners/slaveowners would have their pick of the female slaves.

Re: Analysis of DNA uncovers a rough dating scene after the advent of agriculture

#15
I've suspected as much would happen during the agricultural revolution, but I did not expect such a huge disparity.

If the 51% male/female ratio did not change, then 16 out of 17 males must have either been killed, enslaved, or been left frustrated. This would imply a highly patriarchal society where the local king and his cronies are the only ones fed, and to whom you would sell your daughters to. The only other explanation would be mass infanticide of males, but to see this in multiple regions is suspect.

"It wasn't like there was a mass death of males. They were there, so what were they doing?" The article raises a very good question. In all places studied, agriculture must have favored a highly stratified society.

Re: Analysis of DNA uncovers a rough dating scene after the advent of agriculture

#17
My 16 yr old is interested in pursuing this field (not sure what to call it - 'Genetic Anthropology'?). Can anyone recommend online resources to help a newbie get the lay of the land? Or in-person resources (talks, exhibits, clubs etc.) near Palo Alto CA ??

Re: Analysis of DNA uncovers a rough dating scene after the advent of agriculture

#18
"In more recent history, as a global average, about four or five women reproduced for every one man"

Correct me if I'm wrong, but isn't this the same as saying one man, on average, will father a child with about four or five different women? I suppose given the timescale being discussed, "recent history" may mean the last few centuries, but this average still sounds very high to me.

Re: Analysis of DNA uncovers a rough dating scene after the advent of agriculture

#20
post #12

If you guys are interested in this stuff, I highly recommend "The Red Queen" by Matt Ridley. http://amazon.com/Red-Queen-Evolution-Human-Nature/dp/006055...

This is a great passage from the Red Queen, that might explain what was happening at the time:

In the ancient empire of the Incas, sex was a heavily regulated industry. The sun-king Atahualpa kept fifteen hundred women in each of many “houses of virgins” throughout his kingdom. They were selected for their beauty and were rarely chosen after the age of eight—to ensure their virginity. But they did not all remain virgins for long: They were the emperor’s concubines. Beneath him, each rank of society afforded a harem of a particular legal size. Great lords had harems of more than seven hundred women. “Principal persons” were allowed fifty women; leaders of vassal nations, thirty; heads of provinces of 100,000 people, twenty; leaders of 1,000 people, fifteen; administrators of 500 people, twelve; governors of 100 people, eight; petty chiefs over 50 men, seven; chiefs of 10 men, five; chiefs of 5 men, three. That left precious few for the average male Indian whose enforced near-celibacy must have driven him to desperate acts, a fact attested to by the severity of the penalties that followed any cuckolding of his seniors. If a man violated one of Atahualpa’s women, he, his wife, his children, his relatives, his servants, his fellow villagers, and all his lamas would be put to death, the village would be destroyed, and the site strewn with stones. As a result, Atahualpa and his nobles had, shall we say, a majority holding in the paternity of the next generation. They systematically dispossessed less privileged men of their genetic share of posterity. Many of the Inca people were the children of powerful men. In the kingdom of Dahomey in West Africa, all women were at the pleasure of the king. Thousands of them were kept in the royal harem for his use, and the remainder he suffered to “marry” the more favored of his subjects. The result was that Dahomean kings were very fecund, while ordinary Dahomean men were often celibate and barren. In the city of Abomey, according to one nineteenth-century visitor, “it would be difficult to find Dahomeans who were not descended from royalty.” The connection between sex and power is a long one.

Post reply on HN