I've just discovered the Y-chromosome bottleneck

[GarlicAnything]

When reading that patriarchy's approximately 5,000 years old, I haven't found serious justifications for it. Arguments seemed mostly to be about men being buried with posher grave goods (but women have been buried with equally swanky goods after that) and a reduction in 'venus' icons (but we don't know what they were for, and goddess worship doesn't prove anything anyway).

It never occurred to me to look at DNA. Here it is, though it happened more like 7,000 years ago. Google says:

The Neolithic Y-chromosome bottleneck was a sharp drop in male genetic diversity that occurred globally between 7,000 and 5,000 years ago. 1, 2]

What Happened

• Genetic collapse: Diversity in the male Y-chromosome dropped so fast that it looked like only one man reproduced for every 17 women.
• Only men affected: Mitochondrial DNA (passed down through mothers) showed normal, steady growth. This rules out general disasters like famines, plagues, or climate change. 1, 2, ]

Why It Happened
Scientists link this event to the shift from hunter-gatherer groups to farming and agro-pastoralist cultures. Two main ideas explain the drop: 1, 2]

• Patrilineal warfare: Early research suggests that wealth and power grew in male-dominated clans. Competing clans fought wars where entire family lines of men were killed, wiping out their specific Y-chromosomes. 1, 2, 3]
• Peaceful social structures: Newer models show that strict patrilineal and patrilocal systems (where land and names stay with male kin groups) can naturally reduce Y-chromosome diversity over time through normal social fission and unequal reproductive success, without requiring massive violence. 1, 2, 3]

One man reproduced for every 17 women! No matter what narrative we superimpose on this, it's quite an unpleasant picture. 17 women getting pregnant for each impregnator. Men indisputably took control over women and dictated which men they could reproduce with.

I think the 'peaceful' patrilocal societies must've been established by force, since I can't imagine women all over the world cheerfully leaving their homes to join strangers' harems.

Y-chromosome diversity recovered in a rapid spate of 'star-shaped' explosions from 5,000 years ago, when cities and city-states became the norm. People from what had been discrete rural settlements moved to the cities and mingled, then the city-states started fighting each other and taking each other's populations as prisoners. This resulted in more men and genetic mixture, with the star shapes being patterns of Y diversity radiating out from the city centres.

Sadly, it doesn't look like the men gave up controlling women's reproductive options and living conditions, although far fewer of them had as many as 17 wombs at their disposal.

Women made a patchy comeback at times. Now archaeology's giving up its sexist assumptions and re-examining grave finds, it's becoming clear that many societies throughout history have been female-led and matrilocal. I'm happy to note that this seems especially the case in Britain - our Celts buried more 'warrior queens' than they did in mainland Europe, for instance, though of course there's still much more to be discovered.

Absolutely: many HG settings were food-abundant. Even so, there were some that were not. A good example are the Selk’nam people who lived in Tierra del Fuego: a circumpolar, subfertile region, prone to the very occasional appearance of whale-carcasses. You can imagine the havoc that such a massive source of nourishment would unleash on a population that lived close to starvation. As a result, the men enforced a very strict order of distributing whale-meat. And you can maybe guess how women stood relative to men in Selk’nam life.

Thank you for this thread.

There is also the not infrequent system where the bureaucratic administrators of some powerful empires were eunuchs. They could be individually powerful and rich and respected, but they wouldn't have descendants to scheme for.

Meanwhile the leaders had large numbers of wives / slaves, so could build up a genetic legacy, but were also possibly more exposed to the risks of warfare than their paper-pushers.

The past was different.

I often find these threads a little optimistic - we want things to have been better for women in the past.
Can you see the men allowing women to choose the best of them?
Likely the most violent and aggressive subdued the weaker men then took the women as wives/mothers.
Meaning that aggressive male traits are propagated.
It makes sense from an evolution point of view and explains a lot about modern men.
Someone pointed out orangutans are matriarchal. I don't think they are, but bonobos are. However, chimps are patriarchal with one male fertilising most of the females.

The Byzantine Empire springs to mind ....

One thing I haven't seen mentioned (sorry if I haven't read carefully enough,) is that in modern polygamous societies men can have more than one wife because their wives are much younger (30 year old man marries 20 year old woman then marries another 20 year old aged 40 and then aged 50).
There are fewer 50 year old men in the population than there are 20 year old women.
So men don't always need to rape or capture women to have lots of wives - they just need to pick very young women and wait till the other men die.
They may also have lots of wives in succession (I'm sure some early modern women at least were afraid of pregnancy due to the risk of death).

Byzantium, Babylon, China, Assyria, Ethiopia, Korea, Egypt . . . . . .

It was so usual, and so efficient in achieving its ends, that I suspect it happened anywhere that society was complex enough to have an upper class that would find strong intelligent men with no dynastic ambitions useful.

I know, it’s a nice thought, but yes, probably over-optimistic.

I mentioned orangutans, and whilst they aren’t strictly matriarchal, the females live in overlapping territories, and the males are completely solitary and join the female ‘groups’ just long enough to breed.

Still a better social structure than our human patriarchy. I recall reading about a troop of baboons than became matriarchal after all the aggressive males died, so maybe there’s hope for us yet?

What’s it gonna be called and when is it out?!

Ahhh that would be telling just now. But the writing is going very well and I expect to have a first draft by Easter. Will update you once it’s ready!

Yes - and I think the Christian convention of monastic celibacy was a version of this. The church effectively operated (in several ways - care of the sick, education, administration of lands) as a state bureaucracy.

Evo-psych defenders of patriarchy often overlook how artificial it actually is, in terms of what we know about female sexuality. For obvious reasons, women are WAY more selective than men about who they go to bed with. But the more patriarchal a set-up, the less choice they have over their partners. Fully patriarchal societies hand women over as objects. Nothing in our biological evolution agrees with this. As such, I still have (some) hope.