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rock hunter
03-21-2015, 06:59 AM
An analysis of modern DNA uncovers a rough dating scene after the advent of agriculture.
FRANCIE DIEP MAR 17, 2015


Once upon a time, 4,000 to 8,000 years after humanity invented agriculture, something very strange
happened to human reproduction. Across the globe, for every 17 women who were reproducing, passing
on genes that are still around today—only one man did the same.

"It wasn't like there was a mass death of males. They were there, so what were they doing?" asks Melissa Wilson Sayres, a
computational biologist at Arizona State University, and a member of a group of scientists who uncovered this
moment in prehistory by analyzing modern genes.

Another member of the research team, a biological anthropologist, hypothesizes that somehow, only a few men
accumulated lots of wealth and power, leaving nothing for others. These men could then pass their wealth on to their
sons, perpetuating this pattern of elitist reproductive success. Then, as more thousands of years passed, the numbers
of men reproducing, compared to women, rose again. "Maybe more and more people started being successful," Wilson
Sayres says. In more recent history, as a global average, about four or five women reproduced for every one man.

http://www.psmag.com/nature-and-technology/17-to-1-reproductive-success

glentane
03-21-2015, 02:09 PM
Until recently, many women eventually died in childbirth, or of complications/infections associated with pregnancy both before and after. Motherless children have a hard time, as the song says. It was a matter of urgency for a widowed father to acquire a new wife by any means necessary. Result? Another sackful of brats, and very likely another tragic demise. Rinse and repeat?

Rick
03-21-2015, 02:28 PM
Polygyny. Seems obvious enough.

J Man
03-22-2015, 01:12 AM
Polygyny and patriarchy.

Megalophias
03-22-2015, 03:11 AM
It's fine to say "polygyny", but how exactly do you convince 17 women to be nice faithful co-wives and not run off with some other guy? How do you stop the other 16 guys from ganging up on you and taking your women? If you were living in a society where you and a bunch of other guys were permanently womanless while some rich old guy had all the girls, would you just shrug your shoulders and say "well polygyny is the thing this millennium, I guess"?

There has to be some sort of pretty potent social mechanism in play to make that degree of polygyny viable.

Rick
03-22-2015, 01:24 PM
I don't know exactly how to convince them. I'm very happy with my one. We should rather ask how King Solomon, or the Sultan of Brunei, or Joseph Smith, or Brigham Young, or Bill Clinton, or Hugh Hefner or any of numerous historical and modern men how they did it. I think you're correct in your identification of some of the societal tensions such a system might produce. Large numbers of wifeless men might make trouble. But that needn't have been internally focused against one's own chief or King (or, ahem,father). It could just as well be focused externally, on conquest. Such a scenario could account for the starburst pattern we find in many y-dna lineages. I argued this on the old forum in the context of the relative older age of genetic eve than genetic adam. This 17:1 argument is much the same. By no means proved, but consistent with the genetic evidence.

RCO
03-22-2015, 01:33 PM
Some social structures associated with some types of Y-DNA could grow and expand into several new branches while other types died or remained with old styles of life at minimal subsistence levels. New frontiers of expansions, new technologies, new types of agriculture, pastoralism, metals and new forms of social and political structures can explain what happened.

lgmayka
03-22-2015, 03:22 PM
There has to be some sort of pretty potent social mechanism in play to make that degree of polygyny viable.
To summarize what others have already said, there are two rather obvious answers:
- War, which traditionally kills men but rapes women
- Power and the competition for power, which traditionally impels men to accumulate wives, concubines, paramours etc. at the expense of other men.

According to one source (http://muse.jhu.edu/journals/jmw/summary/v006/6.1.salhi.html), polygyny is on the rise in Saudi Arabia and perhaps elsewhere:
---
...a revival of polygyny that began in Saudi Arabia in the late 1970s is now spreading to the rest of the Muslim world. It is believed that this return to the old practice of polygyny is being experienced as part of the Islamic revival spreading across the region.

Polygamy and Law in Contemporary Saudi Arabia demonstrates that polygyny is widely practiced in the country and its popularity is constantly increasing among both the educated and the non-educated. Yamani demonstrates that among the reasons that contributed to its spread is the increase in wealth on the one hand and a return toward Islamic religious values on the other.

...the Prophet limited the practice to no more than four wives, despite the fact that he himself concurrently married nine wives for political reasons which did not apply to other Muslims. This matter is documented in chapter 4 of the Qur'an (Sura al-Nisa') which deals with women's rights and duties in the Islamic context.
...
The author qualifies the modern controversy over polygyny, which began in the nineteenth century, as being a result of Western influence. While Muslim countries rallied against the practice and advocated reform for women, Saudi Arabia remained the exception, and the debate around polygyny which led to its abolition in some countries and its restriction in others did not reach Saudi Arabia.
---

Webb
03-22-2015, 11:48 PM
It's fine to say "polygyny", but how exactly do you convince 17 women to be nice faithful co-wives and not run off with some other guy? How do you stop the other 16 guys from ganging up on you and taking your women? If you were living in a society where you and a bunch of other guys were permanently womanless while some rich old guy had all the girls, would you just shrug your shoulders and say "well polygyny is the thing this millennium, I guess"?

There has to be some sort of pretty potent social mechanism in play to make that degree of polygyny viable.

The Chinese just castrated any males working in the palaces. This kept the royal wives "safe" from pregnancies other than sired by the emperor.

glentane
03-23-2015, 12:57 AM
Errm .. I refer the Honourable Members to my previous assertion, and humbly beg them to recognise that, prior to the advent of Galen, Harvey, and all those nutty English chemists, being a fertile woman was a pretty dodgy proposition.
I'm holding out for sequential polygamy. In the West, at least.

Megalophias
03-23-2015, 05:38 AM
Errm .. I refer the Honourable Members to my previous assertion, and humbly beg them to recognise that, prior to the advent of Galen, Harvey, and all those nutty English chemists, being a fertile woman was a pretty dodgy proposition.
I'm holding out for sequential polygamy. In the West, at least.

17 in a row though... I suppose you'd just leave the wedding decorations up to save time.

geebee
03-23-2015, 01:42 PM
You know, men and women have different recombination rates. It's generally higher for women, which means that for any given child, you expect the DNA inherited from the mother to be in the form of a somewhat larger number of distinct "pieces", even though the total number of chromosomes and the total amount of DNA from each parent will be the same.

The question is, would one effect of this over time be to make it *appear* that DNA has more female "sources" than male? In other words, is it possible that the 17 to 1 difference is not because that's what actually happened 8000 years ago, but that's how it looks in terms of the inherited DNA?

(Maybe someone more mathematically inclined and familiar with the recombination rate differential will take a closer look at this.)

EDIT: Okay, taking a closer look at the study, I see that didn't look at the autosomes at all. I'm not sure you can infer from male-male lines how many men of a given period actually reproduced. You can only know how many had sons, and sons' sons, etc., down to the present day.

There may be other reasons for greater diversity in mtDNA than simply that more women were reproducing in the first place. We're only looking at a tiny fraction of all lines from 8000 years ago, though uninterrupted by any females.

Arbogan
03-24-2015, 09:51 PM
Assuming more women survived than men. I don't see how it's impossible. But not at the ratio of 1:17.

Raskolnikov
03-27-2015, 12:54 PM
So if around 80-90% of women reproduced that means 4.7-5.3% of men reproduced. I don't understand this at all, even if those 5% were elites the other men could easily take over, how could such a society survive? Though, I suppose that's why they didn't. In ancient times how could 5% of men stop 95% of men from reproducing without the connivance of women? This is an extremely significant finding and needs to be looked at in great detail. One can easily see the advantages of a relatively more monogamous society, such a society in which most men had a real stake could easily outcompete an ultra-polygynous one.

BMG
03-27-2015, 04:50 PM
It need not be so drastic from the start itself . If 98 males reproduced for 100 females for each generation then after 100 generations the no of female ancestors would be almost 10 times than the no of male ancestors .

newtoboard
03-29-2015, 01:34 PM
This seems pretty obvious. 2 subclades of y R. Almost 100 for mt H. I wonder if we will find extinct lineages in aDNA. So far nothing besides the Malta R*/R3.

On a related note does anybody think Toba eliminated some of the more upstream lineages in Eurasia such as A, B, CT, CF, and DE?

nuadha
03-29-2015, 10:23 PM
You know, men and women have different recombination rates. It's generally higher for women, which means that for any given child, you expect the DNA inherited from the mother to be in the form of a somewhat larger number of distinct "pieces", even though the total number of chromosomes and the total amount of DNA from each parent will be the same.

The question is, would one effect of this over time be to make it *appear* that DNA has more female "sources" than male? In other words, is it possible that the 17 to 1 difference is not because that's what actually happened 8000 years ago, but that's how it looks in terms of the inherited DNA?

(Maybe someone more mathematically inclined and familiar with the recombination rate differential will take a closer look at this.)

EDIT: Okay, taking a closer look at the study, I see that didn't look at the autosomes at all. I'm not sure you can infer from male-male lines how many men of a given period actually reproduced. You can only know how many had sons, and sons' sons, etc., down to the present day.

There may be other reasons for greater diversity in mtDNA than simply that more women were reproducing in the first place. We're only looking at a tiny fraction of all lines from 8000 years ago, though uninterrupted by any females.

Spot on analysis.

Megalophias
03-29-2015, 10:54 PM
This seems pretty obvious. 2 subclades of y R. Almost 100 for mt H. I wonder if we will find extinct lineages in aDNA. So far nothing besides the Malta R*/R3.

Ust'-Ishim man also had an extinct clade of K2a*. Actually I think a lot of them are extinct if you go down to the terminal clade.

I don't think you can directly compare the number of branches from a given level between Y DNA and mtDNA. Y DNA has millions of base pairs, mtDNA only 16 600, so Y DNA has a far higher phylogenetic resolution. You can distinguish splits only a few generations apart with Y DNA. I'm no expert on this and I could be wrong, but I'd guess that P1, P2, M, S, NO, K*, L, and T would all be primary branches of K with no substructure if it were mtDNA. Possibly primary branches of F, even.

Ebizur
03-31-2015, 01:41 PM
Ust'-Ishim man also had an extinct clade of K2a*. Actually I think a lot of them are extinct if you go down to the terminal clade.

I don't think you can directly compare the number of branches from a given level between Y DNA and mtDNA. Y DNA has millions of base pairs, mtDNA only 16 600, so Y DNA has a far higher phylogenetic resolution. You can distinguish splits only a few generations apart with Y DNA. I'm no expert on this and I could be wrong, but I'd guess that P1, P2, M, S, NO, K*, L, and T would all be primary branches of K with no substructure if it were mtDNA. Possibly primary branches of F, even.It's all relative, but I would say that at least the ancestors of Q and R (descendants of P1-M45) probably have shared a significant amount of time (approximately 13,000 to 14,000 years according to Hallast et al. 2014) as members of a particular tribe somewhere (perhaps in some part of Siberia), and this shared history distinct from other populations is ultimately responsible for the "ANE effect" that has been observed in analyses of the autosomal variation of present-day human populations.

The exclusively shared history of N-M231 and O-M175 seems to have been less significant (perhaps only about 4,000 to 6,500 years). I expect that it should be relatively difficult to discern a distinctive "NO-M214 tribe effect" in modern autosomal DNA.

The IJ-M429 linkage may be slightly weaker than even the NO-M214 linkage, and the linkages between H and IJK vs. G, L and T vs. MNOPS, etc. are practically insignificant.

4217

Neo
09-30-2015, 12:22 PM
It's fine to say "polygyny", but how exactly do you convince 17 women to be nice faithful co-wives and not run off with some other guy? How do you stop the other 16 guys from ganging up on you and taking your women? If you were living in a society where you and a bunch of other guys were permanently womanless while some rich old guy had all the girls, would you just shrug your shoulders and say "well polygyny is the thing this millennium, I guess"?

There has to be some sort of pretty potent social mechanism in play to make that degree of polygyny viable.



I think the case the wealthy stayed healthy even even back during Neolithic times held true.More begat more.If a polygamous man was a good hunter, he could provide for more than 2 wives and those wives could produce through harvest and crop gathering. Many men could of also acquired wealth by hunting and have their wives harvest for them.So more wives would yield more grain and crops.Thefore in a reproductive war of attrition ,men with more than one wife had more food resources and could feed more mouths, there by increasing these polygamous husbands ability to sustain more offspring. Later on these offspring could either do hunting or harvesting themselves.I would also imagine that men probably reproduced even into old age during the Neolithic times,and those that lived longer probably had more time to produce more offspring while they lived.



Ust'-Ishim man also had an extinct clade of K2a*. Actually I think a lot of them are extinct if you go down to the terminal clade.

I don't think you can directly compare the number of branches from a given level between Y DNA and mtDNA. Y DNA has millions of base pairs, mtDNA only 16 600, so Y DNA has a far higher phylogenetic resolution. You can distinguish splits only a few generations apart with Y DNA. I'm no expert on this and I could be wrong, but I'd guess that P1, P2, M, S, NO, K*, L, and T would all be primary branches of K with no substructure if it were mtDNA. Possibly primary branches of F, even.

In general aren't there more mt-DNA clades and subclades the Y-DNA? More mtDNA survives despite the less variety of base pairs for Y-DNA.Also Mt-DNA dates back earlier than Y-DNA.