THREE'S COMPANY?: Scientists studying the genes of disparate populations have shown that monogamy was not the norm in generations past.
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Researchers report genetic evidence bolstering the socially contentious idea that polygyny—the mating practice where some males dominate reproduction by fathering children with several women—was the norm for sexual behavior throughout human history and prehistory. Because polygyny means other men father few or no children, the study, published today in PLoS Genetics, also shows that, on average, women bequeath more genes to their offspring than men do.
The proportion of female to male genes passed on is not yet known. "Our follow-up work is to get a better estimate, but we believe it's at least two to one, if not more," says senior study author Michael Hammer, a geneticist at the University of Arizona in Tucson.
"This is good science, and even more notable is the increasing light it sheds on our own human nature," says David Barash, evolutionary psychologist, University of Washington in Seattle.
The study, which examined genetic material (DNA) from six geographically diverse populations—Biaka from Central African Republic, Mandenka from Senegal, San from Namibia, French Basque, Han Chinese and Melanesians from Papua New Guinea—provides independent corroboration of what many animal studies have shown and evolutionary biologists have long claimed: basic human biology is polygynous, Barash notes. "Monogamy is a recently inspired cultural add-on."
Researchers examined DNA areas devoid of genes in each of 90 people, including 20 regions on the X chromosomes (present in both male and female mammals) and 20 on the autosomes (the other 22 chromosomes, which are not involved in sex determination). If an equal number of males and females breed successfully, genetic variation in the two kinds of chromosomes should be about equal. Instead, the researchers found much more variation on the X than on autosomes.
The paper explored explanations for this X genetic diversity, concluding that polygyny was the most likely.
The notion that monogamy is not "natural" for humans has been controversial because some fear it may provide a biological justification for promiscuity. "But it's a fallacious idea that we can infer from what is the case something about how we ought to act," says Erik Parens, senior research scholar at The Hastings Center bioethics think tank based in Garrison, N.Y. "I don't see why we should accept the premise that we can read off of how our forebears acted…[the way]…we ought to act now."
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17 Comments
Add CommentDr. Michael Hammer is an absolutely brilliant geneticist. He included my family in genetic comparisons in 1999. Interestingly, some of the groups identified in his current study, who are among humans' second most ancient ancestors, the Biaka Pygmies from the Central African Republic and their most ancient ancestors, the San of Namibia, -- showed in comparisons of my father's Y chromosome DNA.
Reply | Report Abuse | Link to thisAs it is, my dad, a minister, has lived a long, monagamous life. So has my younger brother. My elder brother, on the othe hand, well, no comment. Genealogical records show that one of my granddads and ancestors in medieval Ghana bore children simultaneously with multiple ladies. My other granddad was monogamous. So too on my maternal side, one uncle was monagamous, the other was not. And among my ancestors in the late 1700s, I found records of one brother who was monogamous and the other who was not.
So in spite of the DNA inherited, socialization, personality and the moral environment of one's generation play alongside DNA. I look forward to more experiments on DNA, culture, personality and personal choice, or what we call, human will.
this research is really amazing...
Reply | Report Abuse | Link to thisCan you please tell us which is your opinion about what Jesus have said in Matthews Gospel 5:27-28 but also in the verses 1-11 in chapter 7 from the First Epistle of Paul the Apostle to the Corinthians? Is it possible for God who created man and woman and the whole universe, to put wrong rules and give wrong advices to them whom are -as you say through researchers examined DNA - impossible to follow?
Reply | Report Abuse | Link to thisCan you also inform us if the researches have carried out only by men or both men and women?
Matthew 5:27-28 - "You have heard that it was said to the people in the old days, 'You shall not commit adultery'. But I say to you that every man who looks at a woman lustfully has already committed adultery with her - in his heart.
1 Corinthians 7:1-2 - Now let me deal with the questions raised in your letter. It is a good principle for a man to have no physical contact with women. Nevertheless, because casual liaisons are so prevalent, let every man have his own wife and every woman her own husband.
7:3-5 - The husband should give his wife what is due to her as his wife, and the wife should be as fair to her husband. The wife has no longer full rights over her own person, but shares them with her husband. In the same way the husband shares his personal rights with his wife. Do not cheat each other of normal sexual intercourse, unless of course you both decide to abstain temporarily to make special opportunity for fasting and prayer. But afterwards you should resume relations as before, or you will expose yourselves to the obvious temptation of the devil.
7:6-9 - I give the advice above more as a concession than as a command. I wish that all men were like my self, but I realise that everyone has his own particular gift from God, some one thing and some another. Yet to those who are unmarried or widowed, I say definitely that it is a good thing to remain unattached, as I am. But if they find they have not the gift of self-control in such matters, by all means let them get married. I think it is far better for them to be married than to be tortured by unsatisfied desire.
7:10-11 - To those who are already married my command, or rather, the Lord's command, is that the wife should not leave her husband. But if she is separated from him she should either remain unattached or else be reconciled to her husband. A husband is not, in similar circumstances, to divorce his wife.
Danae Kotsis, Athens Greece
dakotsis@yahoo.gr
Danae,
Reply | Report Abuse | Link to thisthis discussion seems futile to me, but let me still answer you:
1. Your statement that god has "created man and woman and the whole universe" is probably citing the beginning of the Old Testament, which is a collection of stories and myths of ancient Jewish people. Most readers of this article do not belong to the Jewish people (whom I fully respect) and the article is not dealing with mythology, so where is the relevance?
2. You are quoting Matthew: "But I say to you that every man who looks at a woman lustfully has already committed adultery with her - in his heart." This statement is of course true and is not in contradiction with Dr. Hammer's research. So where is the problem?
3. I am sure that there has been one steady element through all times of human history and prehistory and this is diversity. In old times, just as today, there were human cultures living in polygyny and others living in monogamy. Our species has been existing for more than a million years - this is 50,000 generations of men and women - and with our great cultural flexibility and ability to adapt, probably all variations of human societies must have existed for some times and at various places. Even the Bible is full of stories of people who tried things out like incest, sex with slaves, coitus interruptus and many things more.
4. Polygamy is perfect in societies with lots of violence between males, including war and crimes. The Islam proposes that wealthy men should marry women who lost her husbands or are at risk to stay alone, in order to prevent them and their children from poverty and starvation. Probably a good advice at that time.
5. Monogamy is a better adaptation when there is high risk of generic and other diseases.
Evolution does not only happen for species but also for cultures, didnt you know?
It is also a fact that women frequently died in childbirth. Anyone who has looked at geneology will note that many men had serial marriages, thereby fathering a number of children with different wives without ever commiting adultery. Of necessity, that must have left a good number of men without mates.
Reply | Report Abuse | Link to thisIt is also to be mentioned that women frequently died at an early age, particularly during childbirth, that therefore men frequently married serially, therefore having a number of children with several wives while never committing adultery. Needless to say, that must have left a number of other men without mates or progeny.
Reply | Report Abuse | Link to thisGood point!
Reply | Report Abuse | Link to thisDear Extremophile,
Reply | Report Abuse | Link to thisFirst, I want to thank you for your attitude to deal with my concerns.
But I want you to tell me your opinion on the first letter to Corinthians which I have also mentioned.
I would also like to say that by reading the Bible we understand that in the Old Testament were applying different rules and God wanted a different attitude from people from this that asks after the Crucifixion and Resurrection of Jesus in the New Testament. In the Old Testament the law which God sent through Moses had the power and people had to carry it out to save themselves. In the New Testament, people can be saved only through believing in Christ, namely His sacrifice.
So I would like to reach the conclusion that eventually over the years and because the needs of humans have modified, perhaps they change their behaviour and wishes in order to survive.
Danae: You have pointed out many passages that explain how spouses are to treat each other, but I have not yet seen a single reference to marriage being limited to a single man and a single woman. Even if I have several wives like Abraham, Moses, Job and countless others in the bible (http://www.biblicalpolygamy.com/polygamists/) and I look lustfully at another man's wife or wives, then I have committed adultery. Still says nothing about only having one wife. Besides, that Adultery thing is purely Old Testament.
Reply | Report Abuse | Link to thisConsistency folks. Use it.
What's all the fuss about a genetic predisposition to polygny? While not "hard wired", we are "soft wired" -- we inherit predispositions, and it is our culture that reinforces some predispositions and counteracts others. Humans inherit a predisposition for polygny, and the lines of evidence for this are increasing. To wit:
Reply | Report Abuse | Link to thisa.. primate along with many other species are polygnous; b.. males continuously replenish their gametes while females have a fixed supply, thus one male can impregnate far more females than one female can be impregnated; c.. a male can impregnate one or more females per day whereas an impregnated female is "out of service" for nine months, and is impregnatable after that for only a few days per month. d.. Hammer's paper simply adds human genotypic confirmation to the above phenotypic evidence. Our genes provide copious physical evidence for some ancient scenarios, and against others. While the evidence is indirect, and we can never know for sure, we accept indirect evidence for plenty of other things we will never see, such as quarks, black holes, the Big Bang, etc.
Polygny is the result of natural selection, so must enhance survival, recent cultural resistance notwithstanding. Indeed cultural norms, both ancient and current, reinforce polygny through the approved practices of polygamy, harems, concubines
Comment continuation: To wit:
Reply | Report Abuse | Link to this• primate along with many other species are polygnous;
• males continuously replenish their gametes while females have a fixed supply, thus one male can impregnate far more females than one female can be impregnated;
• a male can impregnate one or more females per day whereas an impregnated female is "out of service" for nine months, and is impregnatable after that for only a few days per month.
• Hammer's paper simply adds human genotypic confirmation to the above phenotypic evidence.
Our genes provide copious physical evidence for some ancient scenarios, and against others. While the evidence is indirect, and we can never know for sure, we accept indirect evidence for plenty of other things we will never see, such as quarks, black holes, the Big Bang, etc.
Polygny is the result of natural selection, so must enhance survival, recent cultural resistance notwithstanding. Indeed cultural norms, both ancient and current, reinforce polygny through the approved practices of polygamy, harems, concubines, ...
Commet continued: To wit: primate along with many other species are polygnous; males continuously replenish their gametes while females have a fixed supply, thus one male can impregnate far more females than one female can be impregnated; a male can impregnate one or more females per day whereas an impregnated female is "out of service" for nine months, and is impregnatable after that for only a few days per month.
Reply | Report Abuse | Link to thisHammer's paper simply adds human genotypic confirmation to the above phenotypic evidence.
Our genes provide copious physical evidence for some ancient scenarios, and against others. While the evidence is indirect, and we can never know for sure, we accept indirect evidence for plenty of other things we will never see, such as quarks, black holes, the Big Bang, etc.
Polygny is the result of natural selection, so must enhance survival, recent cultural resistance notwithstanding. Indeed cultural norms, both ancient and current, reinforce polygny through the approved practices of polygamy, harems, concubines, ...
Danae, the short answer is that all your questions relate to MORAL/ETHICAL choices (ie about what it is right for people to do) but what Ms Powledge was writing about was a FACTUAL/HISTORICAL issue of what large numbers of people have actually done (even if it turns out that they were wrong to do it). She makes no comment whatever that might contradict the teaching of Jesus or any other religious teacher. Think about it this way: What anyone might feel they want to do is a matter that science can study and report on; whether or not they should refrain from doing it is a matter of what is right and wrong, about which science can say nothing.
Reply | Report Abuse | Link to thiswife not wives
Reply | Report Abuse | Link to thisEphesians 5:33
However, each one of you also must love his wife as he loves himself, and the wife must respect her husband.
Ephesians 5:32-33 (in Context) Ephesians 5 (Whole Chapter)
Is it not clear that one wife was the example to be set forth?
1 Timothy 3:2
Now the overseer must be above reproach, the husband of but one wife, temperate, self-controlled, respectable, hospitable, able to teach,
1 Timothy 3:1-3 (in Context) 1 Timothy 3 (Whole Chapter)
1 Timothy 3:12
A deacon must be the husband of but one wife and must manage his children and his household well.
1 Timothy 3:11-13 (in Context) 1 Timothy 3 (Whole Chapter)
Titus 1:6
An elder must be blameless, the husband of but one wife, a man whose children believe and are not open to the charge of being wild and disobedient.
Titus 1:5-7 (in Context) Titus 1 (Whole Chapter)
wife not wives
Reply | Report Abuse | Link to thisEphesians 5:33
However, each one of you also must love his wife as he loves himself, and the wife must respect her husband.
Ephesians 5:32-33 (in Context) Ephesians 5 (Whole Chapter)
Is it not clear that the example set forth is one of monogomous relationships?
1 Timothy 3:2
Now the overseer must be above reproach, the husband of but one wife, temperate, self-controlled, respectable, hospitable, able to teach,
1 Timothy 3:1-3 (in Context) 1 Timothy 3 (Whole Chapter)
1 Timothy 3:12
A deacon must be the husband of but one wife and must manage his children and his household well.
1 Timothy 3:11-13 (in Context) 1 Timothy 3 (Whole Chapter)
Titus 1:6
An elder must be blameless, the husband of but one wife, a man whose children believe and are not open to the charge of being wild and disobedient.
Titus 1:5-7 (in Context) Titus 1 (Whole Chapter)
It hardly seems like news that humans have been somewhat polygynous throughout history and prehistory--and it seems equally clear that humans have never been as polygynous as some of our close relatives, such as orangutans and gorillas. Nor have we been as monogamous as other close relatives such as siamangs and gibbons. But it seems silly to suggest that because polygyny is evident in our genes, polygyny in humans is desirable either from a moral or an evolutionary standpoint. Simply because something is "natural" does not mean that the thing is "good." I will leave it to others to worry about whether polygyny is a moral good or evil. But does the genetic evidence mean that polygyny is superior to monogamy as a human evolutionary strategy? I doubt it. Rates of polygyny are by far the highest in Central and Western Africa and in the Carribean. So, for some populations, a high rate of polygyny has arguably proved to be suitable and adaptive to this point--but it is difficult to say that the more monogamous populations living outside Africa and the Carribean are pursuing a maladaptive strategy. Indeed, the underlying premise of the study reported above is that monogamy leads to higher levels of autosomal variety, and that variety would seem to me to be an evolutionary advantage. So the fact that humans have always been polygynous to some degree hardly makes a "case against monogamy."
Reply | Report Abuse | Link to thisThere is no way that women contribute more genes to their children than men do. A mother may contribute more genes to her particular children than does a particular man. Still, there are men that contribute more genes to children than does a particular woman.
Reply | Report Abuse | Link to thisBelieve it or not. If 100 children are born, 1/2 of all their genes came from men and 1/2 came from women.