September 27, 2008
The X Chromosome and the Case against Monogamy
From Scientific American:
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."
More here.
Posted by Azra Raza at 06:30 AM | Permalink
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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."
Well said. An is ain't an ought and all that jazz. Still, I wonder how many men will use this as an excuse, "But honey, I'm made this way! The nerds totally said so!"
Posted by: spgreenlaw | Sep 27, 2008 9:26:53 AM
"...basic human biology is polygynous, Barash notes."
This is an overreach. Polygynous behavior is hypothesized by the authors of this study as one explanation (among several alternatives which are not described in detail) for the genetic traits they found. This research seems to reinforce the pre-existing theories of some scientists, who naturally will hold it up as "good science" for that reason.
But polygyny is but one of several behavior patterns that might arise in humans (or other animals) as a response to various environmental or cultural factors. Dawkins' discussion in "The Selfish Gene" is on point here: even if genetic and environmental variance is limited, multiple stable behavioral patterns may emerge.
The phenomenon reported in this research does not even mean that polygyny was "predominant" in any historical period: even if most couples were monogamous, a relatively small number of polygynous men fathering larger numbers of children could account for the disparities they found.
Posted by: Nizam Arain | Sep 27, 2008 12:29:35 PM
"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."
Will someone explain this to me. Why does the fact, if it is a fact, that a greater percentage of women than men have children mean that "women bequeath more genes to their offspring than men do." If a man has an offspring, he provides half the genes doesn't he? For each "offspring" aren't the percentage inherited from the father and mother identical.
Posted by: David Hammer | Sep 27, 2008 1:04:45 PM
Dave, it's because the next generation of children (as a group) will have (say) 10 fathers, and 50 mothers. It's not talking about individuals' genetic makeup.
Posted by: - | Sep 27, 2008 5:19:13 PM
It is indeed a common misconception (particularly among males) that polygamy would be beneficial and in some way "right" based on our evolutionary roots. What is often forgotten, however, is that if our society was entirely based upon the concept of polygamous relationships, evolutionary instincts would come a lot higher in choosing a partner. Why would women settle for anything less than the tallest, strongest men that will clearly give the best genes? In a way polygamy is "right", but not as the modern male sees it; the idea of not having to choose one partner is a way of creating the strongest and most pure gene pool possible. The downside of course is that if your genes are not cuts above the rest (perhaps you're short and susceptible to obesity), then women have no reason to be attracted to you and as such your genes will not be passed on. The obvious benefit of this for us as a race is that we would have a very strong gene pool, meaning we would on average have better health and a longer life expectancy.
So in a modern sense, it is greatly in the interest of most males that we are a monogamous society. Our genes don't care about a good personality or a sense of humour, they care about survival.
Posted by: Nate | Oct 23, 2008 10:05:07 PM
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