Slashdot Mirror
Monogamy May Have Evolved To Prevent Infanticide
sciencehabit writes "Human males and females have a strong tendency to live together in monogamous pairs, albeit for highly varied periods of time and degrees of fidelity. Just how such behavior arose has been the topic of much debate among researchers. A new study comes to a startling conclusion: Among primates, including perhaps humans, monogamy evolved because it protected infants from being killed by rival males."
and killing offspring is directly opposed to the core of evolutionary theory
Unless those offspring are in direct competition for food and reproductive access with your offspring. Then it makes a lot of sense evolution-wise.
Been there, done that.
No, science is not religion, in the way you're implying it is. Science works by creating theories (either from educated guesses or observations, often both) and testing them.
If it can't be tested, it's not science*.
*Of course, one thing is not being capable of measuring something - the fact that light is affected by gravity took a while to test, for instance. That doesn't make it impossible to test.
Clearly you didn't read the article. The very study linked in the summary specifically compared 230 primate species, some of which are socially monogamous and some of which are not. And it explains why it *hasn't* evolved among all of the fairly similar species in the study using a model based on the infanticide rate.
There are almost certainly things to be picked apart in the study, but you need to understand the basic premise before you can start on that track.
and killing offspring is directly opposed to the core of evolutionary theory, which rewards the widest possible range of mates to guarantee diverse genetic combinations and the maximum chances for survival and spread of strong genes.
This may come as a complete surprise to you, but there do exist plenty of creatures out there that do kill the offspring and still haven't become extinct and there do exist plenty of creatures out there that do not kill their offspring and only mate with one or very few partners and still haven't managed to become extinct. Hell, there exists atleast one specific one that doesn't mate at all and produces only perfect clones of themselves, and still haven't become extinct. The point is, you cannot just lump different survival-strategies together like that and deny the existence or even the possibility for anything other than your one chosen one; what works for one type of a creature may not work for another, and the nature has the tendency of throwing all sorts of types of stuff on the wall and seeing what sticks.
Because there's no "design" to evolution. Whatever works, works. And there's not one "right" way to evolve. There's no reason for a feature that evolves in one species to independently evolve in other species (although it's possible.)
assert(birth_date<time-86400)
Just because someone else has a different hypothesis doesn't mean this one is wrong.
"First they came for the slanderers and i said nothing."
primates tend to be in bands
Except for the ones that aren't, like orangutans, a close relative of ours.
Mogamy happen because it takes a long time to rise the offspring, and it needs the support of both the female and male
That's one pressure. TFS mentions another. There can be more than one reason, and there usually are.
Tic-Tac-Toe, Global Thermonuclear War, and relationships all have the same winning move.
Can you explain why you *didn't* get into a car accident in the last month? What was it that you did that nobody else who got into a car accident last month did, to cause you to avoid all the accidents that could have happened?
You could say that Bill was drunk, or Alice was texting, and that's why they got into car accidents, but that doesn't explain how every single person that drove drunk or texted while driving didn't get into an accident.
What kind of explanation were you expecting?
Birds clearly have an advantage by being able to fly. If I said "Flying is not advantageous, because if it was, all organisms would have evolved to be able to fly", would that be convincing to you?
Here is a quote from Euripedes a writer from Ancient Greece where they had polygamy:
A second wife is hateful to the children of the first; A viper is not more hateful.
Monogamy evolved because it makes great furniture.
The study (and the linked article) go far beyond "lots of stuff could have worked and this is the one that must have come up." What is says is that monogamy hasn't evolved in other species because they don't practice infanticide. And why is that? Because big-brained animals take a long time to develop, so the young are defenseless.
I believe evolution happens, both historically and currently, and on scales both grand and small.
But I'm tired of so-called scientists making news stories out of un-testable speculations about how something or another could have been a factor in our evolutionary past.
That kind of speculation is for late-night living-room talk, not scientific journals.
How does monogamy change who is in competition with whom? There is no evolutionary mechanism to enforce monogamy. From a purely genetic standpoint there is no benefit to monogamy for a strong male.
Articles like this are just freeze dried beef pasta boiled up in 100 gallon vats and thrown to the neckbeards who gobble it up while slathering vaseline and yanking each other off.
Shit isn't even pretending to be science any more. It's just some asshole in a lab coat leading a revivial in a Kentucky tent.
The argument is that your statement about a strong male being better off without monogamy seems right but isn't, because if strong males fail to stick around and ensure the children they conceived survive to reach adulthood and carry on the cycle, it won't happen, and their "strong" genes will be wiped from the face of the earth.
-1 Uncomfortable Truth
No, it did not say that other species practiced infanticide. It said that infanticide was much more detrimental to us (and what had evolved into us) due to the extended period of helplessness during infancy. Infanticide was much too expensive for us than it is for lions and such.
Boobies never hurt anyone. - Sherry Glaser.
why it hasn't evolved in lots of other species.
IANAA (I am not an Anthropologist) but I'm going to take a stab in the dark and hypothesise that it is because human offspring require a much bigger commitment of time, energy and resources before they can fend for themselves, than the offspring of pretty much any other species on the planet. Mind you monogamy is not exactly some sort of genetic trait we have evolved. Here in the west it is largely a cultural phenomenon that the christian church has popularised. There are plenty of cultures around the world where even fairly low status males can have more than one wife and there are also cultures where wives can have multiple husbands. So it is probably more accurate to say that humans evolved to be highly social and to engage in highly structured very long term bonding to form monogamous or polygamous families, partly to minimise infanticide and to maximise the odds of their very time and resource expensive offspring reaching adulthood.
Only to idiots, are orders laws.
-- Henning von Tresckow
But the point is, it's not productive to discuss what "could be" explained by evolution, since that is practically everything and anything. You have to stick with the fossil record, DNA, and (where possible) direct experiments.
Humans, on the other hand, can have babies about once a year.
Women who nurse exclusively on average do not get their periods for 14-15 months after childbirth. Some get it right away, some go 2-3 years, but 13-16 months is the average, if they are nursing.
What is says is that monogamy hasn't evolved in other species because they don't practice infanticide.
What I was thinking when I posted was of all the nature documentaries where a male adopts a new female into his "harem" and promptly kills her young. A few weeks ago I saw a somewhat unnerving film of a zebra doing that, picking up the foal by the neck with his teeth, and bashing him down onto the ground. I believe lots of other species do it too, and I've seen films of several.
Sheesh, evil *and* a jerk. -- Jade
" From a purely genetic standpoint there is no benefit to monogamy for a strong male."
From a genetic standpoint Monogomy is a disadvantage for a strong male. A strong male should be humping everything in sight to spread his genetics far and wide.
That is how it works in nature. A male lion has a pride of females for this exact reason.
Do not look at laser with remaining good eye.
Young women are attracted to young men who take unnecessary risks in extreme displays of their adult skills. Today it's smoking the wheels of cars, not so long ago it was jumping out of trees onto wild buffalo. Every hero in every action movie does the same thing, no matter what is thrown at the hero he gets up and keeps going, no matter what the hero blows up or how many bullets he shoots no innocent bystander is ever hurt.
Young women are not attracted to 'idiots' that crash and burn, they are attracted to 'heros' who's skills and strength keep them alive and healthy despite the odds. It's not a conscious thing in either sex, "cheating death" is an integral part of the human ritual of finding a suitable mate, it's so deeply ingrained in humans that a males brain chemistry will reward "cheating death" with feelings of elation, pride, and self-satisfaction.
Looking back as an old man who had the luck to survive the motorbike ritual (among others), young men really do behave like peacocks, the things they unconsciously do to attract a mate are even more dangerous to the individual than that ridiculous tail is to the peacock. At the end of the day it does make our societies (if not our species) better suited to the civilizations we invented. We are continually evolving and are in a feedback loop with the environment we have created for ourselves, not unlike the termite and it's air-conditioned fungus farm.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Perhaps not. Maybe the mods objected to the misogyny.
It's used as a warning to others, so far Canada hasn't tried to invade us. That means it's working!
Been there. Did that.
Surrender of Detroit
Yaz>
I'd like to hypothesize that a lot of people are hung up on finding an evolutionary answer for everything. Sometimes things just happen in a species without there being an evolutionary advantage. Species are not hyper optimized. Sometimes things are just side effects. Sometimes I get a feeling that people like to anthropomorphize evolution, replacing a deity that designs with specific reasons and goals with a system that does the same thing. Especially with very fuzzy things like behavior.
Ie, I've heard people discussing the reason for grandmothers. This is a silly concept, unless your view of evolution is that it is a system that optimizes organisms. Maybe grandmothers exist because humans live longer than they used to, no need for a hand waving explanation. Others want to have an evolutionary "reason" for homosexuality. Yes, it's not a nice thought to think that it's a biological mistake, but it's certainly easy enough to think that it is because some genes are expressed at a certain time that caused various hormones to be produced at a particular time in development, and as a side effect of this slight variance in timing you end up with an organism that does not fit the standardized phenotype. May as well ask what the evolutionary advantage of preferring red heads over blondes is.
Humans are extremely complex, in a chaos system way. We have plenty of attributes that are not optimal for reproduction of the species, but they exist because they don't kill us off. But evolution is dumbed down for teaching purposes, even in undergraduate classes. People still recite "survival of the fittest" as if it's some sort of law. Others talk about "higher" species or "more evolved", which is nonsense.
As for monogomy, research among cultures around the world do show a consistent view that is "mostly" monogamous. Ie, serial monogamy with occasional cheating on the sly. That's universal. Yes, there are examples of cultures with polygamy, but even in those societies the polygamy is rare and when it occurs it is due to societal pressures (ie, a severe shortage of one gender, usually men due to wars), and at other times is restricted to just high class members of society (ie, to have more than one wife is proof that you are wealthy).
Long ago, I was at a good friend's house waiting for him when his wife asked me to help her with some small task that her husband normally would have done. So I did the work, and when I was done she thanked me, saying "The only thing better than having one husband is having two husbands!"
I immediately replied, "The only thing worse than having one wife is having two wives."
No, he's correct.
That is complete nonsense. We are seeing the results of social pressure to be monogamous; it is not genetic.
Just look at history for 1000's of examples to the contrary. Monogamy is a very recent phenomenon.
These studies are a huge disservice to humanity that attempt to "force" a point of view on people.
It's also reasonable to assume that infanticide may have more attribution to infant mortality than deliberate action by another male.
People who produce this junk are really missing so much of the picture.
Being a father of 4, I love those whipper snappers like crazy, even when being annoying, noisy, crying, mean. Other people's kids? Little turds can go the hell if they act like that. Shut them up and get the them the F outta my face. Of course I never say that to anyone and have the higher level thinking to take a step back and get some sympathy. But the initial instinct is there, hating other peoples' childrens' antics. Perhaps a latent instinct still at play.
Yeah, yeah, misogyny is the buzz-word of the day ... which really means "if you challenge anything that could be construed to challenge a woman in any way for any reason, I'll pull out the misogyny card so that I don't need an argument". The term is about as robust as "discrimination" (which means "to choose"). The power of words...
Anyway, a friend of mine taught in Papua New Guinea for about 10 years back in the 80s. He lived there for that time (other than the occasional holiday). He was not a missionary - he was there for education programs. This is roughly what he told me a few years back (and re-confirmed when I asked him again)...
The men tended to stay with the men, the women tended to stay with the women. There was only a loose "sexual" association between men and women - and the offspring (when the men got randy) belonged to the community rather than a couple. The kids would go with whatever adult they wanted to stay with, sometimes months at a time. Over time, this social structure was forcibly changed by the missionaries to reform these hethens.
Now, this social structure was not monogamous in ANY sense of the word and involved little or no infanticide. Interestingly, it mimics (loosely) some aspects of Indonesian culture, although Indonesian culture has also been "westernised" to a degree, although I did see this sense of "community" that you don't get in the west ... front doors left open, people just coming and going into other's houses, kids staying at other families' house for weeks at a time - it was amazing to see.
Feel free to call me a misogynist too, since it's popular to throw buzzwords around. Whenever I hear the "m" word, my "wanker alert" light goes off.
Not really. In a species with a relatively long gestation period and few offspring per litter, the limiting factor in population growth is the females. A primate female can only produce a very limited number of children over her lifespan (especially compared, for example, to rodents) and a significant fraction of those won't survive to adulthood anyway. A reproductive strategy that involves killing even more of them off is going to leave the tribe very weak and so the survivors may have benefitted from the process, but that only matters in evolutionary terms if they survive long enough to breed, and do so in comparable quantities to others with different strategies.
I am TheRaven on Soylent News
That's the drawback of the mod system, sometimes it reinforces a cultural/sexual/religious/political bias to someones personal agenda, rather than modding the content.
Personally I think monogamy happened because, after the sex, now you have to see to the needs of two or more screaming ,weepy, hormonal women who want to eat, have new clothes, go to the river/fire/gathering NOW! Right damn NOW! Early man could even see the need to filter this down to one at a time in spite of sex.
Then Cheating was born, which later spawned lawyers, so even a good fix still has an unavoidable drawback.
*Repent!Quit Your Job!Slack Off!The World Ends Tomorrow and You May Die!
It's worth noting that one of the reasons for severe decline of lions has been slowness evolutional response to human hunting factor (they seek mainly alpha males). Essentially every time one dies, the entire pride suffers a bout of infanticide, which is the key reason for decline of lions in the areas where they are hunted. If it was just alpha male deaths caused directly by humans, lions as species would have far less problems.
It's a pretty good microcosm of small tribal community and is somewhat relevant to humans as well.