Posted by Rhys Ursuliak (9)
Wednesday, November 30, 2011
Monkeys Mother Wingmen
How often do you find your mother setting you up with a date? For a young male muriqui monkey of Brazil, his mother is the best wingman he could hope for. Troops of muriquis are led and run by a matriarch. This older female can live upwards of thirty years, and governs the mating that happens within her troop. Because of this, there is no competition for male dominance in mating. Instead, the matriarch's policy seems to be "everyone gets a share." Although some males are preferred and will have greater reproductive success, all the males will get the chance to pass their genes along. This raises the question: "if everyone has a chance to pass on their genes, doesn't that take natural selection out of the picture?" If the males are not competing or being selected for, then detrimental traits could be passed along, harming the overall population. This species is severely endangered, so this could be part of the reason.
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I enjoy that you posed a question.
ReplyDeleteI would have to say that in a way the mother is forming her own "artificial" selection as well as natural selection. She chooses who each male mates with and because she chooses the outcome of the offspring varies.
It is also interesting to "hear" that the species is endangered. Are there any conservation groups attempting to intervene? Maybe not disrupt the troops, but some way help them.
Posted by: Em Arsenault
I find it pretty hard to believe that all the males will have the same chance to pass on their genes. Wouldn’t having the mother as a wingwoman count as an evolutionary advantage for the monkeys? I would imagine that it takes some sort of special trait for that one particular mother to become the matriarch of the troop and maybe by having her son pass genes on, the trait for becoming the matriarch would be passed on as well? I feel like more research needs to be done on this species to appreciate the full extent of what is going on.
ReplyDeletePosted by James Lin
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ReplyDeleteHi Rhys,
ReplyDeleteThis is such a good topic. Its so sad that their sociality could be the cause of their decline. I guess evolution and natural selection favors the theory that not everyone can win.
I feel like that this could be an example of a Darwinian puzzle. But if natural selection is at play then it should select against the detrimental traits and they would eventually die out. Also you did say that some have better reproductive success than others so that is natural selection at its finest. It might be that natural selection is not as strong as in other animal population due to their sociality.
They could be endangered because of human causes, or there is not enough food also.
Posted by Whitney Huynh
I agree that unfavorable traits are more likely to be passed along however this wouldn't eliminate natural selection. You said some males reproduce more than others because they are more desired. Their traits then will slowly become more prominent in the population. Also detrimental traits can still be taken out of the gene pool if they are severe enough to kill the individuals before reproductive age.
ReplyDeletePosted by Michael Thomas
I agree that while the opportunity for all males to mate might make undesirable genes persist in the population longer than they would in a population without this mating system, the fact that the more desirable males have a disproportionately high reproductive rate would in the end allow natural selection to affect the population, albeit possibly at a slower rate than it works in other species populations. However, you are definitely right that this could possibly be a factor in their status as an endangered species. I wonder if there are any other factors at work that could be contributing to the problem?
ReplyDelete- Posted by Johanna Brophy
WOW this is really cool. I have never heard of a system where the female is not only dominate but controls who within the group mates with who. I also wonder why this system is more beneficial then the mating displays but species such as the birds of paradise.
ReplyDeleteIt does not seem likely that this characteristic was not selected for evolutionary. So why was it selected stumps me!
Posted By Caroline Adams
SO, do the females in the group have no say in their choice of mate either? I have never heard of this type of scenario in nature before, with one female deciding all mating. I think, however, that natural selection would in fact still exist. As you mentioned some males do have higher reproductive success, which means that although it would go slowly, there is natural selection to some extent. This may be a factor in their small remaining population, but maybe there are also other influences, such as loss of habitat or human factors. Still, it would be interesting to see if bad genes are passed along.
ReplyDeletePosted by Caitlin Descovich O'Hare
This is a very interesting means of sexual selection. So from what I gathered from your article the mother has no discrimination at all on who she is gonna help find a mate? So how does she decide who she is gonna help first? Also how does the mother pick the female for the son? I wonder if she is discriminate on certain physical traits of the female. In this case it would be male choice through the mother.
ReplyDeletePosted by Nick Gast
To Nick Gast
ReplyDeleteIt seems like the mother helps all the males equally. The main mechanism in which she facilitates mating is actually proximity. That is, males who are nearby the mother are more likely to have females attracted to them and initiate mating.
Rhys Ursuliak