Dawkins' purpose in his book The Extended Phenotype is to dash the concept that the individual is the unit of selection, that is, the idea that, among other things, individuals act in a manner as to increase copies of itself. (Ann Coulter, for example, in her crap book Godless asks why, if evolution is true, she doesn't want to have children. Once again, she has mistaken evolutionary theory for a naive "for the good of the species" caricature of evolution. I should think that organisms (i.e., Dembski) manipulating other organisms (i.e., Coulter) into believing in creationism would be a prime example of said manipulation.)
Organisms may consistently work against their own interests (inclusive fitness) through being manipulated by another organism. Examples of manipulators are angler fish and cuckoos.
Although it's easy to assume that one animal manipulating another is only a temporary phenomenon until the other animal evolves some method of fighting back (that is, that the manipulation is a "time-lag" phenomenon--see my post on constraints on perfection), in reality the manipulator can in fact succeed continuously under certain conditions. An example of this is intraspecific manipulation (manipulation within the species, particularly kin-manipulation). Examples are parents manipulating their offspring, and offspring manipulating their parents.
Altruism is defined here, in a biological sense, as a behavior that favors other individuals (their inclusive fitness) at the expense of the actor.
Dawkins believes that parents who manipulate their children have an advantage over parents who do not, but states that parents do not have any built-in advantage over their children by the mere fact of their being parents.
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Dawkins believes that parents who manipulate their children have an advantage over parents who do not, but states that parents do not have any built-in advantage over their children by the mere fact of their being parents.
Ants are interesting in this way. There are larva and adults. The larva develop into the adults (obviously) so in a way you can think of the adult morphology as an extended phenotype of the larva. (Sort of ... but bear with me for a moment on this.)
Adult ants are built in such a way that the alimentary tube that runs from their thorax to their abdomen, through which any food they consume must pass, is so small that adult ants can consume nothing at all that is not liquid.
Since adult ants can only consume liquid (not crumbs from picnics as is commonly thought) most of them have to get their nutrition from the larva.
The adult ants bring food (picnic crumbs, etc.) to the larva and feed it to them. The larva then digest this and turn some of into nutritious ant-spit that the adults eat.
Thus, the adult ants are basically waitrons that exist to serve the larva.
On top of this, there are many ants in symbiotic relationships with plants, whereby the plants provide "honey dew" (or various other names) ... basically plant-produced synthetic ant-spit. It is of course because of the larva-adult relationship that this is possible ... the existing system is adjusted slightly and exploited by the plants. The adults are essentially addicted to ant-spit, and the plants are taking advantage of this by using synthetic ant spit as a payoff for the ants providing protection or whatever other function the plants are after.
you can think of the adult morphology as an extended phenotype of the larva
This did not rock my world too much (although it's weird.) I think that Gould wrote something similar regarding primate and hominid childhood development although he did not specifically that adulthood was an extended phenotype of the child--rather, that the child was almost an independent fetus.
Thank you for taking the time to comment on this. Greg, you have so much to contribute and are certainly welcome to post here! I do not have a science degree so I'm happy to find that I am not terribly off the mark. Feel free to let me know if you want to post.
Well, the extended phenotype bit did not exactly rock my world either. I just stuck that in to fit in with the overall post.
This realization came to me during a lecture at a Cafe Scientifique session run by the Bell Mueum (for those of you in the Twin Cities ... this is worth looking up). It was a guy who pours hot metal down ant holes, then digs out the "sculpture" that results ... interesting science but a little strange.
Anyway, what blows me away is the prospect that larva controlling, developmentally, what might be a deliterious trait in mom and aunty (oops, sorry, I did not mean to make that pun, but I'll leave it in place anyway) in order to blackmail them into service.
Parent offspring conflict is a research interest of mine, so I was surprised to have never encountered this idea before...
Kristine, yes, I'd be honored to post some time.
Cheers,
GTL
Well, the extended phenotype bit did not exactly rock my world either.
But I can imagine it doing that for other people who aren't reading stuff like this. After all, most people think of the children as the extended phenotype of the parents, however accurate that is.
But after seeing The Fly (1980s version) and Jeff Goldblum consuming his liquid lunch, nothing much surprises me anymore.
Blech.
;-)
Thank you for reminding me of that disgusting scene in the Fly. Appreciate it.
Have you read any of the stuff by David Haig on parent offspring conflict? Or Bob Trivers?
PO conflict is Trivers' theory ... he first used the term and defined the math, etc. Haig's stuff is more recent and much, much spookier.
Have you read any of the stuff by David Haig on parent offspring conflict? Or Bob Trivers?
Alas, no--I only even started reading Dawkins last year. I grew up on Stephen Jay Gould, but fell away from science for a long time, until all this intelligent design nonsense.
There's so much that I want to read--but then there's all my texts for class (sigh). Gotta get on them, and Jonathan Vos Post's paper... I have some writing that I want to do...
And anytime you want me to talk about gross stuff, I'm hip. ;-) (As you may expect I'm not really "one of the girlie girls.")
And anytime you want me to talk about gross stuff ...
OK, we'll talk about gross stuff some time.
Trivers and Haig would be an area that I could post on. I don't know how much this blog, as a "Female Triumvirate" thing, is meant to orient towards 'gendered' issues. Some of this parent-offspring conflict stuff is very gendered. (actually, all of it). It is in fact asymmetries in gender that cause some of the most interesting effects.
For instance, the protein that is responsible for growing placental tissue in a fetus (the placenta is a part of the fetus, not the mother, and is responsible, essentially, for sucking maternal energy out of her) is coded for by a gene that comes from dad, not mom, in most/many mammals. (Certainly in humans). Why? How?
Ahh, that's the rub...
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