How Exactly is Attractiveness Evolutionarily Beneficial?

Ok so one of my ongoing pet peeves is when scientists, or any one else for that matter, get so attached to an idea or a philosophy that they try to meld any data they find into that philosophy even when it doesn’t make very much sense.  I noticed this happening quite a bit in the “Antlers of Clay” chapter.  I was pleased to find that when the initial hypothesis about attractiveness – that it signaled good genes – was confronted with contrary evidence, scientists began to revise their thinking (Yay scientific method!), but then, in order to reconcile this new evidence to the assumption that any behavior present in nature must be evolutionarily beneficial, scientists came up with a bafflingly conv0luted hypothesis.  The bandwagon effect as Sapolsky calls it occurs when a particular feature is considered attractive to females and all the females of a group want to take better care of that offspring so that it has a better chance of mating in the future.

So here’s my question, who initially decides that such and such a feature is more attractive?  I mean we want to say that all the female birds jump on the bandwagon to make sure their sons get a mate, but if attraction is based on the principles of evolution why is there a bandwagon based on essentially arbitrary features in the first place?  And if there is some mechanism by which an animal suddenly “decides” that some particular feature is attractive, couldn’t they just as easily “decide”, that they would rather take care of the cute offspring, just because they feel like it, eliminating any need to explain it from an evolutionary perspective at all.  And that throws another wrench in the entire debate because wouldn’t that suggest that all of animal behavior is subject to the whims and fancies of any given species at any given moment?

Sapolsky himself calls it circular logic, but then goes on to declare that this explanation (that as we’ve established doesn’t actually explain all that much) has to be ruled out of ever subsequent study on the subject.  And another thing, while I realize that evolution can often occur very quickly, especially when it comes to more superficial characteristics like coloration etc., if these traits represent passing fads in animal attraction how is it that animals like the male peacock have evolved consistent patterns that basically define the species.  I mean that’s a pretty stable trait for something that potentially has no direct effect on survivability of the offspring.

Ok I’m finished with my rant.

2 thoughts on “How Exactly is Attractiveness Evolutionarily Beneficial?

  1. Stephanie – I enjoyed reading your post. It is interesting to think about what actually makes a specific trait more attractive in animals, especially since some of the traits, such as peacock plumage, seem so arbitrary. Based on some of what I have been learning in animal behavior I think I may be able to provide some possible answers to your questions. Even though traits deemed “attractive” may seem arbitrary, many of them actually signal higher fitness in the individuals. Going off of the peacock example, peacocks with large plumage and brighter coloration are most likely stronger and more healthy, as the acquisition of this plumage requires energy investment. Better diet could contribute to it, and if the peacock is able to eat a better diet, this probably means it is a better forager, which is a beneficial trait to be passed on to future generations. Females may have evolved to pick out these “attractive” traits because they mean higher fitness in their young. Therefore, natural selection would result in more peacocks that have more “attractive” plumage, and the trait would remain stable in the population. Similarly, in the lyrebird females chose males with more elaborate mating rituals. The more elaborate a male’s ritual, the more time he is able to dedicate to it, which means more energy expenditure on the part of the male that takes energy away from other processes such as growth and feeding. If the lyrebird is able to invest more energy into mating, he thus likely has higher fitness. I hope this is somewhat helpful in addressing your questions!


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