Survival of the most attractive?

[Egg]

I've noticed that an addition that some evolution theorists make to the notion of of survival of the fittest is the survival of the most attractive.

A common example used is the peacock. The point raised is that the bigger and more illustrious the peacock's tail is, the more likely he is to attract peahens and therefore pass on his genes. So over generations, peacocks' tails evolve to become larger, even though there is no survival benefit and if anything the larger tail might even be considered a hindrance to survival.

What strikes me is that while we see this to be the case in nature, it doesn't really explain anything. We're left with the question of why certain features might be attractive to the opposite sex if they are in no way related to survival.

 

[Doubt]

That which is attractive would tend to indicate better health.

A peacock with a short tail may not be eating as well as one with a longer tail. But along the way, useless attributes such as a tendency for a longer tail may end up favored.

 

[mummymonkey]

Well presumably the proclivity to find certain features attractive is also inherited.

 

[Patricio Elicer]

I guess it has to do with Sexual Selection proposed by Charles Darwing on his theory of evolution.

 

[Third Eye Open]

sexual selection does not always have a positive affect on the survival of individuals of the species. Your example of the peacock shows this.

Unfortunately for peacocks, whatever strange attraction for large tail feathers the female peacock has, she is going to pass on to her daughter.

 

[Dymanic]

The explanation for that involves "contingent history". The QWERTY phenomenon is often invoked as an example. The arrangement of keys on a standard keyboard follows the arrangement of its predecessor, the mechanical typewriter. At this point, whether that represents the ideal configuration for a modern computer keyboard is moot; if you want to sell keyboards, your best bet is to stick with what the average user can be expected to accept. If those users can't type as fast as they might if they were using the Dvorak layout or whatever, well, that's tough, but as a marketer of keyboards, it's really not your problem.

 

[Cainkane1]

That is kinda sorta true in humans but I have noticed some rather unattractive (sometimes repellant) humans who have reproduced themselves. Being attractive is good but in primitive a good survival factor was the ability to hunt and later on farm. Being able to feed the tribe attracted mates even if you were ugly. Women even if they are less than beautiful can still attract a mate and reproduce. Thats the way its always been and thats the way it will always be.

 

[Nursefoxfire]

Just to prove your theory wrong, check out any Jerry Springer episode: The most hideously ugly people all fight over each other in order to mate with equally ugly members of the opposite sex. And THOSE members of society are the ones reproducing like rabbits!

 

[Dymanic]

Women even if they are less than beautiful can still attract a mate and reproduce.

You are defining "beautiful" here as arbitrarily as does the peahen (and Nff, following suit, defines "ugly" the same way). Where humans are concerned, the matter quickly becomes lost in nuances of culturally influenced subjectivity. That's one of the things that makes the peacock example useful. If the discussion must focus on humans, then it's pretty much inevitable that we're going to end up talking about the penis. If you want to make that organ more "efficient", equip it with a baculum (or "penis bone"), as other primates have. That "big is beautiful" pretty much goes without saying, and represents one of the few attributes probably nearly all human females have historically agreed on as being attractive in a male -- but, functionally, the human penis need not be any larger than that of any other primate in order to do its job. Furthermore, the need to achieve erection is as distinct a disadvantage as is the peacock's tail -- to the male. To the female, these may be used as indicators of health and vigor in a prospective mate.

The OP, of course, set the whole discussion on the wrong track to begin with anyway, by invoking the oversimplification: "survival of the fittest" (a phrase abandoned long ago by biologists). We're not talking about survival here, we're talking about differential rates of reproduction. By limiting the sample to Jerry Springer guests (and the segment of American society they represent), one might easily overlook the fact that in the course of human history, there have been many times and many places where breeding partners of one gender or the other were in very short supply, with the result that reproduction was indeed limited to the most successful competitors. In some of those societies, many of Jerry Springer's female guests might have been considered quite attractive, having just the sort of physical attributes that come in handy when food is occasionally scarce, and need frequently arises to carry wood, or water, or to skin bison, and where an extra hand is sometimes needed in fending off hostile neighbors with rocks and clubs.

 

[Egg]

Thanks for the answers.

I realise that the term "survival of the fittest" is an over-simplification. When I was talking about features related to survival, I would be including anything aiding survival of the species, so health, fertility and looking after the young would be included.

For such things as wealth, intelligence, broad hips or big muscles in humans, there are clear survival, reproductive or child rearing reasons why such things might be attractive. I've even heard that studies show a correlation between symmetrical faces and high fertility. But, for instance, why might a singer or a poet be attractive?

I think that often there are just reasons we haven't thought of. Perhaps the peacock with big tail feathers is able to scare off predators with his fake eyes and larger appearance and therefore better adapted to survive. There are however plenty of other examples of bright colours and certain bird songs which appear to give no benefits.

Is the contingency history explanation essentially saying that something arbitrary came into the mix and species just assimilated that into how they adapted and evolved?

 

[Dogdoctor]

Often genes have more than one function, however it is the overall survival of a species that results from evolution. This survival is due to all of the genes acting together, not just a gene for bigger tail feathers in peafowl. If a gene develops that allows individuals with a certain aesthetic reproduce more frequently and this resulted in reduced survival of offspring, other genes would have an advantage in the interbreeding population and so would keep the gene for the certain aesthetic from becoming too widespread or if not the species may become extinct. If it did not result in reduced survival of offspring then it would become the standard eventually.

 

[drkitten]

For such things as wealth, intelligence, broad hips or big muscles in humans, there are clear survival, reproductive or child rearing reasons why such things might be attractive. I've even heard that studies show a correlation between symmetrical faces and high fertility. But, for instance, why might a singer or a poet be attractive?

To be a singer or poet requires high intelligence (and specifically high verbal fluency, which is of course part of intelligence). As a matter of fact, it's hard to judge "intelligence" in any other way than through behavioral observation.

If you accept that "intelligence" is a valuable trait, then it makes sense both that intelligent people would have evolved to display their intelligence to potential mates, and that potential mates would have evolved to find such displays attractive.

 

[Mark6]

What strikes me is that while we see this to be the case in nature, it doesn't really explain anything. We're left with the question of why certain features might be attractive to the opposite sex if they are in no way related to survival.

Keep in mind that evolution works on an individual, not on a species. Big tail of a male peacock advertises health. Hens who mate with him have more chicks, both male and female. Male chicks inherit big tails. Females inherit attraction to big tails. Runaway selection for bigger and bigger tails results, until the tails any bigger would be a detriment to male's survival. Actually, they are already a detriment to male's survival -- runaway selection stops when reproductive benefits of a big tail are just balanced by the penalty of added predation. Yes, peacock species as a whole would benefit if the whole "big tail/attraction to big tail" thing disappeared. But every big-tailed individual benefits from it -- so it stays.

Likewise, male lion's proclivity to kill and eat his rival's cubs after taking over the pride is detrimental to lion species as a whole, but benefits the individual. Similar examples are very common.

 

[Ziggurat]

So over generations, peacocks' tails evolve to become larger, even though there is no survival benefit and if anything the larger tail might even be considered a hindrance to survival.

Survival rates for many animals are much higher in adulthood than in adolescence. My guess is that by the time a male peacock reaches adulthood, surviving isn't really a struggle (until it gets too old), so the cost of large tailfeathers for the male may be small. But in order to grow that large plumage, it's got to be healthy (as mentioned before). Thus while it provides the male with no direct benefit, it serves to signal to the female that it's healthy and thus has good genes, and that if she mates with it, her offspring will benefit from the good genes that made him capable of growing such a luxuriant plummage. And if chickhood is where the primary risk to survival is, then increased survival rates during this time period could easily be worth any cost later in life to her male offspring.

 

[plumjam]

Is there any evidence which suggests that peacocks with bigger tails are, on average, more healthy/fertile than peacocks with smaller tails?
Or are people just assuming this to be the case?

 

[Ziggurat]

Is there any evidence which suggests that peacocks with bigger tails are, on average, more healthy/fertile than peacocks with smaller tails?
Or are people just assuming this to be the case?

I don't think that's the claim. It isn't necessary for bigger tails to mean healthier, it's enough that big tails means healthy. The bigger part just makes that assesment more obvious to the female.

 

[plumjam]

f the discussion must focus on humans, then it's pretty much inevitable that we're going to end up talking about the penis. If you want to make that organ more "efficient", equip it with a baculum (or "penis bone"), as other primates have. That "big is beautiful" pretty much goes without saying, and represents one of the few attributes probably nearly all human females have historically agreed on as being attractive in a male -- but, functionally, the human penis need not be any larger than that of any other primate in order to do its job. Furthermore, the need to achieve erection is as distinct a disadvantage as is the peacock's tail -- to the male. To the female, these may be used as indicators of health and vigor in a prospective mate.

???
Kindly close the other 56 open tabs in your browser.

 

[Fiona]

If the discussion must focus on humans, then it's pretty much inevitable that we're going to end up talking about the penis. If you want to make that organ more "efficient", equip it with a baculum (or "penis bone"), as other primates have. That "big is beautiful" pretty much goes without saying, and represents one of the few attributes probably nearly all human females have historically agreed on as being attractive in a male

Do you have any evidence for this? I find it quite an odd statement, but I am interested in what support there is for it

 

[Egg]

To be a singer or poet requires high intelligence (and specifically high verbal fluency, which is of course part of intelligence). As a matter of fact, it's hard to judge "intelligence" in any other way than through behavioral observation.

If you accept that "intelligence" is a valuable trait, then it makes sense both that intelligent people would have evolved to display their intelligence to potential mates, and that potential mates would have evolved to find such displays attractive.

I agree that a skilled poet shows a certain type of intelligence, but whether that brand of intelligence over a more practical type is beneficial to survival is debatable. As for singing ability, the evidence in the tabloids doesn't suggest much of a correlation with intelligence.

ETA Having put forward the example in the first place, I do agree with Dymanic that human behaviour isn't really the best example to look at due to various cultural influences.

 

[Dymanic]

Is the contingency history explanation essentially saying that something arbitrary came into the mix and species just assimilated that into how they adapted and evolved?

Pretty much. Consider the "founder effect": a pregnant female gets washed up on the beach on an island where none of her kind have ever existed. Her progeny may carry traits that are irrelevant to life in the new environment. But if those traits are targets of sexual selection, they may persist despite no longer having any utilitarian value.

Is there any evidence which suggests that peacocks with bigger tails are, on average, more healthy/fertile than peacocks with smaller tails?
Or are people just assuming this to be the case?

With the peacock's tail, "bigger" is a bit of an oversimplification. The female's preference is for a greater number of ocelli (the eye-like markings that appear in the tail). (And yes, it has been studied). But it's not just that, either; the display behavior of the male is also important. It seems fairly obvious that the tail represents an investment in resources which could have been utilized otherwise, and that the tail could as easily be compromised by poor health during development as, say, the musculature of a human male -- but even if the sickly peacock could produce an elegant tail, he probably couldn't perform the display as well as a healthy male. At some point, it's not going to be possible to eliminate every trace of assumption in reaching these sorts of conclusions. As Ziggurat and Mark6 have indicated, evolution in the peacock tail probably maxed out long ago, making it a simple "pass/fail" test at this point.

Do you have any evidence for this? I find it quite an odd statement, but I am interested in what support there is for it.

Call it a hypothesis. Richard Dawkins and others have written... uh... at length about this. Dang, the opportunities for levity along this tangent are getting hard... to resist.