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Question about natural selection


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I am wondering if "survival of the fittest" is actually what determines selection. I have read that it is survival of the fittest to reproduce or selection of the most successful at reproducing.

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Survival of the fittest is true, when you realize that the benchmark for fitness is evolutionary terms is number of viable offspring. It has nothing (directly) to do with strength, speed, health etc.

 

Some of those qualities might help you reproduce more, but they also might not depending on the situation, and when they don't, they don't have anything to do with evolutionary fitness.

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Survival of the fittest is true, when you realize that the benchmark for fitness is evolutionary terms is number of viable offspring. It has nothing (directly) to do with strength, speed, health etc.

 

Some of those qualities might help you reproduce more, but they also might not depending on the situation, and when they don't, they don't have anything to do with evolutionary fitness.

 

"Fittest" is unfortunately one of those terms that's vague enough to satisfy a media sound byte. It allows for too much interpretation that has nothing to do with evolution.

 

I once heard a guy loudly proclaim "Survival of the fittest!" after he chugged his large beer at a bar. He was so blotto I doubt he was able to pass his genes along that night.

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"Fittest" is unfortunately one of those terms that's vague enough to satisfy a media sound byte. It allows for too much interpretation that has nothing to do with evolution.

 

I once heard a guy loudly proclaim "Survival of the fittest!" after he chugged his large beer at a bar. He was so blotto I doubt he was able to pass his genes along that night.

Well part of being evolutionary successful is being sexy, attracting a mate and after all, drinking is cool and inhibitory to sound judgement, so....

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Well part of being evolutionary successful is being sexy, attracting a mate and after all, drinking is cool and inhibitory to sound judgement, so....

Actually, yes, this is a perfect example. Getting regularly drunk and engaging in risky behaviors makes you both kind of stupid and also much more likely to (accidentally) reproduce.

 

Thus increasing the selective fitness of traits that lead to going out and getting plastered regularly.

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Actually, yes, this is a perfect example. Getting regularly drunk and engaging in risky behaviors makes you both kind of stupid and also much more likely to (accidentally) reproduce.

 

Thus increasing the selective fitness of traits that lead to going out and getting plastered regularly.

If were getting serious again, it seems possible that this was a selective pressure, possible. Not sure how long we have been drinking. But as you say drinking may co-opt in to a more general concept of evolution of risky behaviours which would ofcourse have a complex origin, but you have to start speculation somewhere.

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We must be careful here. The idea of fitness has been debated for a long time with it (very roughly) boiling down to two concepts, one championed by Gould and Eldrege (via G.G. Simpson and others) and the other by Richard Dawkins, W.D. Hamilton and others. The Gouldians (if I may) argued that an individuals reproductive success is selected based on a variety of traits, such as the tendency to engage in "risky behaviors" cited above. However, the dominant idea today is that it is not individuals that are the unit of selection, it is the genes themselves.

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We must be careful here. The idea of fitness has been debated for a long time with it (very roughly) boiling down to two concepts, one championed by Gould and Eldrege (via G.G. Simpson and others) and the other by Richard Dawkins, W.D. Hamilton and others. The Gouldians (if I may) argued that an individuals reproductive success is selected based on a variety of traits, such as the tendency to engage in "risky behaviors" cited above. However, the dominant idea today is that it is not individuals that are the unit of selection, it is the genes themselves.

Agreed, care is needed.

 

Fitness was a term developed in the academic period that championed the individual as the unit of selection. The gene centric view doesn't dismiss the individual but co-opted it, and with the concept of the gene as a unit for selection was able to provide an even better explanation for many difficult evolutionary conundrums. Yet genes still come together to build bodies, and largely they succeed or fail together (allowing us to get away with not making your distinction), so evolutionary fitness of that collective of genes is still a relevant concept.

 

Even if it useful to think in terms of success/fitness for the genes that code for risky behaviours.

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However, the dominant idea today is that it is not individuals that are the unit of selection, it is the genes themselves.

My impression was that the pendulum had definitely swung the other way. Do you have any citations to review articles that would confirm your thinking.

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My impression was that the pendulum had definitely swung the other way. Do you have any citations to review articles that would confirm your thinking.

Not an easy thing to cite. Not really sure that there is any consensus building centre you can go to for evolutionary biology, after all, your looking for an academic pulse. There is definitely still plenty of disagreement. However, I would definitely agree with MEC1960 that the gene centred view dominates the academic field and is the most influential, but to get a feel for it I think you just have to read widely.

 

The thing is the distinction is not strictly important in many instances when discussing adaptations or explaining evolutionary causes of most biological phenomena, so that it can allow the debate to simmer or be left untouched in much evolutionary work.

Edited by tantalus
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Tantulus - you're correct that for most purposes of understanding selection the distinction is not critical though for pedagogical reasons I do think it is important to always keep it in mind. Too many "just-so" stories are told about selection because this key idea is forgotten.

 

Ophiolite - I don't think that pendulum has swung at all. Quite the opposite, in fact. There is still a lot of heated arguments about it, particularly recently among physiologists but also from those still clinging to ideas like group selection, but most of those stem from a misreading (or misunderstanding) of the selfish gene concept. That's not to say that the debate is settled - far from it - just that the gene-centrist view of selection has the upper hand. FTR - I don't have a dog in this fight. I do accept the evidence of the gene-centric view but accept also that there may be exceptions.

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Ophiolite - I don't think that pendulum has swung at all. Quite the opposite, in fact.

Since my reading of biology research papers is highly selective it is entirely possible I am selecting a sub-set of biologists who favour selection at individual, or even group level. I would still like to see some review articles that confirm the perception you and tantalus have.

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