Group selection

[GeoffP]

So: is it still the boogeyman that it was when I was a PhD student? We were regularly lectured on the tomfoolery of the group-ists, complete with a Two Minutes' Hate directed at GC Williams.

What's the opinion of the biologists on here? Anyone care to comment? I have to admit...it's quite reasonable. Lines clearly go extinct. It doesn't seem any less arbitrarily applied than individual fitness, save that it probably often involves major environmental changes bordering on catastrophic. Or does it? Opinions?

 

[Enmos]

I have trouble visualizing why group selection would be necessary.
Could you tell me why you think it is necessary to exist?

 

[GeoffP]

I don't know that you could call it "necessary". Why would you say "necessary"? Are you saying that all selection is on individuals so that the term isn't necessary?

 

[Enmos]

I don't know that you could call it "necessary". Why would you say "necessary"? Are you saying that all selection is on individuals so that the term isn't necessary?

Group selection is an idea to explain how groups evolve over time, right?
I'm asking why the idea of group selection is necessary to explain evolution, as it seems 'individual selection' would suffice.

 

[GeoffP]

Yes - and no.

It essentially boils down to fixed differences in state between taxons. You could call, say, the failure of dinosaurs to survive a culmination of individual selection, but in point of fact it seems much more parsimonious to attribute this failure to 'fixed' phenotypic/genotypic states shared by all members of a group. When you have these mass wipeouts, it seems simpler and more accurate/appropriate to say that the taxon (group) had a poor fit with their altered environment. One could describe it as individual selection, but it seems dishonest since the difference in survival is common to the taxon overall. This is my contention.

 

[Trooper]

Hmm… another G-word that’s avoided in science.

Is group selection about to make a major comeback this year with Edward O. Wilson’s new book “The Social Conquest of Earth”?

Now joined with gene selection, individual selection, and kin selection, it's called multi-level selection. I thought that E.O. Wilson originally said that the evolution of altruism was driven by kin selection rather than group selection. :shrug:

E.O. Wilson “The Social Conquest of Earth” – Fora TV

Religion, evolution, and the ecstasy of self-transcendence-YouTube

 

[wellwisher]

Isn't there survival of the individual and survivial of the species. Would survival of the species be connected to the group?

For example, when male animals compete for breeding rights, herd animals rarely battle to death. But solitary animals like the make lion, will. The firstis based on the group/species and second on the individual.

 

[Buckaroo Banzai]

What sort of group selection? As far as I know there's group selection as the selection for a behavior that benefits the whole group (perhaps more commonly "kin selection", or as a extrapolation of it), as opposed to more selfish/individual behavior and selection for individual reproductive advantage, and there's the group selection that's perhaps more commonly "species selection", where regardless of any mutualistic behavior being selected, one group is eventually selected over other in the same territory.


I don't know. The latter type is far more likely or at least much less controversial I guess. I think it happens quite often. The former I don't know, whatever some realistic mathematical models say. I'd guess it varies depending on several parameters.

 

[Yazata]

So: is it still the boogeyman that it was when I was a PhD student? We were regularly lectured on the tomfoolery of the group-ists, complete with a Two Minutes' Hate directed at GC Williams.

What's the opinion of the biologists on here?

I'm hesitant to participate in this thread, since I'm not a biologist. (I was a biology undergraduate back in the day, in the 1970's.) I'm nowhere up to speed on academic controversies.

Anyone care to comment? I have to admit...it's quite reasonable. Lines clearly go extinct. It doesn't seem any less arbitrarily applied than individual fitness, save that it probably often involves major environmental changes bordering on catastrophic. Or does it? Opinions?

I'm not sure what you're talking about there.

But my layman's opinion is that selection obviously takes place on the group, as well as the individual level. It shows up as changes over time in gene frequencies within interbreeding populations.

So, might evolution lead to particular members of a group enjoying less reproductive success, if that lack of individual reproductive fitness serves to increase the collective reproductive success of the population that spawns the non-reproductive forms as well as reproductive forms?

Sure. Social insects provide what appears to me to be good examples of that. In some species at least, most individuals are non-reproductive, serving the group as workers or defenders. Reproduction becomes the province of specialized individuals, ephemeral males and egg-laying queens that reproduce the next generation of all the different reproductive and non-reproductive variants.