Comments on: Group Selection and the Wrinkly Spreader

By: windy

windy — Sat, 01 Mar 2008 07:21:44 +0000

...I will post a short note about them on gnxp soon.

Sounds good!

By: David B

David B — Sat, 01 Mar 2008 04:38:47 +0000

Windy: thanks. Very useful. I wasn’t aware of this team, but I have Googled them and I like what I see. They have a good homepage with links to papers, and I will post a short note about them on gnxp soon.

By: windy

windy — Fri, 29 Feb 2008 18:59:04 +0000

And indeed, some of the [other examples], like the Wilsons' reference to the territorial behaviour of female lions, seem even worse. How can anyone sensibly discuss this without mentioning that the lionesses of a pride are usually closely related?

Another blatant example was in their popular article in the New Scientist: "Genes that cause beavers to build dams are still at a local disadvantage compared with genes in beavers in the same pond that don't build dams"

For anyone still reading this thread: the work of A Gardner, SA West and AS Griffin (and other combinations) features some interesting criticism of the Wilsons and other new group selectionists.

By: David B

David B — Mon, 25 Feb 2008 02:37:04 +0000

Oh, the segregation distorter. Surely this is the classic case of a ‘selfish gene’ spreading against the interests of individuals – the very reverse of group selection as commonly understood!

By: Caledonian

Caledonian — Sun, 24 Feb 2008 10:38:11 +0000

I believe that's one of the names for it - or at least, the description here sounds exactly what I'm thinking of.

The gene spreads like a wildfire. It's the temporary barriers between different mouse populations that keep it from spreading without limit. The tendency of populations with low levels of that allele to found new groups is what maintains the species. If new populations are not constantly founded, then the allele would come to predominate. If the barriers between populations are removed, that would also be the outcome.

By: gcochran

gcochran — Sun, 24 Feb 2008 10:06:15 +0000

T-allele ?

By: Caledonian

Caledonian — Sun, 24 Feb 2008 07:09:04 +0000

J. B. S. Haldane had an idea along these lines, but W. D. Hamilton showed (roughly) that if groups are formed randomly, altruistic traits will die out (apart from recurrent mutation).That depends on how beneficial the presence of the trait is for the group, and how harmful it is for the individual.

Mice already demonstrate this form of selection, only the trait in question grossly harms the group but benefits itself – it’s the negative-space equivalent.

And… I’ve forgotten the gene’s name, again. I need to write that down someplace obvious. Or tattoo it to my forehead…

By: Robert Sykes

Robert Sykes — Sun, 24 Feb 2008 04:41:14 +0000

I should like to see some discussion of S. J. Gould’s last book “The Structure of Evolutionnary Theory,” in which he argues that selection occurs at all taxonomic levels, even those above the species level. While Gould was somewhat on the fringe in many of his ideas, he was an important figure in 20th century evolutionary theory, and his views deserve to be analyzed rather than ignored.

By: David B

David B — Sun, 24 Feb 2008 03:36:43 +0000

"why not think of group selection as a form of, or rather as having its origins in, inclusive fitness"

Occam's Razor. Why use two ways of explaining the phenomena when one will do?

"if new groups form often enough, the regenerative consequences of the founder effect will cause the trait to not only persist, but often to increase"

J. B. S. Haldane had an idea along these lines, but W. D. Hamilton showed (roughly) that if groups are formed randomly, altruistic traits will die out (apart from recurrent mutation). There has to be some way of concentrating the benefits of altruism disproportionately on other individuals bearing the genes for that trait.

By: chet snicker

chet snicker — Sat, 23 Feb 2008 11:15:53 +0000

wrinkly spreader? dat sounds like fetish porn

Sir,

Comport yourself as a gentleman!

Sincerely,
C.V. Snicker

By: Nico

Nico — Sat, 23 Feb 2008 11:02:35 +0000

wrinkly spreader? dat sounds like fetish porn

By: Caledonian

Caledonian — Sat, 23 Feb 2008 09:40:08 +0000

During evolution by natural selection, a heritable trait that increases the fitness of others in the group (or the group as a whole) at the expense of the individual possessing the trait will decline in frequency within the group. Well, yes.

But if new groups form often enough, the regenerative consequences of the founder effect will cause the trait to not only persist, but often to increase.

We don't even need to have the groups be composed of closely-related members for the trait to increase in this way.

By: Luke Lea

Luke Lea — Sat, 23 Feb 2008 07:58:01 +0000

Well, then, why not think of group selection as a form of, or rather as having its origins in, inclusive fitness, given that most groups in the paleolithic period were in fact composed of closely related individuals? Belonging to a local group becomes a proxy for kinship.

Darwin speaks of such "obvious" examples of group traits as courage in battle, to choose one that I remember. When individuals in modern societies manifest courage in battle, might this not be a trait they have inherited from their paleolithic forbears?

The point in your quote, that such traits will be come less common over time if the group is composed of unrelated individuals, is important if true. But what happens if all the individuals in a group happen to share this particular trait? Or if those who do share it have preferential access to women (hero worship and all that)?

Finally, even if the trait does gradually disappear, it is still group selection while it lasts, in the sense that groups that possess such individuals may have a better chance of prevailing in intergroup competition, even if their posterity may not. What do you call that kind of temporary "selection"?