Can natural selection select for genes based on their utility at a group level?

[Queequeg]

Eusocial species share close kin relationships to keep natural selection from breaking down the social order through selfish behavior. Our social amniote species doesn't have anywhere near the degree of kin relatedness (either today or in the distant past) in our social groups of any eusocial species. That is a good reason homosexuals can't be a part of this.

The optimal size of a human group before agriculture was tiny, and often kinship bound.  IIRC somewhere between 50 and 150.  I think there would still be obvious advantages to having fit, sterile or disinterested in reproduction able bodied men about; the fashionable, funny uncle with a *special* relationship with another uncle could take care of children whose parents have died, and would still be useful in conflict and finding food. 

Could also presumably be some kind of population control; this would seem to fit with suggestions that boys are more likely to be gay for every older brother they have.

[Queequeg]

How would that work?  Homosexuality gets carried on through straight women?

X woman and Y man have 6 children, 3 boys, 3 girls.  1 boy is gay.  When X and Y are devoured by sabre tooth tigers, the gay boy can help take care of his siblings and eventually his nieces and nephews, therefore the rest of his family thrives. 

It also strikes me as sort of self selective to point out that families that have more children are likely to have more gay ones.

Statisticians aren't stupid. 

[DGuller]

If there wasn't some kind of evolutionary pressure for it, or if it wasn't net beneficial or at least neutral for a species, it presumably would have been weeded out.

Sometimes arguments like that remind of me the joke about two efficient market theorists seeing a hundred dollar bill on the sidewalk and not picking it up, because if it were real, someone would've already taken it.

[Queequeg]

Sometimes arguments like that remind of me the joke about two efficient market theorists seeing a hundred dollar bill on the sidewalk and not picking it up, because if it were real, someone would've already taken it.

I guess it is also possible that somehow the proclivity towards homosexuality is thrown in there at some point; perhaps whatever process leads to homosexuality can, in milder form, result in extremely fecund males.   

[garbon]

It seems like it would make more sense for a gene to exist to make sure some individuals are sterile.  As after all, homosexuals aren't incapable of creating offspring, their just not inclined towards it.*


*which here in the west is again in flux as people get surrogates and the like.

[alfred russel]

Eusocial species share close kin relationships to keep natural selection from breaking down the social order through selfish behavior. Our social amniote species doesn't have anywhere near the degree of kin relatedness (either today or in the distant past) in our social groups of any eusocial species. That is a good reason homosexuals can't be a part of this.

The optimal size of a human group before agriculture was tiny, and often kinship bound.  IIRC somewhere between 50 and 150.  I think there would still be obvious advantages to having fit, sterile or disinterested in reproduction able bodied men about; the fashionable, funny uncle with a *special* relationship with another uncle could take care of children whose parents have died, and would still be useful in conflict and finding food. 

Could also presumably be some kind of population control; this would seem to fit with suggestions that boys are more likely to be gay for every older brother they have.

You are still wrong--eusocial species have developed systems that cause hyper degrees of relatedness that are not matched in any human (or other primate) group. Most eusocial species have special reproductive systems involving chromosomal number differences between sexes to facilitate extreme kin relationships that aren't in humans.

[alfred russel]

Not all traits are breed for (or bred against). Many traits are just incidental.

Very debateable--at least in the long term.

Genetic and evolution is way more complicated the good traits survive, bad traits die off.

Very true.

[Queequeg]

You are still wrong--eusocial species have developed systems that cause hyper degrees of relatedness that are not matched in any human (or other primate) group. Most eusocial species have special reproductive systems involving chromosomal number differences between sexes to facilitate extreme kin relationships that aren't in humans.

This seems to be a debate over degrees more than anything else.  Obviously we aren't predisposed towards a complex social existence as much as eusocial arthropods, but I think we have gone through a similar process in that primates since the Eocene have become increasingly social animals, ultimately resulting in humans who are capable of extremely complex vocalizations and other forms of communication, empathy and a division of labor.  In this respect, I think we have more in common with, say, bees, who have complex hierarchies and divisions of labor; we've evolved into this niche over the last say 5 million years.  Only our females aren't ten times bigger nor can they lay thousands of eggs.....yet.

[Queequeg]

AF, I remember you asking in a thread once if diapsids evolved from synapsids or separately from anapsids.  Did you ever get an answer? I wondered about that too.

[alfred russel]

AF, I remember you asking in a thread once if diapsids evolved from synapsids or separately from anapsids.  Did you ever get an answer? I wondered about that too.

No, I emailed a couple professors from Harvard that specialized in that era, and only one emailed me back to say he didn't know. I gave up.

[alfred russel]

You are still wrong--eusocial species have developed systems that cause hyper degrees of relatedness that are not matched in any human (or other primate) group. Most eusocial species have special reproductive systems involving chromosomal number differences between sexes to facilitate extreme kin relationships that aren't in humans.

This seems to be a debate over degrees more than anything else.  Obviously we aren't predisposed towards a complex social existence as much as eusocial arthropods, but I think we have gone through a similar process in that primates since the Eocene have become increasingly social animals, ultimately resulting in humans who are capable of extremely complex vocalizations and other forms of communication, empathy and a division of labor.  In this respect, I think we have more in common with, say, bees, who have complex hierarchies and divisions of labor; we've evolved into this niche over the last say 5 million years.  Only our females aren't ten times bigger nor can they lay thousands of eggs.....yet.

It isn't a difference of degrees--I think it is fundamental. Eusocial species appear (at least at first glance) to overcome limits of selfish behavior through the development of extreme kin relationships. We don't have the extreme kin relationships, and aren't eusocial.

[Viking]

It's called group selection. Remember you possess many of the same genes as your group or society.

http://en.wikipedia.org/wiki/Group_selection

As for a gay gene if there is one. It doesn't necessarily result in diminished reproduction. It might be individually beneficial and only become the gay gene when interacting with some other otherwise beneficial gene. Gayness might be an extreme expression of a trait that is otherwise beneficial, like some have suggested a connection between the god gene and epilepsy, one beneficial, the other harmful. http://www.physicsforums.com/showthread.php?t=57809

[Ideologue]

Eusocial species share close kin relationships to keep natural selection from breaking down the social order through selfish behavior. Our social amniote species doesn't have anywhere near the degree of kin relatedness (either today or in the distant past) in our social groups of any eusocial species. That is a good reason homosexuals can't be a part of this.

The optimal size of a human group before agriculture was tiny, and often kinship bound.  IIRC somewhere between 50 and 150.  I think there would still be obvious advantages to having fit, sterile or disinterested in reproduction able bodied men about; the fashionable, funny uncle with a *special* relationship with another uncle could take care of children whose parents have died, and would still be useful in conflict and finding food. 

Could also presumably be some kind of population control; this would seem to fit with suggestions that boys are more likely to be gay for every older brother they have.

Spitballing, if this is the case, it could also be a mechanism for managing not only population but also intragroup rivalry, by eliminating male competitors for the limited amounts of female breeding stock, who may be dominated outside of social-contract-enforced monogamy by the strongest males.

[Josquius]

Gayness is genetic?
I thought studies had proven it was just a small factor?


Thinking of it was...I just can't see a way to make it work unless you tie in homosexuality with submissive behaviour or other such things (which of course isn't so).
I was thinking down lines of only the alpha male being able to breed and so the other straight males would challenge him and die whilst the gays would accept this- but this would still end up with the gays not breeding to prove gayness is a positive attribute....No other ideas come to mind.

[Valmy]

X woman and Y man have 6 children, 3 boys, 3 girls.  1 boy is gay.  When X and Y are devoured by sabre tooth tigers, the gay boy can help take care of his siblings and eventually his nieces and nephews, therefore the rest of his family thrives.

What does that have to do with anything?  It is not like the nuclear family was around during the Sabre Tooth tiger days.  I am pretty sure everybody in the group would have helped out.

I was not even denying it might not be somehow advantageous to have gay men (and women....) around I just didn't get the correlation between ferility and gayness thing.

Statisticians aren't stupid.

Yet strangely 95% of all statistics posted on the internet are.