Homosexuals

[N35t0r]

I've heard of "gay uncle" theories that say it increases the survivability of offspring, but why aren't there more gays, then?

(note: actual numbers totally made up)

Diminishing returns. One 'gay uncle' for, say 40 'nephews', if he increases the odds of them surviving to child-baring age by 20%, is the equivalent of him having 4 kids that survive, and that is only if there is no extra strain on resources due to the extra children (unlikely, and unless the clan has some sort of power, the extra resource strain will affect his clan worse than the other clans, so it's comparatively more detrimental to them).

On the other hand, 4 'gay uncles' for 10 nephews would need to increase the odds by 80% each for it to be the same for them as having 4 surviving kids. So, above a point, being gay does not increase the likelihood of your genes passing on.

[Kidlicious]

Having kids will also mean more competition for resources, so it lowers propagation chances for them and for the rest of the family group (at some point, having more children might actually lower the chances of your genes propagating).

Yeah right. Tell that to rabbits.

[N35t0r]

Yeah right. Tell that to rabbits.

Strawman. Obviously this applies to rabbits too, but also obviously the ideal number is not the same as with humans.

You're saying that if rabbits had 50 offspring each litter, the percentage that died would be the same as now? And if they only had 4? Wouldn't food at least be more plentiful? It's a balancing act: more kids, less resources for each. There's an optimum.

[Kidlicious]

Strawman. Obviously this applies to rabbits too, but also obviously the ideal number is not the same as with humans.

You're saying that if rabbits had 50 offspring each litter, the percentage that died would be the same as now? And if they only had 4? Wouldn't food at least be more plentiful? It's a balancing act: more kids, less resources for each. There's an optimum.

I don't think this theory of yours jives with facts. Rabbits and humans, along with I imagine most other species, compete for resources with other species. More babies is always better. Also, within the species animals are competing with each other to continue their genes. Those animals who have more babies obviously do better because they have more offspring to compete.

[Kidlicious]

Strawman. Obviously this applies to rabbits too, but also obviously the ideal number is not the same as with humans.

You're saying that if rabbits had 50 offspring each litter, the percentage that died would be the same as now? And if they only had 4? Wouldn't food at least be more plentiful? It's a balancing act: more kids, less resources for each. There's an optimum.

If they had only 4 bunnies and another species that was in competition for the same resources had more offspring the rabbits would be at a disadvantage.

[N35t0r]

If they had only 4 bunnies and another species that was in competition for the same resources had more offspring the rabbits would be at a disadvantage.

Then why don't all species spawn off babies every second? It's clearly the superior choice, according to you? Why do species like humans and elephants who only have one kid at a time and gestate for almost a year still on earth, when there's rabbits and dogs to out-breed them?

[onodera]

(note: actual numbers totally made up)

Diminishing returns. One 'gay uncle' for, say 40 'nephews', if he increases the odds of them surviving to child-baring age by 20%, is the equivalent of him having 4 kids that survive, and that is only if there is no extra strain on resources due to the extra children (unlikely, and unless the clan has some sort of power, the extra resource strain will affect his clan worse than the other clans, so it's comparatively more detrimental to them).

On the other hand, 4 'gay uncles' for 10 nephews would need to increase the odds by 80% each for it to be the same for them as having 4 surviving kids. So, above a point, being gay does not increase the likelihood of your genes passing on.

A real nephew has what, 12.5% probability to have the gay gene? You would need a whole lot of nephews to care for if you want the caring effect to match the effect of caring for your own children.

[N35t0r]

A real nephew has what, 12.5% probability to have the gay gene? You would need a whole lot of nephews to care for if you want the caring effect to match the effect of caring for your own children.

Only twice as many. Ideally, you'd need more, since you won't be giving all of your attention to everyone of them.

Your siblings share 1/2 of your genes, and their kids have 1/2 of theirs. So you have 1/4 of your genes in common with your nieces and nephews. Your kids have 1/2 of your genes. So, genetically speaking, it's the same if one of your kids passes on his gene than for two of your nephews to do so.

[Jon Miller]

The 'uncle' hypothesis doesn't make any sense considering the other animal species in which homosexuality is observed. Including animals where there is no social structure and animals where 'non-breeding uncles' would have no effect.

Basically, there is no reason to consider the hypothesis as anything more than something to discuss over beers at the pub.

JM

[Jon Miller]

The 'uncle' hypothesis doesn't make any sense considering the other animal species in which homosexuality is observed. Including animals where there is no social structure and animals where 'non-breeding uncles' would have no effect.

Basically, there is no reason to consider the hypothesis as anything more than something to discuss over beers at the pub.

JM

[N35t0r]

I don't know. It wouldn't be the first time a particular gene/trait survives because of new adaptations/behaviours. I'm not saying that that is why homosexuality exists, but it would be a good explanation as to why it survived in humans/other social animals.

[Jon Miller]

Why would it be?

JM

[Jon Miller]

There doesn't seem to be any supporting evidence.

And if my memory is correct, there is evidence to the contrary.

This seems to be an example of a 'just so' story, which is one of the problems in evolutionary psychology/biology.

http://www.newyorker.com/arts/critics/books/2012/09/17/120917crbo_books_gottlieb

http://link.springer.com/article/10.1007%2FBF00389657?LI=true

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

JM

[N35t0r]

Why would it be?

JM

My argument is that, IF ( 'gay uncle' increased the likelihood of survival of his nieces and nephews sufficiently AND homosexuality is a genetic condition ) THEN this would mean some positive selection of the gene.

I wouldn't really know if the first one is strong enough to be true, and I'd never say that this is the only (or even the most important) factor affecting the survival of the gene.

[Kidlicious]

Then why don't all species spawn off babies every second? It's clearly the superior choice, according to you? Why do species like humans and elephants who only have one kid at a time and gestate for almost a year still on earth, when there's rabbits and dogs to out-breed them?

The first reason is that, according to the theory of evolution, there has not been as many generations of humans and their ancestors as there have been of rabbits and their ancestors. The many generations of rabbits and their ancestors has resulted in the amazing reproductive capabilities of the species over time.

The second is that it is not possible for humans to reproduce that quickly, because they are too complicated.