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Author | Topic: Homosexuality and Natural Selection. | |||||||||||||||||||
Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
I come across Gay people that tell me that Evolution invented gay people to cure over population. I tell them this is not how the process of Natural selection works. It depends how they say it and what they mean when they say it. I might say that evolution invented certain cell structures that fox antibiotics to cure 'antibiotic death' in bacteria. In a way I'm right, but my language is informal. It has been observed that some organisms limit how many offspring they have in overpopulated conditions. This is generally done by limiting the size of a litter or the number of eggs laid etc. This can be explained quite easily using evolution mechanisms. The idea that homosexuality is an evolutionary response to overpopulation is on the face of it feasable, but I'm not convinced. Why not render the male or female infertile? It's quicker and more effective for sure. My money is on the situation being a little more complicated than all that.
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Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
I guess we're kind of hardwired to find purpose in things, so that we see it even if none exists. For some people, the instinct is too strong to overcome. One could ask them to read some Dawkins - since he spends a lot of time trying to break down this appearance of purpose. I doubt that will happen, if you think you are important in some noble evolution delusion there's not much one can do.
Seems you are doing as well as possible to put it to them, but they sound like they have come to their conclusion and will not be shaken. Good luck.
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Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
Absolutely. But what if it was all, and not some? If all members of a population were not reproductive, there would be no reproduction. Naturally, this is not an evolutionarily stable strategy. In humans, homosexuality ratios might be an ESS, just like insect colonies find their own ESS for non-reproductive members. As well as homosexuals there are probably other members who are genetically inclined towards celibacy. I reckon there might even be an ESS for those memetically inclined towards homosexuality or celibacy or other non-reproductive tendencies (such as members of VHEMT).
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Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
The Fitist is the Heterosexual as this life form is MORE likely to pass on it's genes into the future in the form of offspring. A celibate person ( lifeform ) is also weaker than a sexualy active life form. Oversimplifying things slightly. Consider this scenario A pair of identical twins who are genetically disposed towards childcare but not child bearing. One of them has a child and both twins dedicate themselves to raising and looking after the child. The childless twin genetically gains from the episode since the child is genetically as close as the twins own child would have been any way (50% of the genes). Meanwhile another pair of twins exists. This time they have mutltiple children but they don't look after their own children and spend their time trying to kill or harm the children of the other. This time both lose despite siring many children - since the children never make it to reproductive age the genes of both twins fail to be passed on and fortunately the infanticidal gene is lost. In our complex social world filled with sickness and overcrowding, caring for a child to ensure its survival might make one more 'fit' than being philoprogenitive.
this type person is less likely to pass on its genes as most homosexuals are. In the rules of Natural selection that would make me and gays Unfit...I.E. Weaker! Passing on one's genes doesn't mean one has to reproduce. Your siblings share 50% of your genes and your cousins share 12.5% of your genes. It may turn out that a family unit that contains x% of non reproducing members passes on more of its genes - therefore more genes of the non-reproducing members get passed on by not reproducing than would have been passed on had they tried to procreate. That would make them evolutionarily more fit. Edited by Modulous, : No reason given.
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Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
But outside of twins, or direct relatives, your scenario is meaningless to his point. Not really. His point was that the only determinant of fitness was reproduction. I was pointing out that the determinant of fitness was passing on as many genes as possible - directly or indirectly. Sterile insects never reproduce but they are fit because they ensure their genes pass on through their sisters/brothers (in some insects they may even be identical sisters/brothers just for added flavour).
Can't it be agreed that anyone who does not act to reproduce, or is less likely to reproduce, is a "weaker" reproducer from the purely evolutionary standpoint of passing on genes? I'm not sure why that in itself is a contentious claim. My point was that this isn't necessarily the case. It might be the case that high fecundity and no child caring members of a group is the measure of fitness - or it might not. If a person that does not reproduce helps their own genes in other ways, then they might calculate out to be fitter than a dedicated baby maker with a high infant mortality. The contention is that reproduction is not necessary to ensure that your genes are passed on - it is not the be all and the end all.
As families get smaller...an individual's reproductive choice may become more important with respect to "passing on one's genes".
Well, choice is a funny word. But yes - what the optimum strategy for direct reproduction or protection of genes through child caring varies from environment to environment - one would be mad to suggest otherwise. With a small family environment it might turn out that the 'child caring' class increase in size depending on other selection criteria until it reaches a new equilibrium point. Edited by Modulous, : just added a little bit
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Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
I was trying to say that that ASSUMES there are other "family" members to which any are helping. I don't know if there is any correlation between being gay (or celibate) and having more family that have more kids or that have more successful kids (especially helped by the gay person). In fact that seems a bit fanciful. I'm not assuming that gays have philoprogenetive families (though that might make for an interesting study). I'm not coming close to suggesting that. I was simply suggesting that the blanket statement:
quote: and
quote: and so on, are not strictly true. If homosexuality/celibacy/infertility is genetic it might be an evolutionarily stable strategy where a pure hetero- population is not. Reproduction is not the be all and end all of evolutionary fitness.
If you are suggesting the "human family" as a whole, I think we are venturing into a strange area of discussion as it is various characteristics arising within the population which get selected on, and not all characteristics as a whole No, I'm certainly not espousing some kind of group selection concept.
I'm also a little hesitant to be drawing connections between anyone who is not reproducing to the sterile class of animals within an insect colony. The latter clearly do have evolved purposes for the colony, which is not the case for human behavior.
That sounds like an absolute statement there. Remember, the post I was responding to was assuming that the reasons for reduced fecundity were genetically based (as the thread is centred around). If homosexuality has a genetic bias, then there is - in a sense - a sterile class of humans. Its not entirely accurate, but it doesn't need to be since it is about statistics and tendencies which is all we really need to discuss. The ants are working for the colony, but they are not selfless. Each ant is a selfish collection of genes whose sole purpose is to try and make sure as many genes pass on as possible. If homosexuality has a genetic base, then several options for how it maintains its position in the gene pool 1) It is a statitistical result of recombination. The 'gay gene' does not rely on inheratance to propagate, but chance combination of certain alelles in a certain way. 2) A statistical increase in altruism/child caring. If option 1, then homosexuals are less evolutionarily fit and certain alleles may reduce in frequency as they are selected out for finding themselves in gay hosts more than other alleles. If option 2, then what I said. Since we are unable to test our ancient ancestral lineages for correlations between child caring responsibilities in social groups and homosexuality one would be very bold to try and make absolute statements as to the fitness of homosexuality in the grand scheme of things. We can try and work out how fit homosexuality is now, but it is still a very difficult task for obvious reasons.
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Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
But it is on the individual, or single gene line, level which is the point I was making and I think the poster was sort of coming from. Any individual when looked at from an evolutionary standpoint, could be considered "weaker" in comparison to other individuals based on his stated criteria. Well one can make any judgement on weaker/stronger on any criteria one chooses. When talking about genetic causes for homosexuality or altruism or whatever the individual is not the unit of selection, the gene is. Thus if one copy of a gene can sacrifice itself (by not replicating directly) to ensure that another copy of itself definitely does get replicated, then the job is done. Any gene which manages to replicate itself more often than its alleles will spread throughout the population - and it doesn't matter how that replication is acheived.
Looking at colonies this is especially true, but then the drones really are adapted to a purpose which aids the population as a whole. We can see it. Of course this, and the single organism/organ analogy are fair enough, but the central point remains that it is the genes that are protecting themselves and working to replicate themselves using an evolutionarily stable strategy for doing so. Each individual insect is no massive loss then, since the genes 'stored' in that individual are copied a million times throughout the colony.
That's not true if homosexuality is a side effect (perhaps just a potentiality) caused by a gene that produces a totally different effect which allows for its propagation. That's the spirit! The gene for homosexuality can have other ways to help propagate itself meaning that a term such as 'weak' is not necessarily true.
And this also assumes that homosexuals will not procreate, which simply is not supported by any historical data. Nobody is suggesting that homosexuals don't procreate, just that they have a tendency to procreate less which decreases their average fecundity which would appear to reduce their fitness. One homosexual might have a hundred kids, should they choose to and that is easy to see. If you want to argue that homosexuals are equally progenitive, then by all means present your case to the thread...it's not particularly relevant to this little subthread though since that is exactly what we are assuming without shame of admitting it. The point being that any reduction in fecundity could be made up in other areas, such as altruism. Edited by Modulous, : No reason given. Edited by Modulous, : No reason given. Edited by Modulous, : No reason given.
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Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
But as a nitpick, if the gene which results in homosexuality for some offspring is actually used to produce other effects, and indeed gets selected for that reason, I'd hesitate to call it a gene for homosexuality. Well indeed, that goes without saying. It is highly likely that any gene for homosexuality is like other genes in that it has multiple roles. As has been speculated upon here, it could also cause increased altruism or increased fecundity in non homosexual carriers. Calling it the gene for homosexuality would still be perfectly valid since that is what it is, it is also the gene for something else too. Naturally, the whole thing has been simplified massively, it is unlikely that one gene alone is involved - but this level of discussion is not necessary to get the point across.
I think you are both right, but its just a matter of viewpoint. Indeed it is. When talking about reduced fecundity considering the individual as a unit of selection is not necessarily correct though. One cannot simply state that an entity that does not reproduce has a reduced fitness in evolutionary terms. It makes perfect sense in the simplified version of evolution, but not in the real version of it. A sterile insect is not a evolutionarily unfit organism, otherwise sterile insects would be getting selected out by natural selection.
I think it would be generally anecdotal, but same would go for being asked to prove that heteros are more progenitive. It doesn't really matter. The heart of the matter in this subthread is not homosexuality per se, but instead it is about how genes which reduce fecundity could happily survive in a population. If you wish to go down this road in any way, you may want to reply to Message 68 where CDarwin puts forward the position that
quote: Edited by Modulous, : No reason given.
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Modulous Member (Idle past 181 days) Posts: 7801 From: Manchester, UK Joined: |
I saw a news article recently related to my Message 70 and Message 72 and most interestingly - Message 74. I said:
Mod writes: Holmes writes:
I'm not assuming that gays have philoprogenetive families (though that might make for an interesting study).
I don't know if there is any correlation between being gay (or celibate) and having more family that have more kids or that have more successful kids (especially helped by the gay person). In fact that seems a bit fanciful.
homosexuality link to fertility genes quote: So once again, any gay genes in the population may have side effects that allow for their propagation through other means. In this case a male homosexual gene increases a female's fecundity so she has more babies and thus passes on the homosexual gene to some of them too.
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