Just to toss a few thoughts into the mix, here is some of the current thinking re a genetic link for same sex attraction. This is a very simplified version of what little is known to date.

Eggs and sperm are 'imprinted' with certain genes enabled and certain others disabled. The key here is that the egg cell gets imprinted with a different set of enabled genes than a sperm and vice versa. The number of 'imprinted' genes is very small, one estimate I saw was that it was less than 50 but more than 20. By far the bulk of the genome is active, but for the small subset of imprinted genes, they can be either on or off depending whether they originated in an ovary or testicle. A good bit of work has been done linking the imprinted genes to homosexual behavior.

For homosexuals, there is a slight pattern of having a particular type mother with more than normal masculine traits. There is some speculation that these women originated from an egg that was imprinted with more masculine traits which they then pass on to their children when their own egg cells are imprinted. What is not yet known is exactly how the imprinting goes awry in the first place.

Zeta, I'm posting this to point out that there is ample evidence of genetic factors in homosexuality. It is an established fact that families with one homosexual member are more likely to have another.

DarJones

DarJones,

I'm open to you citing studies. Please feel free to do so. But, as I said, from what I was told from experts in the field, there are no reputable professional papers claiming strong genetic links to SSA.

One of the most interesting things about this whole issue is the differences of opinions on almost all the issues. I think it was Brian who claimed, earlier in the thread, that being raised by parents with SSA *didn't* tend to lead to the children following; and Brian even provided a few links to reputable sources for those claims. If it could be shown that SSA was genetic and inheritable, then I think there would be very strong reasons for the state NOT to allow, for example, lesbian couples to have access to sperm banks; or to accept sperm from men with those genetic markers. As technology improved, and we were able to change which genes are turned on and off, or which children are born, I suppose SSA could be eradicated, or spread, as society deemed wise.

[QUOTE=Zeta-Flux;135199]If it could be shown that SSA was genetic and inheritable, then I think there would be very strong reasons for the state NOT to allow, for example, lesbian couples to have access to sperm banks; or to accept sperm from men with those genetic markers.[/QUOTE]I find this specific thought particularly chilling. Genetic markers can likely identify all kinds of things including behaviors but I do not find that to be a basis for denial to any kind of procreation including via sperm banks. I suppose certain known markers in a genetic sample should be made available for informed consent but even that is potentially extremely troubling and only to be explored with great difficulty.

[quote=Zeta-Flux;135163]But even ignoring all of this, let us suppose for the sake of argument that humans evolved in a manner so that a small, but sizable, minority of them were attracted to the same-gender. If this is the case, we naturally ask, "Why? What is the evolutionary benefit?"[/quote]There does not [I]have[/I] to be any benefit. There only has to be a lack of enough disadvantage for it to be eliminated through natural selection.

[quote]It might be, for example, having extra people to raise children without producing more of them. It might be something else.[/quote]This was discussed last year in the "Evolution: The Scientific Evidence" thread:

[URL]http://www.mersenneforum.org/showpost.php?p=102879&postcount=236[/URL]

Zeta-Flux,

Why is it that you appeal to professional refereed papers in (scientific) journals to support your position:

[quote=Zeta-Flux;135163]From what I've been told by people who study this issue, there is actually very little evidence (especially in terms of professional refereed papers in journals) that genetics is what causes same-gender attraction.[/quote][quote=Zeta-Flux;135199]I'm open to you citing studies. Please feel free to do so. But, as I said, from what I was told from experts in the field, there are no reputable professional papers claiming strong genetic links to SSA.[/quote]... but refer to God as some ultimate authority:
[quote=Zeta-Flux;135095]My only implication with regards to your specific relationship is that you should not act on your feelings IF God tells you not to. I have beliefs about homosexual acts in general, but I do not judge your specific situation. Your feelings for each other are what they are. I am not judging your specific choices as I am not God.[/quote][quote]But, with regards to some of the acts within your relationship, I believe that they are reserved only for certain circumstances okayed by God[/quote]... even though there is no scientific evidence for the existence of God other than as an idea in human minds?

I asked you, a while back, for scientific evidence of God. You cited none, only referring me to another forum -- on which I found no cited scientific evidence for God, either.

Where are the papers in refereed scientific journals that present evidence for the existence of God outside the thoughts of humans? Isn't such evidence necessary in order for your God-based arguments to have any weight in a discussion where [I]you[/I] request that others present scientific evidence to support their arguments opposing yours?

- - -

(Oh, BTW -- arguments that boil down to "I can't imagine any other explanation for X than that God exists" -- the God of the Gaps theory -- don't count. All they are is evidence for the limitations on some people's imaginations.

That's why Intelligent Design is not science.)

only_human,

Yes, there are chilling aspects, on both sides. On the one side, we could move towards a society like that portrayed in Gattica. One in which people's livelihoods are based upon their genetic "purity." On the other hand, if we have the ability to tell that a certain sperm and egg combination will most certainly result in a horribly painful disease, are you willing to allow that to happen? If there are gene treatments which can remove many of those conditions, are you willing to take accountability for all the suffering of the children born with them by not allowing said treatments? And then there is the issue of what lines to cross. If SSA were something that could be easily changed through some treatment, would it be moral to block it? To encourage it?

As cheesehead intimated, some genetics die off because of lack of reproductive ability and/or desire. But if we start allowing lesbian couples to have access to sperm, and assuming that their children inherit SSA, then in effect we are breeding a new type of human. One that doesn't (at least according to modern society) need males to exist, except as a source of sperm.

These are all implications which, at least in my humble (or not so humble, as the case may be) opinion, science needs to explore and report back on. We should move cautiously. The courts shouldn't be the ones to interpret the science for us.

---------------------------------

cheesehead,

[QUOTE]There does not have to be any benefit. There only has to be a lack of enough disadvantage for it to be eliminated through natural selection.[/QUOTE]True. Thank you for pointing that out.

In the context of my comments, I was trying to give the benefit of the doubt that this, possibly genetic, condition wasn't a non-beneficial aberration from the average human genome.

[QUOTE]This was discussed last year in the "Evolution: The Scientific Evidence" thread: [/QUOTE]Yes, which one reason why I brought it up. :) Thanks for the link.

[QUOTE]Why is it that you appeal to professional refereed papers in (scientific) journals to support your position...[/QUOTE]I can think of three reasons off the top of my head. First, because I value scientific research. This is a scientific question, and I can rightly appeal to such an authority. Secondly, because I believe my [i]audience[/i] also values what scientists say. Thirdly, because sometimes the media (including news agencies) report the sensational, and give a mistaken impression of what actual science says.

[QUOTE]... but refer to God as some ultimate authority[/QUOTE]The fact that I view God as an authority does not diminish the fact that I view other sources as authoritative in their spheres. Further, not everyone views God as an authority, nor agrees with me in what I believe God says, so in communicating with others I try to use sources we both find authoritative.

[QUOTE]I asked you, a while back, for scientific evidence of God. You cited none, only referring me to another forum -- on which I found no cited scientific evidence for God, either.[/QUOTE]I don't remember this exchange. Would you be willing to provide a link so that I can refresh my memory. I would be greatly surprised to see myself referring to another forum in response to such a question!

[QUOTE]Where are the papers in refereed scientific journals that present evidence for the existence of God outside the thoughts of humans?[/QUOTE]This is a question for another thread, and quite off-topic.

[QUOTE]Isn't such evidence necessary in order for your God-based arguments to have any weight in a discussion where you request that others present scientific evidence to support their arguments opposing yours?[/QUOTE]Not at all. Others on this thread, of course, are free to state their opinions; as I have done with respect to my personal beliefs. But they cannot pretend that those opinions are based on scientific evidence alone, without quoting from actual scientific studies.

In other words, I think you are reading a little too deeply into my requests. People can believe what they want. But if someone makes a claim about what science says, I like to see the source of said claim. [So, for example, I've never made the claim that modern scientific papers have provided evidence that God exists. To ask me to provide such scientific papers makes no sense. But others HAVE claimed such studies with regards to a genetic link to SSA. To ask them for those papers makes absolute sense.]

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P.S. I was listening to an interesting program (I think it was on NPR) about science and God. The person they were interviewing talked about the "God of the gaps" idea, and how it was theologically a blunder. I tend to agree with this assessment. If there is a God (and I believe there is) then He is the God of the universe, not a fix-it man.

Zeta-Flux,

Leaving off the last part ("... even though there is no scientific evidence for the existence of God other than as an idea in human minds?") in your quotation of the first sentence of my preceding post obscures my point, which was that you were employing a double standard. Neither of the parts you quoted was intended to stand alone.

Therefore, my sentence, "Where are the papers in refereed scientific journals that present evidence for the existence of God outside the thoughts of humans?" is indeed [U]on-topic[/U] because it asks you to provide the same level of evidence that you have already asked others to provide.

[quote=Zeta-Flux]In other words, I think you are reading a little too deeply into my requests.[/quote]No, I'm asking you to apply the same standard to your own argument that you ask others to observe. You imply that opinions opposing yours are inadequate unless backed up by scientific evidence, so either your [I]opinion[/I] needs to have the same backing, or you should admit that this direction of your response to the opposing opinions is not fair.

[quote]But they cannot pretend that those opinions are based on scientific evidence alone, without quoting from actual scientific studies.[/quote]You seem to be pretending that your opinions [I]which have no scientific backing at all[/I] are on a level superior to opinions which have some shred of scientific backing. Sure, you can call for citings to support the claims of the others -- but that's just what I'm doing, too, so it is indeed on-topic. Single standard, please.

cheesehead,

[QUOTE]Leaving off the last part in your quotation of my sentence ("... even though there is no scientific evidence for the existence of God other than as an idea in human minds?") obscures my point which was that you were employing a double standard. Neither of the parts you quoted was intended to stand alone.[/QUOTE]

I apologize. Your sentence was broken into three parts, separated by multiple quotations. I did not mean to change the meaning of your sentence. At least I myself understood quite clearly that you perceived a double-standard. I hope that I resolved your concerns on that matter in my post, by pointing out that I have not made the claim that [b]scientists[/b] (in their roles as scientists) have provided evidence of God, and that I only request scientific studies when others have claimed that scientists have provided evidence for said claims. Do you still perceive a double-standard in that?

Best,
Zeta-Flux

P.S. You just edited your response to state [QUOTE] You imply that opinions opposing yours are inadequate unless backed up by scientific evidnce, so either your opinion needs to have the same backing, or you should admit that this line of your response to the opposing opinions is not fair.[/QUOTE] I have not meant to imply this. I have only meant to imply that they are not scientifically backed if they cannot provide said scientific backing. If a poster was only trying to express his/her opinion on the matter, and I mistakenly assumed they were claiming scientific backing, I apologize for that.

Zeta-Flux,

I've made several changes to my previous post.

Perhaps you should erase your response and start over answering what is there now.

... and I can see that I should have made that interrupted sentence of mine clearer.

Dear cheesehead,

I think that, apart from a comma, the quotations in my post are word for word, so the response can stand. I must admit that I am surprised that I haven't resolved your concern that I am employing a double standard. I have only ever meant to call for scientific studies when I believed that the poster believed that his or her claims were backed up by science.

You state: [QUOTE]You seem to be pretending that your opinions which have no scientific backing at all are on a level superior to opinions which have some shred of scientific backing.[/QUOTE]This is a serious misreading of my intent, character, and words. If you still believe I am employing a double standard, it seems to me that this is a belief based upon a faulty reading of my intent, rather than a logical contradiction that I could explore with you. If you still believe my intent to be what you said above, you could give a few specific instances where you percieve arrogance, and I can try to clarify, although this would likely detract from the thread.

Best,
Zeta-Flux

[QUOTE=Zeta-Flux;135240]only_human,

Yes, there are chilling aspects, on both sides. On the one side, we could move towards a society like that portrayed in Gattica. One in which people's livelihoods are based upon their genetic "purity." On the other hand, if we have the ability to tell that a certain sperm and egg combination will most certainly result in a horribly painful disease, are you willing to allow that to happen? [/QUOTE]YES. e.g.: Sickle Cell Anemia

Evolution does not know what evolution needs. Evolution is under active direction all the time when we make choices based on beauty, strength, size, etcetera but the overriding importance of a diverse gene pool is sine qua non. I don't see the situation returning anytime soon but it has been recently suggested that the human population was reduced to as little as 2,000 individuals as recently as 70,000 years ago.

People always worry about the consequences of the dominance of some faction or the diminishment of another. Evolution is a continuing process of optimizations and it is of primary importance to allow diverse choices.

Imagine the optimization to be a billy goat looking for the highest piece of mountaintop to stand upon. It is only through going very far downhill and much astray that the goat would be able to reach a much taller mountain than the one upon which it originally stood.

So deciding not to ever let the goat go downhill defeats the purpose and it is best not to get into the hideous process of adhering to any particular belief of downhill. Added: Also best to not get too specific into the nature of the goat itself; it could be singular or many kinds of groups. (Gratuitous final addition follows -- I just couldn't resist) For that matter, best not to be too specific about the nature of the mountain either (or the number of turtles necessary to support it).