MattyG

The system you're describing is woefully vague. What are the dominant genes that respond to the recessive? Are you describing only one particular gene, or just the total gene pool? Are we to understand that these are negative effects that significantly affect the ability to survive and breed? Do the positive genes significantly increase the ability to survive and breed? A single trait does not have two different recessive genes that code for something. One possible gene will be dominant and one will be recessive (clearly I'm simplifying this to a simple two-gene trait for the purpose of the argument). Let's try a thought experiment in a standard society where excessive inbreeding does not occur. We will look at a negative gene that causes infant mortality, and a positive gene that prevents infant mortality. These are the possibilities. Dom= good, Rec=bad People will survive if they have even one Dom gene, but die if they have two Rec genes. Since anyone with one Dom and one Rec will survive and reproduce without knowing they have the Rec gene, the Rec gene will survive in the population. Inbreeding, working how it works, will cause instances of the Rec gene to increase, causing more children who will die from the defect. Dom=bad, Rec=good People will survive if they have two Rec genes, but will die if they have even one Dom. Anyone with the Dom gene will die, preventing them from surviving and breeding. Therefore, the population will quickly have only the Rec gene. Incest is unnecessary to increase instances of the Rec gene since natural selection has already selected against the negative Dom gene. As demonstrated through the thought experiment, inbreeding is unnecessary to promote the prevalence of positive recessive genes. Natural selection already does that. Additionally, incest can only serve to increase negative or inconsequential recessive genes. That's as simple an explanation of human genetics as I can give. Addition: Just realized I could add an example like Sickle Cell Anemia where a DomRec will prevent future disease So now, Dom=good, Rec=bad, DomRec=best People will survive if they have even one Dom gene, but they die if they have two Rec genes. However, people with both a Dom gene and a Rec gene will live and breed longer than someone with two Doms, because they have an added immunity to some disease (we'll just say influenza). You have a similar situation as "Dom=bad, Rec=good," except the Rec gene will be more pervasive in society since it does, occasionally, provide a benefit. In this case, inbreeding will lead to more people with two Dom genes, or two Rec genes. This is bad for society since it minimizes the maximum number of healthy people. Ideally, if you are DomRec, you want to breed with a DomDom, because, statistically, 0% of your children will suffer infant mortality, and 50% will be resistant to influenza. Now I know what you're thinking. "Now they have 50% of their children DomDom, and 50% DomRec. Clearly those children should reproduce in order to maximize the next generation's gene-pool. However, in this scenario we're assuming that there's no way to tell who has what genes. You could easily pair up DomRec with DomRec, and then a quarter of their children would die. A gene like this is very unfortunate, which is why Sickle Cell Anemia is such a problem. However, inbreeding is not the solution. The best solution is for carriers of the Rec gene to outbreed as much as possible in order to avoid other carriers, while still possibly spreading the flu resistance. And yes, if they're carrier's, the best place to find other carriers is in their own family.

Yeah, still not sure where he got that from, seeing how we've all been very anti parent-child incest, but I suppose you can't argue with crazy.

Very true. On our forum we gave the explanation that most of us see myth as being symbolic, rather than literal and, therefore, depictions of incest are meant to be poetic rather than pro-incest. Additionally, we acknowledge that whatever the gods are, they are not biological organisms, and not susceptible to negative recessive traits.

If that's so, why were you on our forum? Also: "If I understand correctly, inbreeding would slow or stop the proliferation of recessive defects." Did you actually read the comments on this forum? Because no one here's said anything like that. At all. They've said the opposite.

So yeah, this guy decided to argue with the moderators when they called him out for breaking several of the forum's rules, so they banned him. Now he's just whining to whoever will listen I guess. As a member of the pagan community, I hope no one is taking him seriously. To anyone interested, here's the original thread he posted to. http://www.ecauldron.com/forum/showthread.php?4567-Incest-Question

Yeah, no one on the Pagan forum is quite sure what he wants either, or why he's asking us non-scientists about it. I do think it's a little unfair to say that the genetics are completely irrelevant. Humanity as a species thrives when we have a varied and diverse gene pool. That's most likely why we evolved things like the Westermark effect. And like you said, show animal breeding is a perfect example of why incest really isn't a good idea. Personally, I believe the ethical implications come from the fact that 1) You're exposing your child to the increased risk of negative, recessive traits, and 2) You're decreasing the diversity of the human genome. Just a personal belief though. Personally, I don't think I would legislate against two related adults choosing to be incestuous, but I certainly would place societal pressure on them to avoid that behavior. Especially if it was being done to create some kind of master-race. That always works out so well.

I would like to clarify eyesOpened's argument. I'm on the other forum to which he posted this question. He posted the question to The Cauldron: A Pagan Forum, asking us "So, what are the Pagan beliefs and practices with respect to incest?" If this post was not meant to deal with ethics, I can't imagine why he would be posting it to a pagan religious forum. The consensus of the forum was that we are opposed to incest as it frequently causes negative, recessive traits to become manifest. He argued against us (using Wikipedia as his only source), saying that there's no proof that recessive traits couldn't be positive. He continuously asked us to provide proof that there were no recessive genes that manifest positively with two copies, because he doesn't understand how burden of proof works, or how it's relevant to the conversation. Additionally, when asked why he was asking us, a group of pagans, about this primarily scientific phenomenon, he said he wanted an opinion from people who "might be less terrorized and brainwashed by the Bible," as if Christianity is the only plausible reason why someone would be against incest. Additionally, he said that he was "intrigued by the idea of using incest as a means to creating an enhanced sub-species with reproductive advantages." So that's the context of this discussion.