MattyG

its a society, where each individual is generally aiming to kill the one next to them(humans are very violent, or at least the males are)

Where the hell did you get that idea from? One quick scan of the Wikipedia page for Crime in the United States shows that violent crime rates haven't been above 800/100,000 in the time between 1960 and 2010. http://en.wikipedia....e_United_States That's less than .8% of Americans committing violent crimes. And as to warfare, from what I understand less than 1% of the US population serves in the military, and saying that they're just "aiming to kill the one next to them," is incredibly ignorant and disrespectful.

And as to your statement about males being the violent ones, the CDC claims that half of all domestic violence is committed by women. http://www.eworldwir...ssrelease/17670

Please do some research before broadcasting your stereotypes and prejudices.

Also, this has been bothering me:

dose: n. a quantity of medicine prescribed to be taken at one time.

does: v. a 3rd person singular present indicative of do.

Found this video today. Thought it might be helpful.

As to the article you just posted, it is an analysis of hybrid plants, as in one plant being bred with a different species of plant. No one is arguing that it is beneficial to breed with separate species. The article is not comparing plants that are inbred to plants that breed outside of their direct lineage. It's also important to note that, while many plants have the ability to reproduce asexually, producing exact clones (which is more or less what inbreeding attempts to do), the vast majority have also developed methods of sexual reproduction in order to create greater genetic diversity and avoid mass inbreeding.

I've actually just read that paper more carefully. That Mendel's original study that determined that traits are either Dominant or Recessive. At no point did he look at the effects of inbreeding or make comments on the value of the traits from a survival standpoint. He looked at

• Color and smoothness of the seeds (grey and round or white and wrinkled)
• Color of the cotyledons (yellow or green)
• Color of the flowers (white or violet)
• Shape of the pods (full or constricted)
• Color of unripe pods (yellow or green)
• Position of flowers and pods on the stems
• Height of the plants (short or tall)

That's all. You'll notice that none of these traits are particularly detrimental to the plants' survival. Once again, high school level material. If you're going to post articles in an attempt to prove your point, at least make sure you know what they're about.

The point that I realized that you have absolutely no idea what you're talking about:

it is also almost exclusively done chemically in nature (pheromones, they don't work on humans any more)

Look, I have nothing against you. For all I know, you actually are some kind of 10th level Jedi Zen-master who sees through the petty illusions that bind us lesser mortals. If so, congratulations. However, it's impossible for me to argue about genetics against someone who bases their arguments on personal feeling and intuition. I wish you the best of luck in your future endeavors, and would highly recommend that you do some research into pansexuality, seeing as that seems to be the way you identify yourself. As for me, I'm done with this conversation.

that the interesting thing, i don't imagine A is actually B, i decide to like A for being A (or at least a flavour of A) i can't stand stupid manly men, they irritate me (but i dislike the stupidity, not the man)

you see you may not like beets on their own but have you tried the various recipes that use beets?

im sure you have never tried borscht it tastes nothing like beets...

The borscht analogy is awful. Maybe if a male has a sex change operation so they no longer resemble a male, I might be attracted to them, but anything that "tastes" male will be repulsive.

IS BEING STRAIGHT GENETIC!!!(ie the STRAIGHT gene)

(did you expect me to say gay? how silly of you you know me better then that)

(ignore the fact that genes are actually super-coiled and about as far from straight as you can possibly be)

 

the previous statement will blind you if you stare at it too long !!beware!!

Is that really necessary?

also isn't picking up a fetish in a way proof that the gene for sexual attraction to X gender isn't actually a gene for sexual attraction to X gender but more likely just a gene for sexual attraction(non specific), and mutated copies can give you a broader or less specific attraction, or limit your attraction to more specific items, or make you unable to be attracted to other things when a certain trigger is initiated.

 

You are limiting the gay gene to making people gay, genes aren't like that, they usually serve 10 different functions, influence 100 processes, and moderate another 500 linked processes

Bolding mine. That's exactly what I'm saying! Different genetic combinations affect the range of things you're attracted to. That's what all the science since Kinsey has indicated. Most of the population is skewed towards a hetero-sexual bias (as would make sense from an evolutionary stand point) with a range through bi-sexual, to homo-sexual, to pan or omni-sexual. Some people are more influenced by different factors, ranging from physical to personal to mental, but to say that gender isn't an actual factor for anyone is ridiculous. From a purely reproductive standpoint, it wouldn't make sense for gender to play no role for anyone in the matter of attraction. However, there is definitely a range that you can fall in.

Also, I wouldn't say that you pick a fetish, but a fetish picks you through exposure and possibly some previous, psychological experience. No one just sat down one day and decided that they wanted to start getting erections from being pooped on. There was something beforehand that made them curious about the experience, and then when they tried it they found it satisfying.

I never said that there was a single gene that makes someone either gay or straight. There are most likely a number of genes that help influence sexual preference, as well as a number of environmental factors (like the amount of testosterone that you're exposed to in the womb) that come into play. These things have been studied and high correlations have been found. I argue against attraction being a purely rational decision. You have things that you find pleasurable, and things that repulse you. Over time you might discover new things, or different variations, or your taste may change through some factors. But if you could just choose to like something independent of your experiences, well everyone would just decide that doing their taxes should be an orgasmic experience.

i get a sexual response to whatever i find attractive,

also things that i can pervert for my own pleasure,

the idea of pleasure or the prospect of it are also quite useful for this

Dude, that's not special. Anyone can get aroused if they think of something they find arousing, and anyone can pick up additional fetishes along their life. That's normal.

It's not about choosing to get aroused, it's about what you find arousing. A homo-sexual guy can probably have sex with a woman if he chooses to, but if he has to imagine her as a dude to do it, that doesn't make him straight.

It's like food preferences. I personally find beets repulsive. Yeah, maybe I can stomach beets, but no amount of mental willpower is going to change the flavor. There might be someone else who is able to eat absolutely any food under the sun and obtain pleasure for it, but that doesn't mean he chooses to like the flavor of beets. He just does. From what you're indicating, you're most likely pan-sexual (or omni-sexual, I can never remember which means which). That is a completely valid sexual identity. However, that doesn't make it a choice. Perhaps you've internalized it as a choice because that what makes sense to you, but the scientific evidence indicates that it's a result of genetic pre-disposition combined with uncontrollable environmental factors.

you know this how?

saying you cant help it is rather silly, you can say you don’t want to

saying you cant help it means its a compulsion

i don’t know about you but ive never felt compelled to ba attracted to anyone

ive been attracted to their minds, their bodies, personality, once even their confidence in them selves(ie they were really cocky)

it may be because i am bi, or it may be the cause of me being bi, but there is allays a reason why i am attracted to someone

 

now i may be wrong, ive read alot, talked to people, and have accumulated numerous experiences

and based on all these experiences, i would say attraction is mental

you respond to a person because you are attracted to a person because you like them, not their gender

otherwise you would have an erection in response to any vaguely female shaped object in existence even if you caught a small glimpse of it

Having a broad range of features that you find attractive is not the same as choosing who you find attractive. And no one was saying that physical appearance is the only single factor that determines attraction, but for most people it is a big part. Could you meet an ugly, stupid, hateful person and just make the concious decision to be attracted to them? My guess is no. You may personally have a very broad range of traits that are attractive to you, but I don't believe that you just sat down one day and decided what those would be. It's not a decision, it's a combination of your genetic makeup and whatever environmental factors play into it.

Edit: Additionally, no one said that there wasn't a "reason" for people being attracted to someone, nor that physical attractiveness is the sole reason. Just that you don't get to choose the reasons you're attracted to someone. And for both the hetero-sexual and homo-sexual community, gender is a big reason. I know a guy who's only attracted to red-heads. There are almost definately environmental factors that shape what you find attractive alongside genetics, but it's not just a rational decision.

I would like to ask you, if you believe that being attracted to someone of the same gender is a choice, why would anyone choose to do that in a society where they'll face abuse because of it? There's a large number of homo-sexuals who have been led to believe that it's a sin, and they feel awful about it. So why, in your opinion, do they not just choose to not be attracted to the same gender?

to answer number 1...

i offer you 2 plates of food, in one plate is the tastiest steak you have ever seen (but you are a vegetarian, or at least trying to be one because your parents are), in the other plate, a salad, not the best salad ever made... admittedly its wilted and limp, and there a dead fly in it.

to make things more interesting you have just come out of a starvation diet, consisting of your fine leather shoes as your primary food source

which plate would you pick

The debate isn't about whether or not genetics makes you have sex with the same gender. The debate is about whether genetics makes you attracted to the same gender. No one is arguing that a guy who's attracted to men can't or won't choose to have sex with women. Just that he can't choose to be attracted to them. Your thought experiment corroborates this, seeing as even if this starving dude chooses the salad, he actually wants the steak. He's genetically predisposed to carnivorous behavior. He can't help it.

Pagan here, wanting to jump in with my two cents

As we head into the future, will religion ever lose it's grip amongst the people?

I honestly believe that religious fundamentalism might lose its grip in the future, but it's important to distinguish between "religion" and "fundamentalism." IMHO, you don't have to believe myths as literal fact in order to be religious. I personally follow a nature-worshiping religion, so I believe an understanding of science in the natural world to be an important part of that. Historically, some of the first people to look to the stars for answers were considered priests, while now they're considered astronomers. It's not about religion dying, but evolving.

What are your thoughts about this?

I would personally define religion as the attempt to find patterns that define the world we live in, where myths serve as a way for us to connect with the patterns as human beings. For example, the story of Persephone explains a variety of things from the natural order of the seasons to how, as people, we cope with loss and death. Additionally, religion provides us models which we aspire to emulate. Spartans tried to emulate the war-god Ares, while Athenians tried to emulate Athena. Is that really much different than Nazi Germans committing themselves to the war-machine, or the American Revolutionaries fighting for Democracy and Republics. And, ideally, Christians would be trying to live up to the model of Christ's forgiveness, love, and self-sacrifice, even if many don't. IMHO, as long as people try to find order in the universe, and try to conform themselves to ideals, there will be religion. The only real difference is whether you choose to anthropomorphize those patterns and ideals.

And is the Bible guidance for humanity?

If the Bible helps explain your place in the universe, then feel free to follow it. Just don't expect it to apply to everyone else as well. The Norse had to follow warrior-gods because they lived in a particular time and place that made raiding necessary to sustain their population. Smiths would worship Vulvan because they needed to strive for perfection in smithing to make a living. Hunter-gather civilizations will tend to deify the animals and natural surroundings that they encounter and rely on. I think there is no Truth that will apply to every person in every place and every situation. Just a bunch of personal truths.

Would the world be a better place if we were all evangelized?

No, see above

Does anything else teach better ethics than religion?

This, I can't say. I wasn't around in early human development to tell to what degree our idea of ethics and altruism is influenced by biological evolution, and what is influenced by the developments of religion and civilization. And the question still remains, what makes good ethics? In our modern world, we would frown on warrior societies and raiders. However, as I pointed out in my description of the Norse, their society would not survive if they didn't take up raiding. They lived far in the frozen North where agriculture was very difficult. From a pure Darwinian perspective, it was better for them to commit violence against their fellow man, rather then let their wives and children starve. However, if you look at the earliest Christians, they followed Christ and Paul's teachings and avoided open rebellion against Rome, and they survived and thrived, while Jewish Zealots openly rebelled and were banished from their home and scattered across the globe. Christian ethics provided them the attitude to survive, even if submitting to an oppressive government is not ideal in every case. So yeah, I can't really quantify what makes "better ethics," or what teaches them, but I do think that, to a certain extent, it varies from situation to situation.

Hope that helps

And a number of scholarly articles have been posted that indicate evidence of inbreeding leading to higher proportions of helpful and positive recessive genes in the inbred population; and here's an article showing that outbreeding leads to higher proportions of harmful and negative recessive genes in the outbred population: http://www.mendelweb.org/Mendel.html.

There was one article posted relating to cousin-cousin inbreeding in Iceland leading to slightly more fertile relationships, but actually reading the article from start to finish reveals that they are unable "to offer a concrete biological explanation for these findings," and acknowledges that "What gene experts do know is that nookie between closely related people, such as first or second cousins, increases the chances of passing down a recessive gene for a detrimental condition to their offspring." When OP was claiming that this article claimed that outbreeding causes infertility, he was clearly misunderstanding the findings of this research. Clearly, non-inbreeding couples having over three children on average in not infertility. Infertility would be having zero children on average. And the studies don't necessarily indicate that the couples had less ability to have offspring. The article noted that there was a possibility that the non inbreeding couples were just having less sex than the inbreeding couples. And, I'm no expert and I don't know the sample size they were looking at, but I wouldn't think that inbreeding couples have less than one more child than non-inbreeding couples is that significant. Also, one could easily argue that increased fertility is not necessarily a desirable trait in our modern, overpopulated world. Aside from that article, no one else has posted evidence of the inbreeding leading to higher proportions of helpful and positive recessive genes in the inbred population.

As to the article you just posted, it is an analysis of hybrid plants, as in one plant being bred with a different species of plant. No one is arguing that it is beneficial to breed with separate species. The article is not comparing plants that are inbred to plants that breed outside of their direct lineage. It's also important to note that, while many plants have the ability to reproduce asexually, producing exact clones (which is more or less what inbreeding attempts to do), the vast majority have also developed methods of sexual reproduction in order to create greater genetic diversity and avoid mass inbreeding.

This thread should be renamed "inflammatory and provocative hand-waiving to detract, just a version of the red-herring fallacy".

 

 

 

 

 

Looks like it's never been published.

Hi offended. Nice to see you posting in this thread. Well, there is probably no science published to indicate that "Most of the odd things tied to recessive genes in humans are defects," but no one on this thread, save OP, has posted a claim to that effect. However, a number of scholarly articles have been posted that indicate evidence of inbreeding leading to higher proportions of harmful and negative recessive genes in the inbred population. If you'd like, you should feel free to discuss the actual topic of the effects of human inbreeding, but I really don't see how renaming the thread is on topic.

Besides susceptibility to diseases, there have also been studies linking inbreeding to mental disorders such as retardation, low intelligence, unipolar and bipolar depression, and schizophrenia.

 

http://www.matthewck...lution_2006.pdf (7.4. The effect of inbreeding on mental disorders)

I plan on reading this article later when I have time to make some sense of it. Could you possibly summarize the findings? Is it suggested that these mental disorders (though I don't like to categorize "low intelligence" as a disorder) are essentially recessive traits that manifest more often through inbreeding, or that there are additional factors?

Also, keep in mind that the Greeks were defending a narrow pass. The Persians may have had superior numbers, but it was never all the Persians attacking all the Greeks at once. Lets say that the pass is only wide enough for 20 Greeks to stand shoulder to shoulder. Well, that means that at any given time there can only be around 20 Persians attacking at a time, possibly less if they're not attacking in formation. And as long as the Greeks keep their shields up, it's going to be difficult to break the line. I hope that helps.

It is interesting to note that while homosexual behaviour is known in many species, homophobia has only been recorded in one.

This suggests that the latter behaviour is much more "unnatural" than the former.

I know this is completely late, but I hope you don't mind if I quote you in the future.

So I was wrong to assume that anything you've said in this thread was relevant to the thread's first post.

You were wrong to say that I made the claims in the first post. No one in this thread has made the claim that "Most of the odd things tied to recessive genes in humans are defects," including myself. If you want to argue with me or discredit my claims, do not put claims in my mouth in order to do it. I have made several posts relating to the science and history of inbreeding and its effects on human genetics. If you are going to attempt to discredit me, please at least cite things that I have actually said.

Who said anything against homosexuality, or even against homosexuals who stalk guys from website to website, thread to thread? Stop responding to internal stimuli, and re-read what I actually typed?

I'm sorry, but I think you should take your own advice and re-read what I actually typed. I discussed the historical Socrates and how there was no evidence that he practiced homosexuality, despite your claims that he did "gay stuff." I then discussed the topic of this thread, describing how slanderous accusations of homosexuality in order to insult, offend, or discredit an opponent are a trademark of trolling, and we would in fact be inclined to label Socrates as such, had he stooped to such immature methods of discourse.

Then out of personal interest I voiced a question to the moderators about forum rules. I never asserted that anyone on this thread or anywhere else had "said anything against homosexuality." Except the trolls, among whom we do not find Socrates.

The proposition quoted in the first post in this thread, to start with.

Firstly, your assertion that my claims were "unsupported" was a response to a specific comment in which I made several claims about the biology of inbreeding. Not to "the first post in this thread." Which of those specific claims are unfounded?

Secondly, the first post in this thread was your own. While I would agree that most of your claims are unfounded or highly misconstrued, I find it unlikely that you're referring to your own claims. Therefore, I can only assume that you meant my first post to the forum, which was, in fact about the religious debate that brought you to this forum.

It's debatable whether or not that specific claim was unfounded since a link to the previous forum was posted for anyone to see, but I will agree that it was severely off topic. I've made my apologies to the moderators of this community since their warning was posted, and have since attempted to keep my posts in this thread to specifically scientific matters.

In conclusion, if you believe that any of my claims relating specifically to the science and/or history of inbreeding from a genetic standpoint are unsupported, please cite specific claims, and please try to keep the discussion on topic.

Edit: Sorry, you've edited your quote since I posted this. As to "Most of the odd things tied to recessive genes in humans are defects," I've never made that claim. You're the only one in this thread who's ever stated that. I've only said that recessive traits with a positive influence are going to tend to become the norm in a human population, because the negative dominant traits are going to be selected against naturally. I've also stated that the kinds of recessive traits that are likely to become manifest through inbreeding are going to be either negative or inconsequential, since those are the kind that are going to hide in a population's gene pool without presenting themselves as often (examples, the red-head gene as inconsequential or the genes for Cystic fibrosis as a negative). Please avoid putting words in my mouth in the future.

Socrates might have done some gay stuff, but nothing as gay as following me from website to website, thread to thread, to lavish attention on me.

Actually, there's no actual evidence to assert that Socrates was at all homosexual. In fact, he was married and had children. However, on the topic of him being a troll or not, one would assume that if he were to go around peppering his discussions with homophobic remarks and accusations, he would, in fact, be classified as a troll.

Question to the moderators: Are homophobic remarks and accusations allowed on this forum?

Unsupported opinions are a dime a dozen.

Which of my "opinions" are unsupported? The ones I've supported with history? The ones I've supported with logical thought experiments requiring no more than a high school level of understanding of biology? The ones supported by genetic and social norms? The ones supported by scientific research (I know you love Wikipedia, so http://en.wikipedia.org/wiki/Pedigree_collapse http://en.wikipedia.org/wiki/Consanguinity as well as 48,800 scholarly articles found through a simple Google search http://scholar.google.com/scholar?q=Effects+of+human+inbreeding&hl=en&as_sdt=0&as_vis=1&oi=scholart&sa=X&ei=oCVQUIH6PO32igKSzYH4CQ&ved=0CBwQgQMwAA feel free to browse them at your leisure)?

So please let me know which claims I've made that lack support.

So much is clear to you, just like the guys who got angry at Socrates. I won't respond to your statements about me, since they are off topic, and on this "General Philosophy" forum I do not care about the discussion on the "Genetics" forum. Why don't you forget about the discussion on that other forum altogether? Any mention of it will be seen as off-topic in this thread. Any mention of me personally will also be seen as off topic in this thread. If you wish to discuss me, why not do so in another thread? This thread is not a place to finish a fight from somewhere else.

I don't think Socrates was a troll.

 

But if you ever did manage to classify him as a troll you would also have to consider him as Plato's sock puppet.

It doesn't look like OP actually wants to know whether or not Socrates would be a troll. He wants people to confirm his opinion that he is like Socrates.

But yeah, the Plato's sock puppet analogy is perfect for any conversation actually about Socrates. It's important to understand that the only Socrates we really know about is essentially just a character.

You've ignored the other half of this analogy.

Also, ignoring the fact that a great number of plants and animals do suffer from frequent inbreeding. For example, the potatoes of the Irish potato famine, or purebred dogs that frequently display hip problems and the like.

Now we have to go back and correct all the claims that inbreeding "causes defects", since it doesn't 100% of the time.

No one has claimed that 100% of outbreeding results in beneficial traits, or that 100% of inbreeding results in negative traits. Inbreeding has a much higher likelihood of producing negative traits, with little to no higher probability of producing positive traits.

Outbreeding has been the norm for most animals for a good reason. Inbred populations have less variability in their gene pool. They are not properly equipped to deal with a wide variety of environmental factors. If inbreeding produced more beneficial traits in a species, it would be far more common. You're not just arguing against opinions, you're arguing against scientific and historical facts. Life on Earth, animal life in particular, has evolved a method of reproduction designed specifically to increase the variety of genetic diversity. The Westermark effect helps inspire us to have children that are genetically different from ourselves. It's the best way for us to survive as a species, and the best way to keep individuals alive and healthy.

You refer to the much higher percentage of the population who have sickle cell anaemia in areas of Africa susceptible to 'sleeping sickness' (Human African trypanosomiasis) caused by the Tsetse Fly. At university (in the 90's) this was described as a local example of continuing human evolution (survival of the fittest). Inbreeding between people with this disease would serve no purpose and give no extra benefit so it is not a good example.

Sorry, but I'm not sure I get what you're saying. I wasn't saying that inbreeding between people with the disease would help. I'm making an argument against inbreeding. If you're a carrier of the Sickle Cell gene, it's best for you to outbreed so you avoid giving your child another sickle cell gene from a closely related person.

I can't speak for them, but some of the propenents of forced-outbreeding (i.e., eugenics) may have a hidden agenda of trying to garner mainstream acceptance of their animal-f-cking ways. You know, "hey the reason I like f-cking animals (all animals, not just mammals) is to maximize the population's gene variability, uber-population, so we can avoid extinction."

Eugenics: eu·gen·ics   [yoo-jen-iks] noun ( used with a singular verb )

the study of or belief in the possibility of improving the qualities of the human species or a human population, especially by such means as discouraging reproduction by persons having genetic defects or presumed to have inheritable undesirable traits (negative eugenics) or encouraging reproduction by persons presumed to have inheritable desirable traits (positive eugenics).

No where does it say that eugenics focuses on either outbreeding, or animal-fucking as you claim. I know it's much easier to make an argument when you change the definitions of words, but I think bringing in animal-fucking was probably going too far. Eugenics generally focuses on inbreeding, whether within families or specific ethnic groups, from the belief that that specific group contains the best genes, while other groups should not be allowed to breed. Also, I'm concerned that you think that human beings can reproduce with animals. My university degree may not make me an expert, but I really think you should have a conversation with your local high-school biology teacher before trying to argue any further.

It used to be said that the idea of a beneficial recessive trait was a joke, but sometimes people just talk instead of thinking.

No one ever said that. They've just said that beneficial recessive traits will tend to become the norm, as negative dominant traits are weeded out more quickly.

Sometimes, and sometimes narrowing the gene pool leaves the population more able to deal with "disasters".

No, not really. Only the family of inbred hicks that just happens to have the one specific gene to deal with the one specific disaster. And the next catastrophe is going to wipe them the fuck out.

Touting a university degree and calling your opponents Hitler is what it is, but it's not the same as supporting your assertions with evidence, and around here, people are said to be required to support their assertions with evidence.

I don't ever remember using the word "Hitler," but I do remember listing various historical examples of inbreeding gone wrong, as well as some basic, high-school level thought experiments with basic biology, so there's that. And once again, my university degree by no means makes me an expert, but it's still better than not understanding elementary biology concepts.

I am listening to your answers and learning, but if he came and asked a direct question, and he insisted he was being earnest, what procedure could we use to determine whether he was in fact being earnest, or whether he really "had no intention of" "listening to the answers" and "learning anything from them"?

 

 

How do you know what he was really trying to do?

Well, if he chose specifically to ignore evidence, asked people to prove the non-existence of something, edited his evidence in a manner to support his claims, stated that people had said the opposite of what they had said, constantly misunderstoods the context of people's statements (either intentionally or not), or stated that he failed to see the relevance of entirely relevant comments, then chances are he was a troll. Additionally, Socrates would generally be asking people to question ethical questions, not questions of science. Subjective beliefs as opposed to objective beliefs. If one attempts to dispute someone's scientific claims without having evidence of their own, then they are absolutely a troll.

I see your point: "its an argument from the point of population genetics, not focused on individuals or specific traits". From your explanation, does it follows that a population lacking variability would have "a very high chance" of universal immunity from "an event", while a population with variability would have a lower chance of universal immunity?

Inbreeding causes a "very high chance" of universal susceptibility to diseases. This is exactly what happened during the Irish potato famine. As I learned in my university biology class, nearly all the potato plants in Ireland were descended from a single specimen from the Americas. The plants were nearly genetically identical thanks to inbreeding. Then when the potato blight (Phytophthora infestans) hit Ireland, none of them had resistance because they lacked the genes that provided resistance, and could never gain them because they only inbred. This caused an enormous ecological disaster, not only killing the potatoes, but the people that depended on them. The idea of "universal immunity" is a joke. A species survives best when they have the greatest possible number of genes. Inbreeding narrows the gene pool significantly, leaving the population unable to deal with unforeseen disasters. Ok, maybe this inbred community will be "universally immune" to one disease, but the lack of variety is going to leave them unprepared for a million other diseases that want to fuck them up.

I don't understand why people feel the need to take natural selection into their own hands and breed some kind of uber-mensch. I think evolution's been doing a pretty good job on it's own. There's no such thing as "perfect genetics." Different genes are beneficial for different purposes. White skin is great for producing vitamin D in polar climates, but gives you cancer in equatorial areas. Increased intelligence is good if you're part of an advanced civilization, but a big brain's a waste if you don't have the caloric intake to support it. Nature has a way of weeding out things that are entirely useless. Have a varied gene pool, and your population can survive anything.

Suppose that we start with a gene pool where half the recessive genes carry defects, and the other half carry enhancements. Suppose also that there are no mutations. The evolution of that system would lead to a state where recessive enhancements would outnumber the recessive defects.

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.