jp255

I understand that you are arguing for a net benefit. However I don't think your arguments are strong enough to presume a benefit and I don't think we have enough information to make such conclusions. It isn't that I deny the existence of a cost, there is energy and time devoted to homosexual behaviors, it is that I am questioning the significance of them. How costly was/is homosexual behavior? Are the costs high or low when you consider the evolution of homosexuality traits (how much do they affect reproduction/survival rates)? I would agree that it would be likely that there is a benefit to homosexuality if one could demonstrate high costs throughout evolution of the trait. Though I wouldn't join you in assuming that the costs are such that advantages should be presumed to explain the prevalence. I'm not sure that the observation of other species displaying homosexual behavior is evidence for a benefit in humans, we live in different environments and our fitness landscapes will probably be different. Not only that but the homosexual behavior is quite varied across all of the species that do display homosexual behavior.

Yes, I said in my previous post I am not well read on this topic at all. If you have evidence for the cost to reproduction throughout evolutionary history then please post a link or citation, I'd like to read it.

I didn't really read much of the OP's posts. stopped after I read the curbing population suggestion. If that assumption was made, I'd agree. The CF example was just to show that the cost to survival/reproduction is variable and can change depending on various factors, and that such a situation might be the case for homoseuality genetic factors. I was ignoring any advantages CF alleles confer. I'm not going to repeat my arguments, there has already been a fair amount of repitition. I was only trying to make you question the usefulness of any evidence of reproductive costs you are aware of, because if this cost to reproduction you see today hasn't been present throughout history then an advantage isn't required to explain the prevalence, is it? I have not read any papers on this so I don't know how good the evidence is and whether or not it can be assumed that there has been a cost to reproduction since homosexuality began increasing in prevalence. Would you mind giving me some links to any papers that have information on how homosexuality impacts survival or reproductione rates?

It is not a choice simply because there is no alternative option (which is to believe the elephant is there), since it is not possible (at least extremely unlikely) that I could genuinely believe there was an elephant in the yard.

That was amazing anticipation. I also wander what exactly he wants and how this is any different from the other threads. Why exactly does this bother you so much? Does it surprise you that there are people who maintain their positions, regardless of any counter evidence, on this matter? Are the opinions of people on internet forums representive of the opinions of scientists?

that assumption fine to make when reviewing evidence for a religion though, unless the people that invented the religions had a way of measuring things outside of the universe that is fine to make. Considering a creator as a possibility, sure the assumption isn't appropriate. Regarding the whole neuroscience and illusion of choice thing. I don't think there is enough evidence to even suggest illusion of free will yet, there was counter evidence from the experiment that showed the same neuronal activity (prior to button press) regardless of whether the button was pushed or not. Showing that the decision remains unaltered from the point of conscious awareness to the point of the outcome is necessary to suggest illusion of free will. To me, the evidence suggests that there can be an illusion of free will for fast movement. Even if you disagree with this, more evidence is needed to come to the same conclusion about complex planned decisions (quite a few of the experiments told the participants not to plan their movements and just press when you feel an urge). Shouldn't the standard position be free will until proven otherwise? I havn't any experiences of a scenario in which my unconscious has done something that I didn't want it to do (like turn around and shoot someone whilst at a shooting range). It feels like this is something that one could always claim and not disprove, that there is illusion of free will (but how do you know if you really could have chosen the other option at that time?), almost like disproving the existence of an invisible dragon? Anyway, I think some people on that other forum you posted are too supportive of the notion of illusion of free will considering the current evidence. Would you mind elaborating? why do you think the opposite true? I'm curious of your opinion.

Ok, I was kind of ignoring the possibility of someone with free will choosing to believe he/she can't freely believe to point out that such an individual should be able to freely move between different religions. Isn't choice of religion pretty much dependent on the existence of religions (for most people at least)? so the environment has an influence? I wonder if there has been any study on religious beliefs and whether religious belief shows somekind of heritability. This is also my current opinion, although I don't really know much about this topic at all. Doesn't determinism suggest predictability? I am a little doubtful at how accurately one can predict another's decisions. I think this should be done. I'm not that sure what people really mean when they say illusion of choice. In a scenario, at time p, a person has two choices a and b. the person selects choice a, choice b is considered the illusion? is it only considered an illusion at time p, or is it always an illusion and not ever an outcome? that is where I am getting confused.

So if decisions are made before we are aware of them and choice is an illusion, then does that mean we have no control and are essentially automatons? If choice is really an illusion then how does the decision process work and how is the outcome determined/selected? Do you have any links to the actual neuroscience papers? I looked at the first page of that other thread you linked, but that was just a quote from the book or the author's blog.

I thought your reply to be odd until I saw that I wrote "possible". I meant likely. What would you answer to Cuthber's question? or could you freely switch to another religion? hmm, illusion of choice? in what way could choice be considered an illusion? are you referring to fatalism?

If one has complete free will then one should be able to freely change beliefs at will and be able to commit to each belief fully (actually believe in it)? right? Personally, I don't think this is possible for this scenario. I think that genetics and the environment influence the outccome as others have suggested. I couldn't win the prize in John Cuthber's scenario, I would be a liar and I could not imagine any (likely) scenario in which my opinion would change. After considering this question on belief choice it seems that some decisions have less freedom of choice than others. Example of something I think of having little freedom of choice, attraction. Example of freedom, whether or not I decide to flip a coin.

X-inactivation does not cause gene silencing for all genes along the inactive X in a normal 46 XX female. There are a group of genes which can escape x inactivation silencing. So this can probably lead to haploinsufficiency effects that can cause some of the Turner syndrome symptoms and physiological features. There are also imprinted genes on the X chromosome, and this can also contribute to some of the Turner syndrome defects. In case you don't know much about imprinting, this means that some of the Turner syndrome defects and symptoms can be caused by gene silencing of various genes which is dependent on whether the inherited X is inherited from the mother or father. A normal female will usuall have 50% of cells expressing a paternal X and the other 50% expressing maternal X, however in Turner Syndrome there will be either 100% paternal or maternal X. The defects and symptoms can vary depending on parental origin of the X in someone with Turner syndrome, such as increased risk of coronary artery disease when the inherited X comes from the mother. It pretty much comes down to expression differences caused by X inactivation escape and genomic imprinting.

This is exactly the type of mentality I was warning against in my previous post! Using observational evidence you see today and then extending it to the whole of the evolutionary history of the genetic components of homosexual behavior. Is it really appropriate? I don't think it is. The level of selection for a trait can change over time, and I was not claiming homosexuality is neutral. I was merely suggesting that it is possible homosexuality might have been neutral or at least have a small cost to reproduction, and so might have risen in frequency randomly or by genetic hitchiking etc. Consider cystic fibrosis, at very low frequency, individuals with CF alleles will have practically the same average number of children as the rest of the population as the probability of two carriers comming together is very low/0. As the frequency rises the strength of selection against it will rise however as the difference between CF carriers and non-carriers average offspring numbers will become larger. So in the beginning of CF it wouldn't have been under strong selection would it? most likely neutral. Maybe it has been only recently that homosexuality behavioral traits have had much of a reproductive cost. I'm just saying assuming the fixed cost to reproduction that you observe today and assuming it through out history is silly, what if the cost has been negligible for a long time such that the frequency could rise. Or what if throughout history the frequency of exclusive homosexuality has been non-uniform, and has been rare for a long time (up until recently)? This mentality is quite common, there are quite a few threads like this. "How can homosexuality ever reach the prevalence it is at today when it has such profound effects on reproduction?". To me, you are just answering this question by assuming it is advantageous. I don't even see the need to even try to attach advantageous or disadvantageous to genetic contributing factors of homosexuality. We only know of one or two loci which contribute, we don't really know the allele frequencies, we don't know how the frequencies have changed at the population level, we can't observe the nucleotide sequence changes. So we don't really know if the frequency of homosexual behavior is at a level which suggests there is an advantage or not. Since your response suggests you assume there is a cost to reproduction. I'd like you to supply evidence that this cost has been there throughout history, such that an advantage to overcome this cost should be needed to explain today's prevalence. Again, be very careful when you assume there is a cost to reproduction and that this cost has been present since homosexual behavior's evolution. Just because there might be a cost today does not mean there has been one since long ago, and observation of a cost today therefore might of little relevance.

YY in humans have never been observed, right? where as many other possible anueploidy and polyploidy of sex chromosomes has been observed. So probably not compatible with life. Also. Your special medicine will need to be able to induce a female genomic imprinting patern in one of the guy's germline cells. I don't know at what stage genomic imprinting is erased and reprogrammed as male in germline cells though. A male male imprinting pattern might not be compatible with life, I have no idea if it is compatible in humans or not. Even if it is, the baby would have many defects I think. So either the medicine or some other treatment will be neccessary to create the normal imprinting pattern. This imprinting pattern will probably be the most difficult issue to rectify in a real life foetus with two fathers using a surrogate mother, mitochondria could just be injected in I'd imagine. We don't know much if anything about the sex specific imprinting that occurs in germline cells at the moment. baby with two biological fathers should be possible in the future, legal in the future is a different issue heh.

I agree. Although, the point of it was that we currently have no/little knowledge of the benefits of homosexual behavior in humans. I still think you should apply this quoted response to your own statements. Not sure why you keep saying that, when there is more meaningful suggestive evidence for a genetic basis in humans. Heritability studies. I strongly disagree. I don't think the liklihood is high enough to presume it. I think that the level of selection throughout history for homosexuality is a very important factor in this discussion, but unfortunately it is one which we have practically no information about. I'd take a guess that the level of selection might be a common contributor to people's opinion on this topic, and one which I think is possibly being assumed without much thought (by using observation about homosexuals today and applying it to history as well, and in overtone's case usage of darwinian logic). I'd think it inappropriate to assume that gentic loci which contribute to homosexual behavior will be selected against strongly, selected against weakly, neutrally, or positively. Consider them all! You are using observational evidence to suggest that it should be standard to presume that homosexuality traits confer reproductive benefits, this does not need to be disproven as it can be trashed quite easily by simply asking you to provide real evidence for it (many theories can't be disproven but it doesn't make them true). Whilst you might presume that there is a benefit, you should also be willing to admit that there is an x% probability it is correct with x being totally unknown. Yes? if not, why. Personally, I think that the importance of the historical selection is too great to assume it being this or that with no evidence. Depending on what assumption is made (high -ve selection, low -ve selection, neutral, +ve selection etc), I can imagine differeing conclusions will be produced. We don't know whether or not it has been under selection or whether or not it confers some advantage or disadvantage. You are simply eliminating possibilities using weak evidence, but what if homosexuality has largely risen in frequency due to it being a neutral trait? would you say that the hitchiker's thumb must be at it's prevalence today because of a survival/reproductive advantage? same question can be applied to anticlockwise hair whirl, ear wax, (insert any neutral trait). Did you know that neutral traits can rise in frequency too? if so, why is the possibility ignored. This is what I suggest you do. Don't ignore genetic drift. Be very careful when considering historical selection for or against homosexuality. Consider all possibilities and question whether the particular behavior in question does contribute to some change in average number of offspring or not(is it really under selection -ve or +ve???). Don't place too much value in observation or the standard "it is prevalent so it must be beneficial" line of thinking. Currently, we know of no benefits that homosexuality might confer to humans now or in the past. It isn't terribly logical to presume there are.

The ability for us to invent is an adaption that can lead to the evolution of inventions, where as other traits like the beak and nut are relatively fixed. Testing new solutions by mutation is restricted to 20+ year generation time for human genomes, but testing new solutions for our inventions does not have this restriction and can occur outside of the genome. Externalised evolution like Tresjuicy said. A comparison between the evolution of inventions and our genes/genomes might be quite interesting (and if not, fun), somehow testing the improvement yields of evolution for an invention (%improvement/year?) compared to a gene which has improved the most over the smallest number of generations. Then going more general and comparing ability to invent to other traits and comparing the relative advantage they confer? Obviously this is difficult, but to look at invention evolution vs genome evolution and exploring the relationship between the two in general might interesting. I just realised this is a fairly old thread, but I guess i'll just post what I wrote anyway.

I have not addressed the question because there is no meaningful evidence to suggest homosexual behavior has been under positive selection. I presented the view that it isn't appropriate to assume there is a benefit, until there is supportive evidence. Would you say that all genetic disease alleles have reached the frequency they are at today because they confer selective advantage, by automatic presumption because they can result in survival/reproductive hits and so should have been eradicated long ago? Yes, I didn't address that question, but we are not really in a position to address though. I don't understand why this presumption should be made, please explain. Not a typo, except i shouldn't have written cannot. If genetic factors which contribute to homosexual behavior are highly penetrant then those factors should be almost completely associated to individuals that display homosexual behavior, and therefore be fairly strongly selected against depending on how much of a hit to reproduction it causes. It is suggested that there are genetic components to homosexual behavior in humans, not because of those observations, but because of the estimated heritability from numerous studies.

Except one can effectively break the association between pleasure of sex and procreation, that evolution created, by using contraception, so that the probability of getting pregnant is practically 0. I'd agree that the mechanism is not flawless. There seems to be no obvious benefit to the behavior, but whether or not is has been under positive selection or not isn't clear. How much do you think those can explain though? Attraction seems to be subtle and complex, could genetics/environmental factors ever explain why an individual finds some people more attractive than others? I don't see the logic in that reasoning. The choice aspect mainly stems from attraction I think, in that homosexuals are homosexual primarily because they are attracted to the same sex. I've heard people say that they feel as though they didn't really actively make the choice to be homosexual because they didn't choose to be attracted to indiviuals of the same sex and they couldn't change it even if they wanted it. I think when they say they were forced they mean they didn't have the choice to be attracted to the other sex. They might choose to participate in homosexual behavior but did they choose the underlying attraction to the same sex? contraception is the transcention? anyways, can't the underlying reason for the two men winding up in bed together be explained by some of evolutions other creations, attraction + pleasure of sex?

Overtone I think you have let your assumptions grow unchecked, like weeds. Weed killer application might be appropriate. Your posts have gradually become more and more inappropriate. Whether or not benefits do or don't exist is not the important question. If homosexual behaviour as a trait were to have some advantage then you should ask if those benefits are strong enough to allow for the genetic basis for the trait to rise in frequency. Since the genetic basis for homosexuality is not understood so well in humans, but suggested by heritability, such studies are not meaningful. To also extend these studies to imply that these benefits existed a long time ago, ,which would allow you to suggest that the traits rise in frequency may be due to these benefits, is inappropriate. Those studies and research you refer to don't offer much, if any, meaningful data/conclusions. In my opinion, the argument should not go beyond how likely it is that homosexual behanvioural traits confer selective advantages as there is no/very little evidence suggesting that there is or isnt. Assuming either possibility isn't appropriate as it is an open question whether there are or are not selective advantages. You can't deny the possibility of genetic hitchiking, selective sweeps etc as mechanisms which could have contributed to the increased frequency of genetic components to homosexual behavioural traits though, can you? When you say that you are not talking about a leftover from former times, that is assuming that there is very high penetrance and that a genetic component that contributes to homosexual behaviour cannot be found in an individual that reproduces. Proove the high penetrance or take back the statement. It is your perception that a homosexuality trait should in theory be wiped out from the gene pool very fast, but that might not be the case in reality. This contains far too much speculation and deduction from your own personal observation. Firstly, this argument also assumes high penetrance. The trait itself varies, and some individuals with the trait do reproduce, there could also be an underestimation of homosexuality behaviour due to social prejudice. If I had made those assumptions you made then I would have been in agreement more often. The issue is not simple and all possibilities must be considered. Labels are all we really have. In a similar way to skin colour, there is no strict melanin index score that the entire general population uses to term someone as white, is there? I havn't read much of this thread but I'd imagine it is hard to tell if people really do think that homosexuality is not a continuum. Same sex attraction should also not be ignored in homosexuality discussions.

I don't think what he said is pointless. I agree that the die roll is random and I think he knew that. Natural selection/fitness landscape is the guidance he was referring to I believe, as you said in that quote, and it does alter the probability that a particular mutation can survive over generations. I'd agree that such long term prediction like that would most likely be impossible, but prediction over much shorter time periods could be possible.

There was not a clear concept. I really didn't give any thought to the usage of the word "law" at all when I created this thread. It should really have been a question, as I was hoping for some people to give their opinions on evolution/natural selection/fitness landscape and whether they are laws. I don't really have much knowledge of this topic and I was only suggesting that mechanisms of evolution are capable of change over time. I then went on to ask about the law stuff and how this change might be explained. After having read Ophiolite's informative post I would agree. I briefly looked into chaos and catastophe theory, and from what I read it seems as though that rigid, deterministic laws can give rise to chaos? So it should still be possible that such laws could govern evolution and the universe. Although I did not specically state it anywhere, I was considering both conditional law and clear-cut law as possibilities. Ophiolite said, "Laws are, for the most part, nothing more than quantification of simple relationships established via observation". I would change that sentence so that it said "Currently, laws are...", since it is probably easier to identify conditional relationships that work in one condition than to identify a law which holds in any instance. I would agree with your argument, but I would again have used the word "currently". Maybe the difficulty of identifying and determining biological laws is too great at the moment. The example I used in a previous post was natural selection/fitness landscape, the difficulty involved in determining the shape of a single fitness landscape (for a given trait, in a given environment, in a given species) alone is a massive feat let alone trying to identify any simple relationships or laws.

because they are both heritable mutations. Germline mutations are the only ones which are heritable in a human, and thus the ones that are most critical to evolution. That phrase is not necessary for the 3.6-3.8billion year ago algorithm as somatic mutations are heritable, but it is necessary for a human one as somatic mutations are not heritable in humans (and cannot contribute to generation of diversity in the next generation). I suppose you are right, "generation of variety" could be substitued in to replace many of the mechanisms I included. I decided to break evolution down into more specific steps to get the point across. I guess it should be the mechanisms of evolution that can change then.I'm not really sure why you would rather have "generation of variety" in there at all, it is quite vague as there are many different ways for this to arise (which was my point). I'd agree that the general process of evolution remains unchanged though.

I agree that we are restricted to observation of life on Earth at the moment and that this is a problem when trying to answer these questions. However, whether or not there are any other life forms, trying to identify to laws is a massive feat itself. To try and come up with an accurate law/equation for natural selection/evolution/fitness landscape would be pretty hard. We can detect some these things without too much difficulty, but to come up with laws/equations which allows us to accurately predict that x trait will rise in frequency by x% in environment y with a d% probability (just an example) seems far off! As far as I know, it is difficult to quanitfy the level of different types of selection that could be operating (infuence of sexual selection seems to be difficult to assess) and there is also the problem of determining the cause of the various types of selection for particular traits (reason why a trait is advantageous). Then there is the fitness landscape, how does one determine what the fitness landscape is for a trait in a given environment and species? Would you mind elaborating on your view? which laws are you referring to when you say you can't think of any which only apply to evolution? And what do you mean when you say evolution is a process? how the process relate to the laws of nature/universe? To dmaiski: I'm not really sure what your point is in relation to my initial post. The non-recombining region of Y is not relevant to this discussion? Your posts don't seem correct at first sight to me, so please explain.

I don't really see the relevance of this. what?

This topic is to expand on my previous posts about evolution and how it is capable of change and to ask questions about evolution/natural selection as a law of the universe. I previously used the term "learning" and improvement, however i will not be using them here since they are baseless assertions. I hope more than one person responds this time! To suggest that evolution can change over time, I'll write evolution as a simple series of steps or an algorithm (just a basic rough one to get the point across, extremely simplistic and ignores complex things like endosymbiosis etc.)) for early life forms 3.8-3.6ish billion years ago and one for todays descendants. These are the basic core steps of the evolutionary process that applies to all individuals of the population. I'm not going to write natural selection as a step, not really sure if that is appropriate (should be applicable all the time?). 1. might be better off as being an individual, not sure. 3.6-3.8 billion years ago: 1. population 2. mutation rate 3. reproduction 4. cycle back to 1. This is relatively simple, you have the population which is then subject to a mutation rate and then reproduction occurs natural selection applying. algorithm for a human: 1. population 2. germline mutation rate 3. non-random recombination (PRDM9 genotype dependent) 4. random assortment of paternal and maternal chromosomes 5. non-random partner choice 6. random fusion of gametes 7. cycle back to 1. These are the core steps of human evolution (roughly). If one were to do one for bacteria horizontal gene transfer would be in the list. The is just a simple scheme I made up in a few minutes, I realise they are not 100% accurate. Just used to illustrate a point. Basically the idea is that the fundamental process of evolution is capable of change by looking at the difference in the core steps of evolution from 3.6-3.8 billion years ago and now. An Interesting question is what does the real algorithm look like (the one which changes over time, adding/removing new steps)? How does one come up with a generalised definition/description of evolution when potentially, the algorithm could be altered further over the next billion+ years (such that new mechanisms for evolution arise)? This part is asking questions about evolution/natural/fitness landscape as laws of the universe. Is evolution like a more complicated biological equivalent of V = I x R for example(of course with randomness in the equations)? Was the fitness landscape/natural selection for all possible environments and all possible animals determined shortly after our universe arose (like physics laws were) or does it arise spontaneously as the environments themselves arise? Is everything subject to natural selection? Was evolution determined as a law of the universe shortly after the universe arose, if so how is the ability to change explained? I'd like to hear people's opinions to any of these questions. What do you think about evolution and it's ability to change (as an algorithm)? Likely or not? Even if you think this is trash, I'd still like to hear it, and your reasoning.

Bacteria have had a few more generations to evolve than us, so that is expected. I wouldn't say evolution is a failure because bacteria have had more opportunities to evolve than we have. We still exist despite the extremely large difference in generation time, so there must have been some advantage to compensate for this.