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jp255

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Everything posted by jp255

  1. My unborn offspring, which don't exist yet, are my friends? They arn't on my facebook list tho! I guess I should have said before, but the I am interested in the explanation which takes into account fitness/selection. That explanation only tries to asnwer how the situation arose, not why.
  2. jp255

    Gay gene

    I have already given my opinion on whether or not it is a choice. I think it is likely that sexual attraction is not a choice, but ultimately there is a choice to engage in homosexual behaviour. I just said it is pure speculation and opinion because it is so hard to prove, and I did not previously say that. I never intend to make assertions with 100% certainty, there are probably examples of me saying things suggesting high certainty though. Also, you were not being mean at all. Try reading the statement you quoted again. I don't believe I twist the meanings of everything around and then interpret them as the opposite like you just did. I am aware of the impact of the environment. However in this instance I am not so quick to dismiss the involvement of genes because sexual attraction/partner choice is highly non-random in many animals, and genetics does play an important part in this process.
  3. jp255

    Eugenics

    Don't you think that dominant, highly penetrant diseases such as Huntington's disease should be eliminated? I think Huntington's disease should naturally eliminate itself by personal choice not to reproduce, or to reproduce via preimplantation diagnosis. I definitely agree with you about recessive genetic diseases. Using eugenics to get rid of recessive genetic diseases will take a number of generations. Using PGD to prevent the occurence of the disease will eventually result in it being eliminated though, people must have knowledge that they are carriers however. Best bet is to wait for technology that allows for deleterious alleles to be replaced. As for positive eugenics. I wouln't implement a positive eugenics program on a nation. Forced sterilisation is too extreme. Whilst I did see the point in one of your posts in the first page about jersey shore and twitter, however that is nothing more than mine (and probably your) personal dislike of how the majority choose to live their lives. It really doesn't make a difference though, they can still live like that, survive and reproduce. They can easily be as fit as someone with an IQ of 150. Intelligence isn't worth selecting for because of this, it has little relation to fitness. And finally the most important points: does Jersey shore prevent science from progressing? does twitter? To the point that you think positive eugenics should be enforced? Are there no unemployed individuals with <insert degree you value>, Which leads you to believe the positive eugenics program will result in increased scientific progression? I don't know where you live, but in my country you can make more money being a self-employed plumber than you can pursuing a career in scientific research. There are porbably some would-be scientists working in higher paid jobs because it is not valued highly. I'm not sure there is a desparate need for more high IQ individuals.
  4. jp255

    Gay gene

    That is the biggest limitation in my opinion. The accuracy and the errors are also unkown. How can the impact of prejudice against homosexuality even be detected? Learn from that post then? I can't recall understanding your points. The choice argument is pretty much total speculation (no can prove how homosexuals think), or at least relies on very imaginative extension of evidence from other species which is barely considered suggestive.
  5. I am interested in the process of evolution. What do you offer to explain the high amount of sexual reproduction among species with high generation times, and the opposite for species with very low generation times (where asexual reproduction is the main mechanism)? Your creative analogies? How do you propose I spread my traits to my friends then? Again, HGT =/= sexual reproduction.
  6. I agree, at the moment. It hasn't really been explored much, but if you compare evolution to man made evolutionary algorithms, one can potentially find solutions that can improve the rate of evolution (maybe it is best described at average fitness gain over generations, as opposed to the number of generations it takes to find fittest allele) and the other cannot (at the moment at least). It is definitely something I would imagine to be more advantageous for a plant that is fixed in it's position than for an organism capable of movement. The problem is really determination of fitness, there are other examples of stress leading to heritable changes but no studies I know of have related them to increased fitness. That is exactly what it is. The risk of death is higher (assuming stress in an indicator), so more of a risk is taken in attempt to find fitness gains.
  7. An improvement is something which causes a reduction in the number of generations it takes to find the fittest allele after a change to the environment. The it is no longer an improvement point is definitely a possibility, which is why the term learning was used. Anything which causes an increase in the number of generations it takes to find the fittest allele should be selected against and eliminated. The easiest way to show that evolution is capable of self improvement is by using simple mathematical models, it would be extremely difficult to show using real examples. Maybe this has been done, but the model needs to make a random fitness landscape for some genes, keep the population number constant, reproduction rates constant, assume random mating and random cross over. Then run the model at differential mutation rates many times. I'll use a relatively simple example to show that higher mutation rates can be better in times of stress. consider two populations A and B. They each consist of the same progeny(identical), but just under different conditions. Assume that deleterious mutation = death. Assume beneficial mutation rate is deleterious mutation rate/10. Assume that the deleterious mutation rate and death rate are population averages (can be applied to all individuals). Pop A has a deleterious mutation rate of 30%, and a death rate of 50%, 30 will die from deleterious mutation and 50 from stress (e.g predation). Pop B has a deleterious mutation rate of 2%, and a death rate of 50%. In pop A, 30 individuals will have a denovo deleterious mutation and die but some of these individuals might have died themselves from stress had they not have had a mutation (15% chance, on average 15 individuals). In pop B, 2 individuals will have a denovo mutation and die, but some of these might have died from stress had they not have had a mutation(1% chance, on average 1 individual). In pop A, 15 died from deleterious mutation 35 from the death rate and 15 would have had both occurrences. 35 individuals remain alive. Probability an alive individual carries a beneficial mutation is 1.05. In pop B, 1 died from deleterious mutation, 49 from death rate and 1 would have had both occurrences. 49 individuals remain alive. Probability an alive individual carries a beneficial mutation is 0.098. Overall, Pop A has a 15 times higher mutation rate than pop B. The probability an alive individual carries a beneficial mutation is 10.7 times higher. My math is probably wrong somewhere! When the death rate is high, it can be advantageous to increase the mutation rate because some individuals would have died even if they had not received a deleterious mutation. Therefore, the cost of deleterious mutations is dramatically reduced in times of high death rate. Also, even when the death rate is 0, there will still be more beneficial mutations for Pop A, the point is that increased mutation rate can be elevated to search the fitness landscape quickly as a short term solution to a problem (stress). This is example is purely trying to convey the potential for an increase in mutation rate increase to be advantageous. In reality it is of course, much more complicated than that. I have no idea if this mechanism has been shown to relate to fitness in any studies, otherwise I would have posted links. I personally think it is advantageous, it makes sense to me to make more attempts at exploring the fitness landscape for fitness gains when stressed as a short term solution(I believe I recall from a paper that the mutation rates rise the more stress the organism is under, need to look for that link). That is just a hunch though, this example assumes that stress is an indicator of death rate or at least a reduction of the individual's probability of surviving (and also progeny's likely reduction in survival probability also).
  8. jp255

    Gay gene

    Unfortunately the GWAS results are irrelevant to this debate. The heritability studies don't show 100% genetic contribution. with less than 100% genetic contribution the possible involvement of the environment cannot be denied which means you cannot be sure if mutations are the sole cause (because environmental factors are hard to identify and study). It seems pretty likely that you'd like to be able to say your sexuality is caused because of a mutation, you gave no reasoning at all and admitted not having any evidence. I presented the opportunity for you to admit it to yourself for your own good, but you chose to evade.
  9. jp255

    Gay gene

    With no evidence how do you know this will be the case? Homosexuality is complex and it is unlikely any one factor can explain an individuals sexuality alone, thus any one mutation should not be said to cause homosexuality, but rather, contribute to homosexuality. It is exactly the same when people say smoking causes cancer. It doesn't, it contributes to it's development. Saying something causes x trait implies that in an identical situation, absence of the something will not result in the x phenotype. That is not necessarily always the case. Just admit you'd like to be able to attribute your sexuality to a mutation?
  10. Yeah, I understand the point about asexual being common. To convey the likihood that sexual is more efficient in terms of rate of evolution I mentioned the strong correlation of sexual reproduction to high generation time. This is pretty obvious, but you do raise a good point about some species using both mechanisms. However, there are various indicators even within these species that sexual is extremely useful in times of stress. Some species switch to sexual reproduction when under stress, I'd have to look for the link but I think it was yeast I read about. This is a very high cost for sure. The way in which sexual and asexual comparison are being done are not that realistic. http://jhered.oxfordjournals.org/content/101/suppl_1/S142.long is an example of a fairly recent paper. Papers like this don't include non-random recombination into the models, which is an advantage of sex. The gene coding for this function has been under very high selection and is one of the fastest evolving genes, citation in the other thread. Allowing for selection of the best recombination pattern allele is an advantage not considered. Maybe this shouldn't be taken into account when considering the evolution of sex though, not sure when non-random recombination evolved.
  11. It might not have any foresight, but it is possibly capable of improvement over time. What I mean is, the evolution of particular traits or features has the potential to improve evolution so that the number of generations it takes to adapt to a change in the environment is lower. Examples of such traits: 1) natural selection of mutation rates. Evolution would be too slow with an extremely slow mutation rate and with an extremely high mutation rate. 2) Stress due to changes in environment can result in higher mutation rates. http://www.ncbi.nlm.nih.gov/pubmed/21236268 whilst this has not explicitly been shown to be advantageous, one can imagine that times of stress where survivability might be reduced the increased mutation rate could be worthwhile. 3) non-random meitoic recombination is controlled by PRDM9 in humans. This can accelerate variability in populations in regions of the genome which have large fitness gains with heterozygosity (such as MHC region). The different recombination patterns themselves can vary and be under massive selection, which suggests that some patterns of recombination result in greater fitness. PRDM9 is also one of the fastest evolving genes http://www.sciencedirect.com/science/article/pii/S0168952511000175 doesn't show the full article but still interesting to read the shown parts. Due to the potential for the rate of evolution to change over time due to some of these mechanisms (and probably others too), maybe evolution could be describe as capable of real-time learning (in a sense).
  12. jp255

    Gay gene

    If the GWAS uses simple terms like "homosexuality" and "heterosexuality" then the opportunity to gain information about varying degrees of homosexuality will be eliminated. Using a scale like the one I suggested, at least allows for some kind of attempt at quantifying the level of sexual attration an individual has to either sex. The identified genetic factors could then be tested for association to the scale values, which could potentially identify genetic factors associated to severe phenotypes (very strong attraction to same sex). Then post the evidence that suggests there are discrete phenotypes. You also still have no answered my previous question about how you know you possess a homosexuality contributing mutation. I'd like to hear your explanation still.
  13. jp255

    Gay gene

    Ok I'll admit, I am a fool. Now will you answer the question? I am interested to hear your response. Yeah. I have not seen any studies that have large sample sizes however. This could explain some of the large variation present between different independent heritability studies. The heritability studies for homosexuality I have seen (so far) just used the terms "homosexual" and "heterosexual" for sexual orientation. In reality these phenotypes can be broken down into a more quantitative trait. If there is a GWAS for homosexuality then I hope they at least tried to quantify homosexuality, maybe a scale from 0 to 100 (0 is complete attraction to female, 100 to male), as well as asking sexual orientation etc. After identification of contributing genetic factors, it could be difficult to explain the heritability (Could be phantom "missing" heritability, quite likely). Firstly the heritability itself might not be that accurate due to low sample sizes. Varying heritability across different populations would mean that the heritability and GWAS need to be carried out in the same population at the very least. Trying to explain the varying degrees of homosexuality will probably be tricky, it might be limited to association only (going on to research the severity or level of homosexuality a genetic factor contributes is very hard). The GWAS should be able to provide data on the relative risk for particular alleles in the population. Of course that is pure speculation, but in general I am very skeptical of the kin selection hypothesis for homosexuality being advantageous or selected. You raise a different point, which is of course a possibility, but the popular theory is that homosexual offspring help care for siblings. I am very skeptical of that theory, despite the evidence suggesting homosexual uncles/brothers give more attention to niece/nephew/siblings. I am doubtful as to how that evidence and theory actually relates to positive selection, because in order for it to rise in frequency there needs to be a higher average number of offspring that reach reproductive age than the population average in the family with homosexual individuals. Due to the varying degrees of homosexuality, it is possible that the level of selection against it could be weaker than you might think.
  14. jp255

    Gay gene

    Yeah, it is high. I was just criticising that statement and the approach you used to say how all mental traits have high environmental contribution. What is it about your face that allows you to tell you possess a mutation which contributes to homosexuality?
  15. jp255

    Gay gene

    No, it's not really basics. I realise that there is an environmental component to mental traits, but to say it is high for sexuality requires evidence. The study itself has to be about sexuality, do all mental traits have to have the same amount of environmental contribution? That assumption isn't really appropriate and extending the conclusions of studies on blind people to sexuality is not meaningful. Homosexuality isn't understood all that well. There are very few known examples of human genetic factors. The evidence for hormonal impact only raises the question "to what extent is hormonal contribution to homosexual behavior genetic and environmental?". Both are possible. All we really have is speculation, and prediction of what we think is most likely.
  16. Don't underestimate the importance of environmental factors. It depends on what the paper contains, but I doubt it would mean much to me if I was the one judging the paper. I'm not so sure that genetics explains the population variance of certain traits that employers look at. Genetics obviously has an important function that provides the basic framework of an individual, but can it explain why some people are CEO's of banks and others work at the supermarket? How much value employers would place on such a piece of paper, I couldn't say. I think it shouldn't have much value though.
  17. jp255

    Gay gene

    I'm assuming that is a response to manfromzurich. You are right when you say we don't have much knowledge of specific genetic factors and it is pretty much speculation at the moment. No knowledge has to be known about specific mechanisms in order to estimate the heritability however. It is the genome wide association studies which are where your criticism will be directed, and I agree with you that each loci found to be associated needs to be investigated. Some could be false positives even after bonferroni. That is an assumption? otherwise provide the evidence.
  18. Yeah. There are not many species which sexually reproduce without having two sexes though, I don't know of any. Horizontal gene transfer is something else entirely.
  19. I'm not so sure that any new traits which do evolve will be able to reach fixation that easily. Survival is not much of an issue in first world countries, and I doubt reproduction differences would lead to large allele frequency changes. It would take a very long time and high number of generations, and most likely the newly evolved trait will have to be under reproductive selection in order to be overrepresented in each successive generation (in first world countries where survival is not much of an issue). Scenarios that could cause significant allele frequency changes or possible rise of new traits is from war or pathogens (like if ebola or marburg virus was able to spread out of Africa), these would probably hasten the rise of allele frequency. It would make room for new traits and allow them to be overrepresented (assuming they survive said catastophe). However, even in this scenario, whether or not the new trait will rise in frequency depends on differential reproduction or survival of the individual (must be greater than population average). I think elimination or reduction of genetic disease instance is most likely to occur, relatively soon. Unless ethics/law prevents it from happening. As the cost falls, the demand for it should rise as more people consider using it to prevent afflicting their child with a disease. I hope it occurs, at least for some genetic diseases. If law/ethics stops it I'd be angry. I couldn't care less about using PGD for designer babies. You were only really discussing evolution regarding genetics and not so much evolutiuon of technology and civilisation, so I'll stop there.
  20. jp255

    Gay gene

    I'm not so sure about that, as I said previously there are quite a few genetic diseases for which the prevalence suggests positive selection despite the obvious negative selection. I believe Cystic fibrosis is one. CF does affect reproduction, but still it is not necessary to limit the argument to only reproduction. This is only one mechanism by which a genetic factor can persist despite negative selection. Genetic hitchhiking is another. Yes, Heterosexual behaviour is a trait. Yes. It does not have to be limited to the Y chromosome at all though. I really don't understand what you mean by "gay gene". You keep talking about genes which alter sexuality by personality, if they can contribute to homosexuality are they not considered to be a gay gene? Any genetic loci which contributes to homosexuality is a part of the estimated heritability. That and the environmental factors determine whether or not someone will be homosexual or not, or to what degree they are.
  21. I can't watch that video right now, but I'll look later. I think we just have very different opinions on what is required in order to call a trait bad. Now you are pretty much contradicting yourself, I thought we agreed that overall sexual > asexual in terms of efficiency. You are not really considering the positive aspects of traits and weighing up the pros and cons of them..
  22. It is not hypocritical because you already stated your opinion in the quote below (taken from an earlier page). You made the statement saying that you see creationism as the explanation. You also replied to my question when I asked about the evidence you would offer for creationism as an explanation, which had no evidence in it ( I realise you know this too as you did refer to creationism as a "belief"). You are biased towards a creationist explanation because the alternative explanation (that the eye evolved), even when considered a belief (as it is in your eyes), should be equally as likely as your own explanation. However, this is not the case as shown by the quote below. That is how I came to the conclusion that you are biased. I simply used rhetorical questions for effect, but you did answer some of them anyway. I'm not really biased against creationist's, that would be quite petty. Anyone is free to believe anything they like and why should I care what beliefs others choose to adopt? Many people are crazy and weird. I was, however, interested to see what evidence would be offered in support of creationism and I gave my overall opinion of your posts in this thread so far. Finally. Would you not agree that there is little point in trying to debate with someone who is biased? and that the points that a biased person makes are pretty much worthless?
  23. jp255

    Gay gene

    I don't think it is very likely either. Sure, that is a possibility. I don't really see how the reasoning you gave is suggestive of this though. This quote and the quote above are contradictory. You are saying you think that genes could contribute to homosexuality by personality changes that lead to more open sexuality. That is a genetic factor which contributes to homosexuality, so it did evolve didn't it. Why? explain your reasoning. So what? you can say the same for many genetic diseases. For instance, no one really knows why some genetic diseases are so prevalent. Last I checked Cystic fibrosis allele frequencies cannot be explained, and the allele frequency it is at today in europeans strongly suggests that it has been under selection in the past. And yes, homosexuality can be compared to genetic diseases because they are selected against in the exact same manner. Which is reduction in the average number of children that reach reproductive age. Also with the whole ending the individuals line thing, this assumes that the trait is either 1) (Full homosexuality (no attraction to females)) is 100% penetrant or 2) dominant trait. Only in these two scenarios would it be a true end of the line for the trait. If you make these assumptions then explain your reasoning. It seems to me that you are not think of homosexuality as a quantitative trait (homosexuality =/= end of the line in all cases, there are varying degrees). We already talked about this in the earlier pages. Penetrance was also brought up in earlier pages as well. Since it is quite prevalent and there is suggestive evidence for genetic factors for homosexuality, I think it is likely that it is a polygenic trait and so the threshold model should be applied where genetic factors are not necessarily highly penetrant. The environmental factors should not be ignored either, as they have the potential to persist over generations and contribute to homosexuality.
  24. Except my view means nothing and is irrelevant. I only deem a sexually selected trait "bad" if it has risen to high frequency even if it is not associated to individuals of higher average fitness or if it results in lower average fitness. To me, this is required. I think it is absurd to describe a sexually selected trait as "bad" without trying to detect possible fitness benefits (indirect and direct). You are referring to the Fisherian runaway. Yes this is a possibility, but this is not true for all sexually selected traits. Using your view point based on this to call traits "bad" isn't really appropriate. A more in-depth examination of fitness benefits is required.
  25. jp255

    Gay gene

    My post was constructive, even if it did contain some acidic adjectives. It raised some questions about your assumptions, asking you to justify and explain. Also, your arguments suggest to me that you were not considering homosexuality to be a complex trait (the whole specific genetic factors for homo and hetero argument), or that penetrance was 100%, or genomic imprinting, etc. Maybe you should be more clear on that. Anyway. The major weakness of your arguments is that they completely disagree with the heritability studies. I also hope you realize how important it is to criticize your own arguments in this instance because if you begin searching and testing various genes/environmental factors that meet your requirements, you might never find a causative factor if you made an error in your reasoning. The meta-analysed heritability studies have low p values, at the significant level. Your opinions, are opinions, nothing more. They don't mean much, especially after reading your illogical judgments. It is a little ironic that you criticize the heritability studies so strongly (which actually have conclusions based on statistical analysis from observational data), and then propose opposing ideas with no logical basis. I have posted the evidence already. Of course, it is not that meaningful because there are next to no studies/literature on human sexual attraction. The arguments I use are: 1) human sexual attraction is extremely non-random 2) sexual orientation and sexual attraction are similar and so the heritability studies can suggest attraction is also has genetic contributing factors 3) sexual attraction is known to be highly non-random in many animal species 4) genetic factors causing changes to sexual attraction/partner choice have been observed in some animals. This batch of evidence, at least to me, leads to me to think that a genetic component to human sexual attraction is likely (even if there is some inference of human attraction based on some other species observations). I have not discussed the genetic mechanisms at all. I do not intend to either, it would just be speculation/guess work. Nor do I intend to discuss the environmental factors either. I would not consider the exact mechanisms, but only make comments on penetrance and other aspects of the factors as I have done.
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