Halucigenia

Take modern varieties of tomatoes for example. The genes are modified yes, but the plant grows similar to a wild tomato plant, obeying the same basic laws of nature (photosynthesis, transpiration, growth ect..). However, the product is not exactly natural. So, can the product be categorized under the man-made section or natural section? In essence we have been genetically modifying crops and domesticated organisms since the beginnings of humankind. It's just that we have taken a slightly more direct approach recently.

Ah, after re-reading this thread I do see a potential for misunderstanding what I meant if this one statement is taken out of context; “that mutations can only be said to be beneficial or detrimental with respect to fitness”. If you read that with the wrong emphasis as I have tried to indicate above you could get the wrong interpretation. What I meant by that was that; mutations can be said to be beneficial or detrimental [or neutral] only with respect to fitness I can see now how this might have been misinterpreted. I hope that clears up any misunderstanding. Thank you again. Me too. Yes, of course there are. I'm glad that you do appear to understand me. Good point. It also may be that light coloured skin and other northern European traits are somehow linked and that if lighter skin gave evolutionary advantage by increasing vitamin D production then the other traits just hitched a ride so to speak.

Ah, I think that I see the misunderstanding, thanks questionposter, I wonder if jimmydasaint has the same misunderstanding. Do you think that I meant that mutations are only ever either beneficial or detrimental according to evolution, and never neutral? What I meant was that to be able to tell if a mutation is beneficial or detrimental with respect to evolution you have to understand the environmental pressures that the population of organisms in question is under. As I explained in the sickle cell anaemia example it can be either depending if malarial infection is prevalent in the population. I thought it should be obvious that they can also be neutral as I alluded to above with respect to mutations that are only cause debilitating effects after reproductive age. Of course slight variations in skin and hair colour can be determined to be beneficial or detrimental evolutionarily wise. For example all it takes is for the majority of sexual partners to have a penchant for a slightly different hair, skin, or feather (think peacocks and birds of paradise) colour for the frequency of the alleles for that particular mutation to increase in the population over the generations via sexual selection. That, in a nutshell is how evolution via sexual selection works. Also with other types of selection all it can take is a very slight phenotypic difference to effect an evolutionary change. Anyway I think that the keyword in the above few posts is “deleterious” as it has a very specific evolutionary meaning. It does not just mean that the mutation has a harmful effect on an individual organism but it means that this harmful effect affects the fitness of that organism where fitness in evolutionary theory, as I have explained above, also has a specific meaning. “In evolutionary theory the fitness of the organism to it's environment simply takes into account how likely it is to survive long enough to reproduce successfully and whether its offspring can themselves survive and and are fit enough compete with others long enough to reproduce.” Furthermore, it can only take very slight phenotypic or behavioural changes to affect that fitness enough for mutated alleles to increase in frequency in a population over the generations. This depends on the environment in which those mutated genes find themselves in. Therefore, whether a mutation is determined to be neutral, beneficial, detrimental or deleterious depends on the above factors. Determining this is not as clear cut as some people may claim. I think that we are getting sidetracked here but I hope that I have made my explanation clearer now than previously.

Thank you. I'm still not sure if I am understanding you there. I agree that "many mutations are either neutral or downright deleterious" but I still maintain that in respect to evolutionary theory it is a fact "that mutations can only be said to be beneficial or detrimental with respect to fitness". Of the illnesses that you mention this is still the case for the ones that are known to be caused by mutations. I does not matter to evolutionary theory that for example Huntington's Disease is a pernicious and downright horrific disease for someone to suffer and of course we all should sympathise with anyone that it affects. In evolutionary theory the fitness of the organism to it's environment simply takes into account how likely it is to survive long enough to reproduce successfully and whether its offspring can themselves survive and and are fit enough compete with others long enough to reproduce. The fact that any mutation that in the majority of cases does not cause dramatic disability to those it affects until after reproductive age means that it is not particularly deleterious as far as evolution is concerned, as individuals with this kind of mutation throughout human evolutionary history could have passed it on fairly transparently to any selection pressures. I don't mean to sound harsh but those are the facts and no amount of “caution or balance” changes those facts. On a science forum such as this I would expect that we can be candid enough to explain the facts as they appear without being so over-cautious that the explanations might cause offence so as to obfuscate a good explanation by declaring any particular mutation deleterious when, in the proper scientific meaning of the word in this context, it is not.

What about them? Are you trying to ask me something?

To put it simply (hopefully); evolution is the change of allele frequencies within populations of organisms over time. Alleles are different versions of genes. Different versions of genes arise via mutation. Different versions of genes provide variation within populations of organisms. Therefore, mutation "drives" evolution by being the source of variation from which natural selection and genetic drift can change the frequency of different alleles within populations of organisms over time thus giving rise to the genetic diversity that we see throughout the living world. Once different populations of organisms become sufficiently different as not to breed with each other speciation can occur and the resulting populations of organisms can continue to diverge genetically since their genes no longer mix in a single gene pool. This is all due to those mutations occurring in the fist place to provide the variation to enable evolution to proceed. Thus mutation is not just a help, it is essential for evolution. Sickle cell anaemia is a very good example of a mutation, one that even though it is potentially harmful, is retained in the population because it is also beneficial given the right environment i.e. that of the presence of malarial infection. This illustrates well the fact that mutations can only be said to be beneficial or detrimental with respect to fitness, that is the fitness of the organism to it's environment, as given one environment – one without a high incidence of malarial infection the mutations potential detrimental effect of sickle cell anaemia would be perceived to be detrimental. While in an environment with a prevalence of malarial infection it is positively beneficial for individuals to have the mutation in at least one of their alleles (heterozygotes).Sickle cell anaemia is also illustrative of the effect of overdominance of genes that have different alleles affecting homozygous and heterozygous individuals differently homozygotes having either no protection from malaria (ones with both alleles not having the mutation) or a dramatic propensity to sickle cell anemia (ones with both alleles having the mutation, and heterozygotes (ones having both a mutated allele and a non mutated allele) having a partial resistance to both. This is very instructive in an understanding of how evolution operates due to changes in alleles frequencies. See above. While mutation is “a sudden and spontaneous change responsible for changing a gene” it has potential to change the frequency of alleles in a population of organisms over time as it can be passed on to subsequent generations and may, if beneficial or neutral and “lucky” (see genetic drift) increase in frequency in the gene pool over the generations.As CharonY says, it is useful to look at evolution as an effect on a population's gene pool over time rather than to concentrate on an individual with a mutation.

The Honeyguide? Not so much about memory but the bird has knowledge of where the honeycomb is and imparts that knowledge to other species - honeybears and humans.

Agreed, there are several possibilities:- Theist - believing in god/gods Atheist – lack of belief in god/gods Gnostic - with knowledge of ... Agnostic - without knowledge of ... Therefore one could be a:- Gnostic theist Agnostic theist Agnostic atheist Gnostic atheist So for example one can be an agnostic atheist i.e. one that lacks a belief in god/gods but does not claim to have knowledge that no gods could possibly exist. Anyway the thread should be about atheism and the advantages thereof according to the title. So if we can clear up what atheism actually is and is not then that should help the discussion as there do appear to be many misconceptions regarding exactly what atheism entails.

All right, I’ll try to explain in detail now that I have some more time.The scenario I described does not give them a choice to become theistic until they hear or think of a god to be theistic about. Just because they do hear or think about a god and voice the opinion that they do not believe in one does not change them – they remain atheistic. If they also additionally make the positive claim that a particular god that they have just heard of or thought about does not or can not in fact exist only then could they said to be claiming a belief. (To me a belief in the non existence of something seems quite a peculiar thing to believe though.) This positive claim does not however change them into being an atheist as they do not change from what they were in the first place (already being atheistic) to something else. Atheists that do make this positive claim make it over and above their original atheistic lack of belief. Atheists today that chose to become atheistic after being theistic do change, they make a choice from believing in something to not believing in something but they do not gain a belief, they lose a belief. What they do is to make a choice establishing that they no longer believe in a god. I would additionally claim that they are reverting to the default position of atheism as I think that everyone is intrinsically atheistic, i.e. lacking in belief of gods, until they are taught about gods and make the positive decision to believe that they exist. Atheism is not necessarily an opposite or opposing belief to theism (an opposite or opposing position, stance, view or opinion would be a better claim). Even if the atheist also makes the positive claim that it can be shown by evidence or reasoning that a particular god does not in fact exist this does not define their atheism as they may also be non committal (lacking in belief) about the actual existence of the other claimed gods (or ones that they do not even know about) that they also lack belief in. The point is that they do not have to make this positive claim to become or remain atheistic. Personally I consider myself to have remained atheistic all my life, never having actually believed in any gods. If I am told about a particular god and have this god’s characteristics defined to me and find that these characteristics appear to be incompatible with reality as I understand it, then I may additionally claim that this god does not in fact exist, however, it is not at this point of claiming that this particular god does not exist that I become atheistic as I was atheistic before making this claim. I would still be loathe to state that I have a belief that this god did not exist though as I just can’t get my head around having a belief in the non existence of something. I have a hard enough time understanding why I would need to believe in anything when I tend to gain knowledge of things through understanding the evidence used to explain things, never mind believing in the non existence of something. Of course in normal conversation I will use common language by stating things such as “I don’t believe in gods, fairies or invisible pink unicorns” etc. Or alternatively “I believe that the sun will rise in the morning, that aliens might exist or that evolution explains the biodiversity of life on Earth”. But that does not mean to say that I have a belief in these things in the same way that a theist has belief in a god or gods. However, it must be stated that I have arrived at these conclusions through knowledge gained by the understanding of the evidence for or lack of evidence and evaluating the possibility of these things existing or not. I do like the aphorism:- “I only believe in that which is impossible” Which I take to mean that I would only have to believe in something that I thought that was impossible to have knowledge of through an understanding of evidence used to explain it. As far as I can tell it’s a matter of belief and faith that enables one to be able to believe that gods exist. It’s not really possible to have knowledge of gods existence through understanding any evidence used to explain their existence as there is generally a dearth of evidence or even logical reasoning brought forward for their existence. Even when evidence or reasoning is attempted to be put forward, in my experience, on investigation it just does not stack up. Therefore, due to this lack of convincing evidence or reasoning I remain at the default position of lack of belief rather than actively believe in them or actively believe in their non existence (if actual belief in something’s non existence is actually possible at all). I admit that it is difficult to put these points across to theists but hopefully I have gone some way to convincing you that you don’t have to hold a belief to be an atheist.

Precisely you just aren't getting it yet, are you? Do they? Disbelief of someone else's belief is not a belief. ...bullshit out there on the interwebs.Why don't you respond to the actual content of my post? If, as you claim, you are a deist, why do you take any stock in the biblical mythology of the christian's religion?

So, putting this claimed faith to the test, can you answer me these questions:- Are you and your religious/deist friends, relatives and/or acquaintances all happy when they hear that someone close to them has died? Do you or they congratulate someone when they tell you that they are about to die? Do you really know of anyone who, on their deathbed, has actually welcomed their own death rather than being afraid of it (not because of, for example, the relief that they would get from a painful condition.)? I would suggest that the greatest benefit one could* have as an atheist is that one can live their life to the full realising that this is the only chance you have got to enjoy life and to participate in other’s enjoyment of it. It would be much better to think this way than to narcissistically dwell on the illusion that this life is only temporary so that anything bad that happens in this life does not matter as much for you and others (others that may not even have the same beliefs as you do) as there is a possibility of something better coming, something that no one can possibly know that will ever actually happen. As an atheist one should* hold life as something that is more precious than a religionist that believes in afterlives would, as we all can only really know that we are going to have just this one. No amount of false hope, faith, belief and prayer, that things will eventually be better could make things actually better in the here and now. As for religious doctrines that suggest that we should have to put up with suffering in this world as some part of a divine plan I can only hold contempt for such psychologically and socially damaging notions. Me, I would prefer to have the real painkiller, the real drug and cure for this life’s potential illnesses rather than some false hope or placebo effect. As for the majority of the OP, all you seem to be saying is that belief, faith and prayer can make one “feel” better. However, personally, I cannot see how this is a defence of theism or deism as it does not make it any more true. Personally I cannot make myself believe or have faith in something just because it might make me “feel” better. Is it really that way that people with a religion/theism/deism think, that they are deluding themselves with the comfort that they feel that their religion gives them because it feels good even if the beliefs that they hold are not true, that they just keep on believing them anyway? That seems like a very poor reason to continue to keep believing in anything. I also find it strange that, as a claimed deist, you seem to be putting up a defence of religion using the theistic religious notion of an afterlife and use an account of the biblical creation myth of genesis claiming that science agrees with its sequence (when it patently does not) in an attempt to question the atheist position. *Of course, as has been stated by others already, to be an atheist all one has to have is no belief in gods. No one who is atheist has to have these epicurean views on life, however, it does seem more likely for an atheist to hold such views rather than a religionist, particularly religionists that believe in some kind of afterlife like you appear to be promoting. I don’t think that you are being technical or precise enough. This may be true, however, that does not make it necessary for an atheist to have a belief system that is directly related to atheism. No, you are missing the point. The point is that there is a difference in believing that something does not exist and lacking a particular belief. No, it does not make sense at all when you understand that atheism can be defined as lack of belief. As such atheism is the default condition. Before anyone thought up the existence of gods everyone was an atheist but would not have understood the term. As soon as the first person to think up a god started believing in that god nothing changed for anyone else – they did not suddenly have a belief in the non existence of this god that someone just thought up. How could they before the idea was even communicated to them. Once this idea was communicated to them they then could take the position that they thought that it was true that this particular god did not exist, however, even before that decision they would still technically have been atheists. Then you should be able to explain what ideological comprehensive vision it is that all atheists hold because of their atheism. What philosophical tendencies or political ideologies that all atheists hold because of their atheism. What set of ideals all atheists hold because of their atheism. etc. etc. etc. The only conformity that atheists have is that they that they have a lack of belief in gods. If you did not know that anyone believed in gods or before anyone believed in gods the term atheist would be redundant for you and only of use in hindsight and as an ideology it would be non existent and impossible to have for you to have. The fact that some people who lack belief in gods may tend to have similar likes, dislikes, opinions etc. does not make atheism an ideology.

Thinking again about what you posted I will have another go at understanding what you are implying (never mind that fact that I think that you are misunderstanding the context of the point about the "first mutation"). By “the first mutation” do you mean that from an arbitrary starting point in time the first mutation to arise in a population from that point in time will be unlikely to be beneficial? If so, then, yes, that is obviously true as beneficial mutations occur less frequently than detrimental or neutral types of mutations. It’s just that the beneficial ones are the ones that tend to get promoted due to natural selection. However, (and this has really been puzzling me hence the return to this comment) even if that is true why would you think that this has anything to do with dinosaurs pre-dating humans and why would you think that this means that organisms are devolving? According to my understanding of what evolutionary theory proposes dinosaurs pre-date humans because evolution from the dinosaur’s common ancestor predates the evolution of all mammalian forms from the mammalian common ancestor . While mammals and dinosaurs do have a common ancestor, that is even further back in time than both of their respective common ancestors. The respective lineages will have generated different mutations and these different mutations will have been promoted due to natural selection acting on the different mutations that were beneficial in different ways under different circumstances in the separated gene pools. Therefore the mutations that arose and have remained in the respective lineages over time since that original common ancestor of both dinosaurs and mammals are mainly those that have been beneficial within those respective lineages. There is no definitive reason why dinosaurs should have had to pre-date humans, it’s just that the contingencies of these different lineage’s different mutations appearing at different times resulted in the dinosaur common ancestor evolving before resulting in the evolution of the mammalian common ancestor, that’s all. Furthermore, these mutations, because of the many splits and divergences along the way, constitute an accumulation of genetic differences through time. This accumulation of genetic difference through time is what we term evolution and goes to show that organisms are evolving not devolving (whatever you intend that to mean). If this bears any relation to what you are claiming and aids your understanding of the apparent misunderstandings you have of what evolutionary theory proposes please let me know.

I think that you are misunderstanding the context of the point about the "first mutation" there.vincentfromyay stated:- Clearly meaning the first mutation in a sequence of mutations that lead to the development of the eye.Not what you seem to be alluding to - the very first mutation ever. Is that in fact what you mean? If any prior mutation to that first mutation in the sequence was not beneficial in that respect it it is not what vincentfromyay, I think, is alluding to. However, see below. Anyhow, whether any mutation is beneficial or not depends on the environment that the organism that it finds itself in is in. So there is no clear cut definition of a beneficial mutation. It is quite true that the majority of mutations are not beneficial but neutral and a lot are also detrimental. However, even neutral and detrimental ones can go on to be increased in frequency within a population especially if you consider dominance and recessiveness between alleles. So if circumstances change these less than beneficial mutations can go on to become beneficial under different circumstances. Also, the first mutational step towards any novel trait need not be immediately associated with that trait itself, it could be something that gives benefit in one way that then is co-opted for another use later in the evolutionary sequence. You still have nothing to back this often repeated (by creationist types) claim up.

I don't see the mountains or lake - I think that the second and third image are more "the right way up". But twining plant, yes, that's it. I was thinking barbed wire or twin chord flex but now you point it out it looks just like a twining plant, something like honeysuckle. I am sure that there's a tree in the background, honeysuckle or similar in the foreground and a shard of green glass or green crystal hanging from a string.

Um, what about parasitic plants, and the fact that Up to 80% of vascular plants worldwide form symbiotic relationships with fungi or bacteria? Although autotrophs are considered the producers in a food chain they often need assistance from other organisms to be able to metabolise. For example chloroplasts in plants themselves are now considered to have originated as bacteria. See:- symbiogenesis and endosymbiosis Does that not constitute a food chain/web in itself? Sure, we can hypothesise about life consisting of strictly autonomous autotrophs. Indeed the very first replicators could have been like that, however, with the diversity that continued evolution produced leading to organisms specialising in different types of chemosynthesis producing competition for resources and diversification of available resources it would seem improbable that diverse life could exist without some form of food chain/web that includes parasitism and symbioses. Therefore, I would consider that life 'as we know it' could not exist at all without some kind of food chain/web. No, it's not a matter of right and wrong but if you want to understand why this simply is what it is, it has to make sense to be able to understand it, for me anyway. Oh, and to answer the OP – an understanding of science can save us from the ignorance and teleological thinking that leads us to suppose that something had to 'decide' that there would be food chains whether that conscious 'decider' is asserted to be a god or nature.

That one just looks like glass shards and bottles hanging from the branches of an out of focus tree.

Looks to me like a photo of someone's crystal growing experiment. I remember as a kid I used to make a saturated solution, take a crystal and hang it on a thread in the solution and the crystal would grow as the solution evaporated and condensed. I'm not sure what compound would make that green colour though it does remind me of a peridot but that's not a mineral that you could grow crystals from though. Maybe you got a picture from Lex Luthor trying to grow Kryptonite. You’re not a relative of superman are you? Maybe it's a threat.

Mutations only have to occurr for them to be able to be passed from one generation to the next. However, they only have to be significant enough to give some kind of survival or reproductive advantage to enable them to increase in frequency within the gene pool to facilitate evolutionary change if that is what you are getting at. As you stated, it only had to be initiated by a tiny light sensitive area. For organisms to function successfully within an environment they have to be able to react to their environment in some way or other, the ones that react successfully survive and go on to reproduce. Any slight advantage in being able to detect electromagnetic radiation - heat and light for instance, that enables them to gain more nutrients, avoid predators etc. will be promoted by evolution. To go from having no eye to having an eye may seem like a large leap but thinking about having no sensory capability to having a slight sensory capability effected by a small molecular change that gives a large advantage to survival or reproduction would seem, to me, to be a small enough step to be much more probable. All a mutation is, is a small change to the genetic material of an organism from one generation to the next so in that respect mutations are always effected in one generation. However, it is better to think of evolution as a population phenomenon i.e. those mutations that arise between generations need to spread within a population over many generations of organisms for evolution to proceed. Evolution is about fixation of mutations in the gene pool within a population.That change from less sensitive to more sensitive detection of electromagnetic radiation being of slight benefit to the individuals that possess the mutation compared to those that don't is all it takes for this mutation to increase in frequency toward fixation over the generations. It does not have to be "vastly complex" as many molecules are photosensitive to some degree all it takes is for them to undergo a chemical reaction in the presence of light and that this chemical reaction be detectable by the chemistry going on within the cell(s) of an organism. Well, everything starts with the first step. Individual steps are small but all that is necessary is for these small steps to be possible to be able to travel long distances. No worries, hopefully I can help you think it through. I'm not quite sure what you mean by "its very improbable to be the first mutation" but see my explanation above. Your statement "other mutations which arent advantageous would die off so the given species which evolved an eye had a greater chance at survival", however, is not a bad summary of how evolution is proposed to proceed. You are, however, way off base with this statement. It is in fact observable that mutations, other than deletions and substitutions, actually add genetic material. As mutation is defined as a change in genetic material any change other than a deletion or substitution is by definition is an addition. Also, even though a a mutation may subtract genetic material this subtraction can affect the genome into producing novel adaptations which can then effect evolution. So your assertion that evolution is backwards (whatever that is supposed to mean) is not supported by your claim that genetic material is subtracted not added by mutation.

Actually, it's more like arguing with them that since you think that flamingos were created blue so they can fly why weren’t all organisms created blue so that they can fly too.

Actually you could turn this argument around on the creationist. If what they are asserting is that if the arrangement found in whales is not also in other mammals then it could not have evolved because it is a superior arrangement and therefore all mammals should have evolved it, all you have to counter with is; If it is such a superior arrangement and was designed for whales, why did the creator not also endow other mammals like humans with this superior arrangement.

You should invite them to participate on a forum such as this or Ratskep. That’s a bold statement not backed up by the following assertions. This statement is false, but I don’t think it has been fully explained why yet. As far as I can find out the whale’s blowhole is connected to the trachaea which as in all mammals does connect to the esophagus. The explanation is that mammalian anatomy having the upper part of the trachaea above the esophagus and the lower part of the trachaea below the esophagus which are connected rather than bypassing each other, which is why it is possible for most mammals to choke on food, is still the arrangement in whale anatomy. However, in whales, the intersection is bridged by a structure known as the laryngeal spout or “goose beak” possibly a novel evolutionary modification of the epiglottis or other parts of the larynx in the whale lineage. In effect this extends the trachea through the gap that other mammals have between the lower and upper opening of the trachaea through the esophagus. Imagine a pipe passing through the walls of another pipe from one side to the other. This can still cause problems in whales, as if this extension tube gets displaced or constricted by food or foreign objects in the esophagus the animal can suffocate or be unable to get food past the blockage and thus starve. It’s not as if it’s a prefect “design” more of a kludge as most evolutionary innovations are. dolphins.org has a good basic explanation of dolphin evolution and also mentions the “goose beak” under the section respiratory system. That’s just a non sequitor – it does not follow from the preceding assertion even if that were true. Simply because something has evolved in one specific lineage, that of whales in this example, does not mean that this trait would have to have evolved in an earlier lineage. That is simply nonsense and would contradict evolutionary theory if it were true. Taken to its absurd conclusion every evolutionary innovation should have been effected early in evolutionary history just as soon as it was possible to do so (reductio ad absurdum is not necessarily a fallacy, it can be effectively used to make a point). Obviously if this were the case all organisms would have evolved the same adaptations therefore no divergence – no biodiversity etc. would have been possible. Evolution obviously does not proceed this way as it is a process contingent on random modifications being promoted due to their effectiveness under specific environmental conditions. The argument therefore, as usual with creationist arguments, depends on a misunderstanding or deliberate misrepresentation of evolutionary theory therefore it is a straw-man argument. Well after years of arguing against creationism on the internet myself I have never heard of it before. As with all creationist assertions it is nonsense – see above. I am sure that if you wanted to follow up on your suggestion that this should be evidenced by whale embryology that it would be, as the developing embryo would, no doubt, show that development of this “goose beak” extension tube from the larynx follows on from normal mammalian developmental processes. However, I just don’t think that the research would be worth the effort as the original claim is so easily demonstrated to be false.Also the creationist would no doubt still just claim that embryology is not “proof” that the “goose beak” evolved either.

No, I just did a course there in what now feels like the in the early Eocene.

Uh oh, I thought it might be a mistake to interject in this thread. Quite, that’s why the selfish gene is such a good metaphor. Competition can be certainly said to exist between rival alleles when taken metaphorically, and yes, selfish genes compete with other selfish genes, however, they also can be said to co-operate (and still be thought of as selfish) if the outcome is their mutual replication. Obviously mutual replication cannot be said to be the case between alleles though. I’m not sure if I understand that sentence, you make it sound like some kind of gangster war but think that you may be taking the metaphor too literally. Again, I’m not sure if I understand that, but it sounds like you are conflating the evolutionary benefits of becoming a sexually reproducing organism and the potential evolutionary cost of doing so with the evolutionary mechanism of sexual selection there. Obviously sexual selection is only possible in sexually reproducing organisms, however, sexual selection itself maximizes the chances of sexually selected genes being replicated rather than halving the chances of any given gene getting through. The “twofold cost of sex” which I think that you could be alluding to relates to the evolution of two sexes in sexual reproduction only one of which bears young not the action of the mechanism of sexual selection. Or maybe you allude to the fact that only half of an individuals genes get replicated to the next generation? But that is not a problem when one considers it from the selfish genes point of view - that it is the genes in the gene pool that are being replicated and that they have no concern for which individual vehicles that they find themselves in as long as that individual is capable of reproducing and passing them on to the next generation. As long as they are frequent in the gene pool it matters not, to them, the genes, whether only half of an individuals genes get passed on to the next generation as copies exist in more than one individual in the gene pool. You could think of sexual selection as being an aberration of natural selection in sexually reproducing organisms allowing evolution to be directed along pathways unavailable to asexually reproducing organisms though. Also that this can be exploited by those selfish genes promoting traits that would not necessarily be of benefit to the organism’s survival otherwise e.g. the notorious peacock’s tail. Is that something like what you are getting at? After skimming your previous posts I am still not quite sure what this “mechanism that you are proposing” actually is. “Sexual selection genes”, “the genes defining the sexual selection mechanism” and “striving to mask familial weaknesses” are unusual choices of words but I can only guess that you are alluding to the fact that not only the genes for sexually attractive traits are being selected and passed on but also genes that promote the behavior that selects those traits are also being selected and passed on in a kind of positive feedback loop. However, natural selection for organisms that are not for example so outlandishly ornamented by sexually selected traits that they are less able to survive and pass those and other genes on is the obvious curtailer of this feedback loop. So I suppose that this is what you are getting at by the above paragraph, it’s quite hard to tell by your strange usage of words though. All I was actually commenting on was the fact that self elimination by whatever means, and the apparent altruism that this may imply, is possible because self-elimination can start to pay bigger evolutionary dividends to the genes in a given population’s gene pool by giving them a greater chance of being replicated than does the individuals continued existence is exactly what is explained by an understanding of the metaphor of the selfish gene. So, you were on the right track there. But trying to unpick your response to that comment has been an entertaining intellectual interlude, so thanks for that at least.

By george, I think you have got it - with the inserted additions.

Maybe dogs bark for humans but birds sing for themselves? dog-bark-origins The idea is that the harsh bark of a dog has been selected by humans to be a warning to humans. The "song" of a bird is selected by birds to be a warning or mating call for birds, the fact that humans find it pleasing to the ear is simply a coincidence. I would suggest that it is like the fact that we find flowers pleasing to the eye whereas flowers (wild ones at least) were selected often by insects to the benefit of both plants and insects. It just happens that our pattern seeking mental processes find the patterns that we see in flowers and hear in birdsong pleasing as a coincidence. However dogs barking is a pattern that we find displeasing and that is why it has been (maybe quite unintentionally originally) selected in dogs. Mind you, I sometimes find birdsong quite raucous myself. For example the starlings that roost in the ivy in the courtyard outside my house can make quite an annoying racket - so it is quite subjective as to whether birdsong is pleasant and melodious, anyway.