Biological fitness - What Is It? (Page 4) CoIin: And I've figured out where I went wrong with the kangaroos . It was just one teeny-weeny error - my mistake was in claiming "Jim is both more fit and less fit than Dave" is an absurd consequence. It's not absurd at all given that particular definition of fitness. If you happen to be an advocate of the (incorrect, I believe) "fitness is defined in terms of survival/reproduction" view, then Jim prevailing in one iteration, while Dave prevails in another, is NOT an absurd consequence. Jim won one and lost one. So what? On this view, fitness is analogous to "performance" (and performance here means simply winning or losing). Jim "performed" better in one iteration while Dave "performed better in the other, thus there is nothing absurd about saying Jim was more fit in the first game and less fit in the second. It's only absurd to say that Jim can be both more fit and less fit than Dave under the (correct) view that fitness is defined by physical/psychological characteristics (relative to a particular environment). If we arm-wrestle twice in a row, and the result is 1-1, it's absurd to say I was physically stronger than you the first time and weaker than you the second time, but it's not at all absurd to say I outperformed you the first time (even if that just means I got lucky) while you outperformed me the second time. So next time a silly Scotsman says to you "How can Rangers win a match in the morning and lose another in the afternoon? That's absurd! " - just say (Edited by CoIin) duncan124: Nope all wrong there. The idea has been investigated by the Australians and it was found that within a normal herd all the animals will mate regardless ' status' or health. CoIin: Another point to note... Let's say the year is 3000 AD and we superhumans have reached the stage where our prodigious, if not quite omniscient, intellectual powers DO allow us to determine which organisms are fitter with respect to a given environment without recourse to post hoc analysis of survival/reproductive success as a guide (a helpful but not infallible guide). We're now ready to face Corvin's challenge. So let's also say we DO produce evidence of a less-fit group of organisms prevailing over their more-fit conspecifics, what are we to say now? Have we taken on Corvin's challenge and emerged triumphant? Can we proudly present him with that Golden Fleece that he did not expect, and most definitely does not WANT, to see? Answer : Yes!! Have we, in the process, refuted natural selection? (Remember, this was the whole point behind Corvin issuing his challenge. He apparently felt confident that his challenge could not be met, but if it was met, natural selection may be in trouble. ) Answer : No!! To claim that the more-fit ALWAYS prevail over the less-fit is to get caught up once again in the circular quagmire of equating fitness with survival. We're supposed to have outgrown that by now, boys and girls. Darwinism, if I'm understanding CD correctly, does not preclude the less-fit prevailing over the more-fit any more than molecular theory precludes all the oxygen molecules in your room concentrating in one corner thereby precipitating your premature death by way of suffocation. IT'S JUST VERY UNLIKELY!! - especially when the number of organisms/molecules involved is large. (Edited by CoIin) duncan124: You are ' getting stupid ' as you go along. The ' law of gases ' explains why gases don't do as you have described. ChisC has pictures of fossils that he claims go from oldest to youngest and which show a jaw which goes from snug to gape and then back to a more fit design. The mechanical advantage is lost by ' natural selection ' it appears. CoIin: Monday morning musings... The analogy I drew above between the less fit prevailing over the more fit and the oxygen molecules in a room clustering in one corner is, I believe, qualitatively correct - there is no law prohibiting either - however it may may be quantitatively misleading. The probabilities involved would seem very different. The chances of all the oxygen molecules in your room concentrating in one corner is so vanishingly remote as to be negligible. Not so, I suspect, with survival of the unfit. After all, Darwin did emphasize that the variations (mutations) germane to natural selection would be very small. What we would expect to see in nature, then, is ever-so-slightly-more-fit organisms competing against ever-so-slightly-less-fit conspecifics. Therefore, it seems to me, we should not be at all surprised to see cases of less fit individuals, and even less fit groups of individuals, prevailing over the slightly more fit, although the overall tendency will be "survival of the fitter". Here's the best analogy I've been able to think of so far. Imagine Mega Casino in Las Vegas which has one million blackjack tables. The rules of the game favor the house, of course, but if a punter plays sensibly ( "fight/flight appropriate" ), perhaps according to a fixed protocol, she is only at a very slight disadvantage. Her expected return on a $1 bet might be $0.99. We all know what winners and losers are. Winners are those who end up with more money than they started with and vice versa for losers. Both players and dealers can be winners or losers. But now let's say we want to introduce a notion of "blackjack fitness" (BF). How are we to understand this notion? Option 1. We could define BF simply in terms of monetary gain. Now, if this is the case, the only way we can know who is relatively fit is to wait until the evening is over and see how much they've won or lost. This is all it means to be fit. To be fit is to be a winner and we can't know who the winners are until the fat lady has sung. All other things being equal, if Bill ends up with more money than Mary then Bill is fitter than Mary. We'd have to wonder, though, what was the point of introducing the term BF? How does this add to our understanding? To be BF just is to win. It makes absolutely no sense to say "Alan won because he was fit". His BF does not explain his winnings; his blackjack fitness JUST IS his winnings. The term is completely devoid of explanatory power. It tells us that the fit and the winners are one and the same, but it tells us nothing about WHY some people win and others lose. This would be like choosing another word for "dog" when we already have a perfectly good word. It adds nothing. Analogously, this is clearly not what Darwin meant by biological fitness. Option 2. We regard BF as the PROPENSITY to win money at blackjack - not the same thing as ACTUALLY winning money. If we were so inclined, we might wait until the casino closes and then ask everyone how they made out. This would serve as a good guide as to to who is more or less fit. But it must be emphasized that this is ONLY a guide, and by no means infallible. It's quite possible that those less fit could win money and those more fit could lose money. There is another and better way, however. We ask a mathematician to calculate the odds. Suppose he calculates that all dealers have an expected return of $1.01 on every $1 bet placed, and each player has an expected return of $0.99 (assuming she sticks to the given protocol) . We can now identify precisely who are the less fit and who are the more fit. We don't need to wait until the game is over. We don't even have to wait until the game begins. The dealers are more fit, the punters less fit, but note that the difference is slight. This, I believe, is what Darwin means by fitness. Well, let's go inside and watch the action at the tables. Should we be surprised if we see Mrs Jones making a killing, even though she is slightly less fit than her dealer? Ans : Not at all. Should we be surprised if the entire London Philharmonic Orchestra is making a killing, even though each individual member is slightly less fit than each individual dealer? Ans: well, to a certain extent. We might raise an eyebrow ( ) and you can bet the pit boss would be watching like a hawk, but there's no particular reason to suspect that our mathematician friend has miscalculated. No law has been broken. What WOULD be shocking to us is if the entire casino lost money night after night. In conclusion, it seems to me that counter-examples to Corvin's Challenge should not be particulary rare in nature. Individual cases would be common, group cases less common, and cases involving very large groups over long time periods would be very uncommon. But, as noted earlier, the barrier to meeting Corvin's challenge is epistemic. It's not that there are no counter-examples out there; it's just that we are unable to identify them. We need the equivalent of that mathematician!! (Edited by CoIin) CoIin: This "fitness" is turning out to be an extremely vexed notion. . I thought it was just me that was confused at first, but it seems many other people are too. Consider this analysis I found randomly on the Internet:- "What is fitness? Fitness is the ability of an organism to survive, and make copies of its alleles that are represented in the next generation. Organisms that produce more surviving offspring are more fit, those that produce fewer are less fit, regardless of how beautiful, strong, or interesting they are. Differences in fitness may be due to differences in survivorship, differences in fecundity, or both. Any allele that affects either or both of these will be subject to natural selection. Note, however, that there are alleles that decrease survivorship, but increase fecundity, and vice versa. An extreme example of this is the Japanese earwig, which incubates a brood of eggs that later hatch and devour her. Over millions of years, evolution has favored alleles that increased her net number of surviving offspring, even if that meant a shortened lifespan due to cannibalism." http://www.uic.edu/classes/bios/bios101/Selexio.htm It seems to me that the author is as confused as the rest of us. Look at sentence two - "Fitness is the ability of an organism to survive, and make copies of its alleles that are represented in the next generation." Absolutely correct!! (according to my own understanding at least). But it's critical that we put the emphasis on the word "ability", or call it a propensity or potential if you like. Now look at sentence three - "Organisms that produce more surviving offspring are more fit, those that produce fewer are less fit, regardless of how beautiful, strong, or interesting they are." Absolutely wrong!! (according to my understanding). The writer now contradicts himself. He's fallen into the trap that I was falling into. The fit are not necessarily the organisms that produce more offspring, but the organisms with the PROPENSITY/ABILITY/POTENTIAL to produce more offspring. (And note that by making this mistake, the writer robs the term "fitness" of all explanatory content, thus rendering the maxim "survival of the fittest" viciously circular, and plays right into the hands of Creationists and other anti-Darwinians. So there! ) Possessing an ability or a propensity to a higher degree than one's rivals (i.e. to be fitter) DOES NOT ENTAIL THAT THIS PROPENSITY WILL BE ACTUALIZED. Or, put another way, "having what it takes to succeed" and "succeeding" are not the same thing. This thread has turned out to be very helpful to me. My notions of "fitness" had been very vague previously. They're not any more. I would now be in a very strong position, I think, to defend Darwinism against allegations of circularity. Bring it on, dah-lin (Edited by CoIin) duncan124: As I said... you seem to have misunderstood that the law of gases explains why gases dont behave as you have described,.. but as that is school science I am wondering what you long posts are exactly about. Casinos have understood how often people can win at Blackjack and know how to play to make money. There are troughs and high rolls which people want to avoid or play but that is exactly what real animals and plants cannot do. You might like to insure against flood, fire and third parties but it is a problem for 'Natural Selection'. If the chosen ones who were heading for the next species are wiped out as they might be in a natural disaster then that next species did not happen. Darwins evolution relies on ' gradual change ' within a group of animals or plants. (Edited by duncan124) Aura: Can I just throw a thought out here... There's an issue with measuring and defining. We measure fitness in terms of survival and offspring and that makes sense since survival and offspring are big deal in evolution. But you can't really say that those measurements define the thing you are measuring. Even 'more surviving offspring' isn't quite right, since predatory spices tend to be smaller in numbers and have fewer offspring than grazing/herbivore spices. Still one can't claim a wildebeest to be fitter than a tiger, very different survival strategies. Strange that 'fitness' gets all this attention, while 'survival' is just as vague. It certainly does not mean 'does not die'... duncan124: A natural balance in nature often means several species of plants and animals living together but not knowingly related actions by each of them is keeping the environment stable. Animals that are very fit are very active because they have to be and animals that have an abundance of food within easy reach relax and grow bigger but not fitter in any sense even if they are more likely to survive. Animals that have no problems within their environment grow far bigger then anything we are used to. Fish can grow to an astonishing size if they have quiet clean water free from bugs and plenty of food. Likewise sea birds can then grow to the size of humans almost! CoIin: Hi Aura . Glad to hear your thoughts. First of all, whenever I used the term "survival" throughout this thread, I mean survival and reproduction, i.e. survival long enough to produce offspring. It's just simpler to say "survival". Yes, of course, it doesn't simply mean "not dying". Perhaps "continuation" would be even more felicitous. But regardless of what we take survival to mean, what we have to avoid doing here (in order to escape circularity) is defining fitness in the same terms, i.e. purely in terms of "survival". Supposing we already know about a certain property - temperature (T), say - and we then introduce a new term - pog (P), say. Now if P is purely a function of T, regardless of what that relationship might be (P=T, P=2T, P=T squared, etc), then all we've done is define P into existence. P tells us nothing about how the world works. If we know what T is, then we always know what P is. (You won't win any prizes for "discovering" that 2F = 2MA ) Consider the example of, say. density. If we define density, as we do, as simply mass divided by volume, then we might be making life simpler for ourselves by just using a D instead of an M and a V, but we haven't "discovered" a new property; we've "created" one. D is simply a convenience. Mass and volume do not EXPLAIN density; density is just mass and volume expressed in a different way. You could invent a name for M x V if you liked . To say "Object X is dense BECAUSE its mass is large and its volume small" is to say nothing at all. This is what we want to avoid doing with survival and fitness. We'd like to think that fitness is substantive, that it tracks something in nature, and is not simply survival wearing a different hat. We want to be able to say meaningfully "Certain organisms survive(d) BECAUSE they are fit". So, if by "measuring" you mean "see how well they survived/reproduced/thrived" then that's fine as long we understand that this is only a guide to fitness. What we don't want to do, as I think you hinted, is DEFINE fitness purely in these terms. As for wildebeest and tigers, I agree. Fitness, I think, should be a relative concept - relative to a given environment - and we can only say A is fitter than B if A and B are (at least potentially) in competition.. To push my casino analogy from above, fitness at blackjack would not translate into fitness at poker. Wildebeest and tigers are playing different games. It would be meaningful to say Tiger Woods is a fitter golfer than, um, Joe Bloggs (I don't know any other golfers ) but I don't think it would be meaningful to compare the fitness of a golfer to that of a tennis player. And note that what we must not do is define "good golfer" (= fit golfer) purely in terms of competitions won, lest we fall back into circularity. A good golfer would be assessed in terms of driving skill, putting skill, equanimity under stress, and countless other factors, perhaps not all articulable. A partial definition is just fine. A partial definition leaves the door open for revision as we learn more. We're never going to learn anything more about density. Finally, something to think about - consider our notions of "intelligence". As with fitness, most of us seem to feel that there really is such a thing, that our talk of intelligence actually does track something real in nature, even if we can't pinpoint exactly what it amounts to. Analogously to my interpretation of fitness, what we DON'T want to do is "identify" intelligence (fitness) with the results of an IQ test (survival). We might hope that IQ test results REFLECT intelligence, they can act as an indicator or a symptom of intelligence, but they don't DEFINE intelligence. Otherwise, if you fake it on the test, perhaps in order to impress the local hillbillies, and score 70, then I'm afraid you're dense, dah-lin - by definition. Anyway, these are just my ideas. As we can see from the links I've posted, this is by no means a clear cut issue. I always wish there was some omniscient professor out there that we could submit our papers to. And I'm always worried that he'd throw mine back at me and say "What a load of bollocks!" ) (Edited by CoIin) CoIin: Vindication!!!!!!!!!!!!!!!!!!!!!!!!!!! This is EXACTLY what I've been getting at Anyone with an interest in the content of this thread will LOVE this http://mechanism.ucsd.edu/teaching/philbiology/readings/mills.beatty.propensity.1979.pdf In particular, here's a juicy sample... "Fortunately, we do have grounds quite independent of the issue of explanatory circularity for deeming inadequate definitions of "fitness" in terms of actual survival and reproductive success. For, such definitions conflict with biologist's usage of the term, as is demonstrated by the following considerations. Surely two organisms which are genetically and phenotypically identical, and which inhabit the same environment, should be given the same fitness value. Yet where fitness is defined in terms of actual number of offspring left, two such organisms may receive radically different fitness values, if it happens that one of them succeeds in reproducing while the other does not. Scriven (1959) invites us to imagine a case in which two identical twins are standing together in the forest. As it happens, one of them is struck by lightning, and the other is spared. The latter goes on to reproduce while the former leaves no offspring. Surely in this case there is no difference between the two organisms which accounts for their difference in reproductive success. Yet, on the traditional definition of "fitness," the lucky twin is far fitter. Most undesirably, such a definition commits us to calling the intuitively less fit of two organisms the fitter, if it happens that this organism leaves the greater number of offspring of the two. Nor can these counterintuitive results be avoided by shifting the reference of fitness from individual organisms to groups. For, precisely as was the case with individuals, THE INTUITIVELY LESS FIT SUBGROUP OF A POPULATION MAY BY CHANCE COME TO PREDOMINATE. For example, an earthquake or forest fire may destroy individuals irrespective of any traits they possess. In such a case, we do not wish to be committed to attributing the highest fitness values to whichever subgroup is left." (my caps ) Aura: I still find it somewhat funny that the only way one can discredit survival of the fittest is by dragging in events that stand outside the mechanism of evolution. Yeah, mamals were fitter than dinosaurs because they survived a meteor impact? Never heard any respectable scientists make a claim like that though CoIin: Who's discrediting anything? The writers of the paper above (as well as myself) are DEFENDING Darwinism against allegations of circularity!! CoIin: Apparently I've been completely misunderstood. I'll try to recap as clearly as possible. If fitness is defined purely in terms of survival/reproduction then the maxim "Survival of the fittest" IS circular. It tells us absolutely nothing. It has zero explanatory power. This is not to say that, thus defined, the term "fitness" is meaningless. Rather, it is to say that fitness and survival mean the same thing. There's nothing particularly disastrous about this in and of itself. The problem is when people (lay people or even biologists themselves, as the writers point out) implicitly or explicitly accept this definition BUT THEN PROCEED TO USE THE TWO TERMS AS IF THEY MEAN SOMETHING DIFFERENT. They use one to explain the other. They might say "X survived BECAUSE it was fit." As noted above, if fitness is defined purely in terms of survival/reproduction, then one cannot explain the other. Anyone (Creationist or otherwise) who accused the biologist above of circularity WOULD BE ABSOLUTELY CORRECT. If he further claimed that the slogan "survival of the fittest" is vacuous, he would also be entirely justified. THIS IS WHAT I'VE BEEN DEFENDING DARWINISM AGAINST!!!! THIS IS WHY I'VE BEEN INSISTING THAT FITNESS MUST NOT BE DEFINED PURELY IN TERMS OF SURVIVAL AND REPRODUCTION. I've been pointing out that fitness is NOT to be construed merely as success in producing offspring. It is to be interpreted as the PROPENSITY to do so, which is not the same as ACTUALLY doing so. Thus interpreted, fitness and survival no longer mean the same thing, and the circularity evaporates. Consequently the dictum "Survival of the fittest" and a proposition such as "Group X survived because they were fit" can be viewed as synthetic, i.e. they are substantive, they make a claim about the world, as opposed to an analytic proposition like "all bachelors are unmarried" which is trivially true and devoid of content. (Edited by CoIin) CoIin: And the proposition "Draigo kicked my ass at Wordy, but I'm a better player" is also perfectly legitimate. CoIin: I'm reading through that article again right now. It's crazily uncanny I can't believe how amazingly similar the writers' ideas and proposals are to the posts I've made earlier in this thread. They even draw an analogy between fitness and intelligence as I did above!! If anyone else had written this thread, the cynic in me would assume that he read the paper above FIRST before making the thread. The fact of the matter is that I read the paper above for the first time in my life about two or three hours ago. The reader can believe whatever he/she likes. duncan124: I think St Mungos might be calling you Colin, after those few posts; not least because you have reinforced claims of ' circularity '. ' Fittest ' in terms of evolution must those be those that did survive. If on the other hand you are saying some things are more fit in body and mind but suffer more you are moving to a Christian view. The problem with Darwins Natural Selection is that it claims the choices of the animals result in new species. There is no evidence to prove Darwins claim. In fact his example of birds in trees choosing which mate has been shown to be false. If gradual change happens then it is as other Natural Philosophers had already claimed by location, and the example is cows. duncan124: To make my point clear. The fittest is not the first to breed but is the last to die. Spring follows fall and the last animals standing will be the start of the new species. duncan124: Colin is wrong here;- "I've been pointing out that fitness is NOT to be construed merely as success in producing offspring. It is to be interpreted as the PROPENSITY to do so, which is not the same as ACTUALLY doing so." He has confused fitness with Health. There is no reason to avoid the concept of health which we all know. CoIin: Ok, folks. Here's a fun game. I've been suggesting in this thread that many people, whether they know it or not, are confused over their ideas of what exactly fitness is. I certainly was before I started this thread and it's entirely possible that I still am. At the very least, no matter how we construe fitness, we must be "consistent", that is, we must not contradict ourselves. I recommend you try the following quiz on your friends, especially those interested in science or philosophy and see how they fare. If your friend ends up contradicting herself, there's clearly a problem. Here's what to do. Ask your friend the following two questions:- Q1. Consider two kangaroos in the same environment, Anne and Sarah. Anne dies without passing on her genes. Sarah has three little joeys. Which one is more fit? (If she says Sarah, in order to avoid backpedaling at a later stage, ask your friend "Are you sure? Is it possible that Anne is fitter?" And poke her a few times too ) Q2. As a thought experiment consider two organisms. They might be bacteria or they might be monkeys. Call them Amy and Sally. Amy and Sally are identical - down to the last molecule. They live in the same environment. Which one is fitter? At this point you reveal that we've been talking about the same two organisms. Amy is a nickname for Anne, and Sally is a nickname for Sarah. Let's just call them A and S from now on. Now (Q1), if your friend insisted that S is more fit, this shows that she is committed to the view that fitness is purely a matter of reproductive success. Fitness JUST IS survival under this view. (Q2) If your friend answered that A and S are equally fit (the intuitive answer), then she has contradicted herself. She first told us in Q1 that S was fitter than A. Now she tells us in Q2 that S and A are equally fit. First she told us in Q1 that fitness is purely a matter of reproductive success (physical characteristics don't matter), then she told us in Q2 that fitness is NOT purely a matter of reproductive success (physical characteristics DO matter). It can't be both. Houston, we have a problem. A more cunning biologist might give the following answers:- Q1 : Sarah is more fit. (The biologist commits herself to the view that fitness just is reproductive success) Q2 : We can't know. We'd have to wait till they die (and perhaps long after) and compare reproductive success. This clever biologist has avoided contradiction - she is consistent. The problem is that, under this view, fitness and survival are identical. "Survival of the Fittest" is circular and vacuous. And there is always the risk that she will forget she is committed to the position that fitness and survival are the same thing, and fall into the trap of using one to explain the other. She CANNOT now say, for example, that organisms survive BECAUSE they are fit. Now, here is what both myself and the writers of the Mills/Beatty paper above would answer:- Q1 : We can't know for sure. The fact that S produced three offspring while A produced none is suggestive that S is fitter but not conclusive. Q2 : They are equally fit. Fitness thus construed avoids inconsistency, i.e. we don't end up contradicting ourselves ( ) and "fitness" can be used as a substantive term in its own right. It is not simply survival. It can EXPLAIN survival. (Edited by CoIin) duncan124: I don't think Colin understands the question. Clearly at one time questions about evolution lead to a situation where the environment was factored in and this lead to the idea of two people both needing the same thing and thus being in competition. The nazi idea of taking from others and being the ' master race ' are, along with the UK Conservative Partys ideas ,so connected with the saying ' survival of the fittest ' and so despised that there is little left to say about it. Darwins ideas were based on brightly coloured birds choosing their mates. Colins idea fails because no animal is ill all its life, it just dies or recovers. And no species is unfit. In fact species that have extra ' capabilities' and so can produce several breeds are far better adapted to survive even if those extra capabilities are not always used and no doubt are unfit at many times. (Edited by duncan124) CoIin: Consolidation I fear that the contradiction highlighted in my post above may not be sufficiently apparent. The point is quite subtle and it's conceivable that the reader might not see the contradiction immediately, or that our friend when quizzed will even deny that she has contradicted herself. Let's remind ourselves of her answers:- Q1 : S is fitter Q2 : A and S are equally fit Well, how did our friend decide in Q1 that S is fitter? What CRITERION did she use? Clearly, the only factor she considered was a kid-count. Physical characteristics were not a consideration - she didn't even ask about them. Therefore her criterion for fitness in Q1 is transmission of genetic material, AND ONLY THIS. How about Q2 then? Well, clearly in this case, our friend's rationale is that if A and S are physically identical then they must be equally fit. But wait a minute! I thought your criterion for fitness was transmission of genetic material? You haven't even asked about that!! What we see then is that our friend's criterion for fitness has magically switched between Q1 and Q2. Now, friends and lovers, whatever criterion we finally decide upon for fitness may be a matter of some controversy. In the meantime you may have your criteria and I mine. And that's cool. But one thing I think we can agree upon is that no matter what criterion you adopt, you have to stick by it. You can't bounce from one criterion to another willy-nilly halfway through the game. This is simply not acceptable. Or in layman's terms... this is an outrage!! duncan124: I think you have to compare two very similar species, such as Darwins birds, which are now in competition for the same food etc in the same environment. Otherwise the two examples you give will just become two species Biological Fitness would include number of offspring as well as rate of reproduction; plus some kind of check to ensure numbers do not exceed food supply. CoIin: I've recently been reading a collection of essays by Australian philosopher David Stove entitled "Darwinian Fairy Tales". Here's a link:- http://maxddl.org/Creation/Darwinian%20Fairytales%20-%20Selfish%20Genes,%20Errors%20Of%20Heredity,%20And%20Other%20 Fables%20Of%20Evolution.pdf The essays are thought provoking. And a little googling will demonstrate once again, as if further demonstration was needed, the astonishing level of acrimony which any heretic daring to question Darwinian orthodoxy is likely to encounter. Sigh . Anyway, Stove's basic argument is:- Darwinism is a general theory which applies to all terrestrial species. Darwinism may well be true of other species, but it is not true of OUR species. Therefore Darwinism is false. Well, make of that what you will . But there's no need for any WireClubbers to get their knickers in a twist. Call off the Inquisition . I'm not out for blood. My only agenda is clarification, learning and the prevention of cognitive atrophy. If anyone else feels the same way, then join me in a didactic dialectic. The first essay in the book bears indirectly on our discussion of fitness above, and is quite enlightening. Let's remind ourselves first of two ways that fitness might be construed:- Fitness1 - On this view, fitness is purely a matter of reproductive success. If individual X or group X produces more offspring than individual Y or group Y, then X is fitter than Y. That's all there is to it. Recall also that under this interpretation, fitness does not and can not explain survival/reproductive success, rather fitness is "identified" with survival/reproductive success. They are the same thing. "Survival of the fittest" is thus a tautologous truism of the form "all circles are round" - it tells us nothing about the way the world works. It's also entirely unfalsifiable and therefore (on one account at least) unscientific. {Fitness1, according to Stove, is the current orthodoxy in biology. He calls this interpretation of fitness "ridiculous" . You'll see why below.} Fitness2 - On this view, fitness is a matter of the physical and perhaps psychological constitution of an organism relative to a given environment. Under this interpretation, it is meaningful to suggest, as Darwin does, that fitter organisms will tend to prevail over the less fit. Numbers of offspring may provide a helpful indicator of fitness, but reproductive success is a SYMPTOM or an indicator of fitness, not its definition. {Fitness2 is our intuitive sense of fitness. Eg. I guess most of us feel that two physically identical organisms in the same environment are equally fit (contra Fitness1 which would demand a kid-count). Fitness2 is clearly how fitness was construed by Victorian gentlemen, including Darwin himself, as you'll see below. } As we've seen throughout this thread, both interpretations have been used, and are still used, by different people, both lay and professional, in different times and places. We've even noted that the confusion is such that a given individual may bounce between interpretations in mid-conversation (see my quiz above) without even being aware. Now, getting back to Stove, his coverage of the nascent eugenics movement in late 19th century Britain offers a telling vignette into the fitness imbroglio. You'll find the relevant sections in pages 8-11 of his opening essay "Darwinism's Dilemma". The upper echelons of society were worried... "By about 1880 Galton [Darwin's cousin] had become convinced, and had begun convincing others, that some eugenic measures - or what might now be called measures of 'quality control in humans' - were absolutely imperative for Britain. The eugenists leave us in no doubt as to why they thought this. It was because, in late 19th century Britain, the fittest people were visibly not outbreeding the less fit. In fact the boot was on the other foot. The overwhelming tide of philanthropic and egalitarian sentiment had brought about a population in which there was, (as several writers put it at the time), a preferential 'survival of the unfittest'. That is, a preferential rate of reproduction by the indolent, the improvident, the unintelligent, the dishonest, the constitutionally weak, the carriers of hereditary disease, the racially inferior, and so on." Well, well, well . We've come full circle in the thread. This IS Corvin's challenge! Galton and his buddies apparently were convinced that they were witnessing just what Corvin and Darwin claim isn't supposed to happen - the less fit prevailing over the more fit! Here, then, is the Darwinian "hard man"s dilemma. What to do? Option 1 - Concede that Darwinism is false. The more fit do NOT always prevail. Our species proves it. Option 2a - Maintain that Darwinism is true and adopt Fitness1. That is to say, sorry Mr Galton et al, these scrawny, lazy, stupid, sickly criminals by virtue of producing more l'il nippers than you and your fine friends are IPSO FACTO more fit. So there! While this would salvage Darwinism from logical collapse (it amounts to taking refuge in a tautology), clearly this was not an option for these guys. What we see, then, is that in Victorian England, as opposed to the present day, Finess2 was the standard interpretation of fitness. As Stove makes evident, the adoption of Fitness1 was never seriously considered:- "Strictly speaking, there was one other conclusion which Darwinians could have drawn from the demographic facts which terrified them: namely, that the mentally defective, the carriers of hereditary disease, and so on, actually were fitter than the average upper middle class Britons. But this would have required the superior fitness of one group of organisms to another to be identified with its having a higher rate of actual reproduction: an idea which, THOUGH IT IS NEO-DARWINIAN ORTHODOXY AT THE PRESENT DAY, really is as ridiculous as Galton would have thought it. For suppose it were true, and suppose that Jack proposes to have children by Jill, though he through genetic misfortune is blind, violent, and of sub-normal intelligence, while she has inherited deafness, syphilis, and AIDS. Then even the best medical advisor could only say to these intending parents something like the following. 'It's no good asking me or anyone else whether you two are fit, or how fit you are. That can be known only after you have finished reproducing. If you manage to leave behind you more children than the average couple, that will prove you are fitter than the average couple, or rather it will be your superior fitness. But there's only one way to find out, so off you trot and get stuck into it. You could be lucky. Beethoven's father, remember, was a genetic disaster." Option 2b - Maintain that Darwinism is true and adopt Fitness2. Now, this would be a very hard position to defend. Think back to my casino analogy above. Being a statistical process, natural selection CAN allow for individual cases, and even group cases, of the less fit prevailing over the more fit, but if the less fit are continually triumphing over the more fit, Darwinism would appear to be in dire straits. What happened instead, as Stove points out, was something different and something quite contradictory. The eugenists, being staunch Darwinians, could not admit the possibility that Darwin's theory might be wrong. Neither could they accept society coming to be dominated by the "unfit". Therefore, what the eugenists were in effect saying was "These guys [the unfit] are breaking the laws of nature. We must put a stop to this!". It seems they felt the laws of nature needed a helping hand If it is indeed a law of biology that, in ALL species, natural selection will see to it that the fit prevail over the unfit, WHAT ON EARTH WERE THEY WORRIED ABOUT? How can a law of nature be broken? If it can be broken then it's not a law . Or with the benefit of Stove's mordant wit:- "Galton's intellectual and emotional situation was therefore this. On the one hand there was Darwin's theory of evolution. If it is true, then competition for survival is always going on in every species, and as a result natural selection is always going on too. Therefore, preferential survival of the organisms best fitted to succeed in the struggle for life is inevitable. But on the other hand there were, right before his eyes, the quite opposite demographic realities of contemporary Britain. What could poor Galton possibly be expected to conclude, except that the inevitable was being led astray, and needed the help of people like himself in order to be put back on the rails? " and... "For they [the Darwinian hard men] combine, in about equal proportions, suggestions that man is inevitably subject to natural selection, and suggestions that we will have to be right on our toes to make sure he stays that way." If you can figure out the logic in that, you're a fitter man than I. (Edited by CoIin) | Science Chat Room 5 People Chatting Similar Conversations |