Falsification theory of Natural Selection

Hi Syamasu,I'm not sure the version of evolution by rm&ns you are arguing against is the main one used by evolutionary biology, although it does contain some of the same elements. I don't see the main elements of standard natural selection in your comparison.Darwinian natural selection refers to the action of environmental factors (the selection) on the chances of reproduction of a particular genotype (the unique set of alleles posessed by an individual organism). As such, selection operates only on the level of the individual organism. Now obviously, the organism's "environment" includes other members of the same population/species, but it is by no means limited to this. When biologists talk about the fitness or "success" of an organism, they are referring to the survival of the individual to the point where it can pass on its genetic heritage. To use your white moth-on-white-tree example: that moth may have the best adaptation in the world, but if it gets eaten before it reproduces, it has been "selected against". Its entire genotype - the sum of its genetic heritage - is gone.What you appear to be describing as natural selection above actually more resembles "evolution" itself - the end result at the population/species level of natural selection operating at the individual level. In other words, what you seem to be describing is the change in the distribution of expressed alleles (phenotype) over time within a population. This is NOT natural selection. Natural selection is one of the mechanisms of the change. Natural selection doesn't necessarily favor one individual or phenotype over another as you stated here: "meaning of selection" = "for one individual to reproduce and the other individual not to reproduce". Natural selection is not a zero sum game.Perhaps a recap may be in order. Natural selection follows from these basic assumptions:1. There must be heritable variation for some trait. Examples: beak size, color pattern, thickness of skin, fleetness, visual acuity.2. There must be differential survival probability associated with the possession of that trait.The result is that over time the population of each generation will consist of a higher proportion of individuals that possess whatever adaptation enabled their parents to survive and reproduce. If individuals having certain genes are better able to produce mature offspring than those without them, the frequency of those genes will increase. It does not imply competition, except metaphorically.Consider a population of horses which has an equilibrium frequency of allele A (for soft enamaled teeth), and allele A' (for hard enameled teeth). Both types of teeth work well in the current environment (soft, low-silica C3 grasses). What happens when the environment changes? Say, a climate change favoring hardier C4 grasses (with higher silica content). The distribution of grasses will change, with a much greater resultant frequency of C4. The horses with A alleles will have their teeth wear down much faster, and hence live less long, producing less offspring. Over time, the frequency of A' alleles in the population will increase because of natural selection. There's no "competition" between horses per se, merely differential survival in the particular environment.I hope this makes some sense in light of what you are arguing.http://207.36.64.70/ubb/smilies/wink.gif[/IMG]

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[This message has been edited by Quetzal, 05-28-2002]

Okay Syamasu. I give up. I honestly have no idea what you're arguing about. I'm sorry you consider the description/definition of natural selection I gave - the one used by every practicing evolutionary biologist, botanist, and ecologist - as "unscientific". I'm afraid I can't give you a better one. Enjoy your discussion.

Peter: Great post. Just a quick note:

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Originally posted by Peter:

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I'm not entirely sure it would be deemed Natural Selection when
one is considering the competition of two species within the
same environmental niche.

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Interspecific competition is one of the environmental factors that is encompassed by the term "selection pressures", so it's part and parcel of natural selection. There are a lot of examples, especially when you look at coevolutionary relationships like predator-prey "arms races", mutualistic or symbiotic relationships, etc. "Allelic covariance" (or sometimes "codependency" or "codependent alleles") is the technical term (which can also apply within an individual organism when you consider coevolution of carnivore teeth with carnivore digestive systems, etc).[edited to add: We also see it in the mosaic (source-sink) distribution of populations of a given organism in a particular ecosystem. In one place a particular species may be very common, in another seemingly identical patch of forest they may be very rare or nonexistent. The explanation for this pattern is niche competition with other species. The obvious corollary is that any heritable advantage over its competitor accruing to a particular individual in a given niche will obviously increase its survival chances by allowing it to exploit more resources.]

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[This message has been edited by Quetzal, 05-29-2002]

[QUOTE]Originally posted by Syamsu:
[b]The definition is in the talk.origins faq, and in this very thread Quetzal (message 11) says it also, and even you yourself say it more or less. The unit of selection is the individual, the individual reproduces, or doesn't reproduce, to be selected in means to reproduce, to be selected out means not to reproduce.[/QUOTE][/b]What is it about my writing that both Syamasu and Philip continually misunderstand me? Am I THAT incoherent? Have I posted something that isn't orthodox? Or am I simply expressing myself badly? Peter? Schraf, Dr. T? Anyone?Syamasu: From post #11 you cited in reference:

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Originally posted by Quetzal:

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1. There must be heritable variation for some trait. Examples: beak size, color pattern, thickness of skin, fleetness, visual acuity.

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2. There must be differential SURVIVAL probability associated with the possession of that trait.

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The result is that over time the population of each generation will consist of a higher proportion of individuals that possess whatever adaptation enabled their parents to SURVIVE and reproduce. If individuals having certain genes are better able to produce mature offspring than those without them, the frequency of those genes will increase. (emphasis added)

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Even re-reading this, it sounds pretty straightforward. What do I need to change to make it clearer?

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[This message has been edited by Quetzal, 06-06-2002]

Syamasu: This is incorrect. I think Peter is right, you're still confusing the two levels we're discussing. The "unit of selection" is the individual organism. The "unit of evolution" is the population. As such, the only time reproduction enters into the equation is as the mechanism by which certain traits are transmitted from generation to generation. The two levels are related, obviously, but are not functionally the same.In asexual lineages, for instance, all other things being equal all subsequent generations will be completely identical to the parent. In the absence of selection pressures operating on the individual organism, there can be no evolution. ONLY when certain traits provide a net survival advantage - some organisms preferentially surviving to pass on their genetic heritage - can evolution occur.

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If some organism in a population dies, it's already evolution.

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Not if all the organisms in a population are genetically identical - as can occur in some asexual lineages (for example pure lab strains of bacteria). In this instance, the death of one - or a million - individuals has no evolutionary effect because it doesn't effect the gene pool of the population as a whole - they're all identical.

Percy: I've gone back over this thread now a couple of times in order to try and puzzle out where the difficulty lies. I have read both my and Peter's responses to Syamasu, and have come to the conclusion that there is no functional difference between our explanations. Part of the problem, no doubt, is that both Peter and I have tried unsuccessfully to explain NS at least half-a-dozen different ways each in an effort to get through to Syamasu. The ONLY difference of opinion we touched on was from Peter's message 14,

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Originally posted by Peter:

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I'm not entirely sure it would be deemed Natural Selection when
one is considering the competition of two species within the
same environmental niche.

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I pointed out in a subsequent post that interspecific competition is one of the selection pressures on an organism and hence part and parcel of NS. That is the ONLY difference (besides approach) between our attempts at description.In the face of Syamasu's continued misunderstanding, and my seeming inability to make things clear to him, I don't see the utility in continuing this discussion. Sorry. I appreciate your efforts.

Percy: I don't have any problem with the "definition" in your glossary. It's the description of the process that Syamasu seems to be getting wrapped around the axle about.As far as book definitions go, it depends on who you ask. Donald Levin: U Texas: differential reproduction among differing phenotypes in a population.Ben van der Pluijm: UMich: Natural Selection is the differential reproduction of genotypes.Ernst Mayr: The process by which in every generations individuals of lower fitness are removed from a population.Hmmm, I think I'm starting to see the problem.

Syamasu: Just one (no doubt vain) note. You stated

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Darwinists ignore the weather and other environmental factors simply by not mentioning them.

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This is incorrect. Evolutionary biologists, botanists, ecologists, etc, do not ignore the weather or other environmental factors when discussing evolution. On the contrary, all of those factors are subsumed in the very definition of "environment". Usually, the term is taken to mean something like "all biotic and abiotic factors that effect the organism". This includes weather, diurnal temperature differentials, rainfall, climate, topography, vulcanism, earthquakes, etc etc, as well as all the biological factors impinging on the organism.They may not mention all the factors every time they talk about an organism, population, ecosystem, etc, because these factors are included in the definition of environment.Apologies that scientists don't always spell out every single detail. Sometimes you just have to accept that they know whereof they speak.

If I understand what you're asking - which isn't necessarily the case - you want a description of all environmental factors operating on a specific organism? If so, are you asking for a "general rule" that applies in all cases? Or are you asking for a case-by-case study?

I can't add anything to what Peter said in post #74. It appears here that all you're asking for is a name change. I don't really see the point.

Syamasu: You are incorrect concerning Mendel.

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Mendel wrote a professional and formalized piece, about the same time as Darwin.

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Mendel's Versuche ber Pflanzen-Hybride was published as a small book in 1865 - 6 years after Origin. It was incorporated into volume 4 of the records of the Association for Natural Research in Brno in 1866. The book he first published - in some 40 copies only - was distributed to well-known botanists. The only one to respond to him was Carl Wilhelm von Ngeli, who basically told him his work was incomplete. In essence, no one at the time - botanists all - really understood his work. Nobody before him had ever attempted to use mathematical and statistical analysis as a means of interpreting the results of biological inquiry. It was the fortuitous rediscovery of his work in 1900 by Carl Correns in Germany, Hugo de Vries in the Netherlands and Erich von Tschermak-Seysenegg in Austria that brought Mendel to world attention. More importantly, these three men realized that that Mendel had not merely conducted experiments in successful hybridisation - which was why his work had been pretty much ignored as not being significant - but had in fact studied the heredity of specific characteristics as they were passed on from parent plants to their offspring. Up to that point, no one had realized what Mendel had done! It's only with hindsight we can justifiably claim that Mendel was the father of a whole new science: genetics.There was no suppression by "Darwinists" of Mendel's very obscure work published in a very obscure book in a small town in Austria. Or at least there's no evidence of such. It was politely received at the time, but utterly ignored by botanists - not Darwinian naturalists.Your "Mendelian" historical revisionism is getting tiresome.[Edited to add: By the way: Correns, de Vries, and von Tschermak-Seysenegg were all Darwinian evolutionists!!!!]

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[This message has been edited by Quetzal, 06-19-2002]

[Edited to remove another weird double post.]

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[This message has been edited by Quetzal, 06-19-2002]

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Originally posted by Syamsu:
Darwinists and Mendellists were fighting so heavily, so that the magazine Nature decided to close it's columns for Mendellians. Besides there are documented cases of Darwinists "disproving" Mendels theory. You are porting the politically contrived Darwinist version of history.

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regards,
Mohammad Nor Syamsu

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If you're talking about R.A. Fisher's claim in 1936 that Mendel fudged his results, Fisher's contention has been fairly well refuted. Hans Lamprecht, who in 1968 replicated Mendel's experiments, showed identical ratios; Franz Weiling in 1983 showed Fisher was basing his analysis on faulty statistical assumptions; in 1999 Johann Vollman ran 30 computer simulations to show Mendel's 3:1 segregation ratio was valid over 5000 offspring. I find it unlikely that any modern biologist - especially for the last 50 years - denies that individual genes (Mendel’s "factors") can not only be identified but also transferred as entities, complying with those laws whose formulation constituted Mendel’s life's work. Some of the details have been challenged - but his theory of inheritance remains fairly solid. Gee, just like Darwin...On the other hand, Mendel didn't get it completely right. Just as one for instance, he was either fortuitous in his choice of traits, conducted "pre-experiments" before choosing his traits, or for some other reason managed to select those traits that have the peculiar characteristic of not often being passed on together. At least two pairs of the traits he studied are located on different chromosomes in pea plants - but are almost never coupled. He also spent the last part of his life vainly trying to continue his hybridization experiments with the wrong plant (hawkweed (Hieracium) courtesy of von Ngeli - the botanist who convinced him to use it. Hawkweed turns out to reproduce asexually, which means the genetic information is passed only through the "matrilineal" line. The experiments were, hmmm, inconclusive.Anyway, as to your assertion concerning the journal "Nature", I'm absolutely certain you can provide a reference for your claim that they have changed their editorial policy and refused to publish scientific data, right?

Syamasu: Thanks for the link. I haven't completely absorbed the article, but most of what is written there doesn't contradict either of my two previous posts.There is, however, one glaring error in the article, which leads me to question both the knowledge base and intent of the author:

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Darwin believed in the inheritance of acquired characters...

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Darwin manifestly did NOT accept this notion. In fact, his theory of natural selection was adamantly opposed to the concept. The French biologist Lamarck is the person to whom this idea should be attributed. This isn't simply a typo - the article's author mentions it at least twice.I do agree with the author, OTOH, that Mendel was certainly attempting to show the immutability of created kinds with his experiments. This doesn't detract from his discovery of the laws of inheritance that form the basis for modern genetics, however. I wonder what he'd think today if he saw how his experiments provided the basis for a science that has pretty much completely refuted his initial premise. I think the author of that article "doth protest too much", to be honest. An example is claiming Mayr (the last living practicing biologist from that timeframe) somehow aided in the suppression of Mendel's works - even though "Systematics and the Origin of Species" didn't come out until 1942. The author doesn't really make a very good case for his contention that...

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The general acceptance of Darwin's theory of evolution and his ideas regarding variation and the inheritance of acquired characters are, in fact, the main reasons for the neglect of Mendel's work, which - in clear opposition to Darwin - pointed to an entirely different understanding of the questions involved.

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Of course, the author freely admits to being an IDist, so I suppose he feels that anything that casts doubt on Darwinian evolution is fair game, no matter how over-inflated - even the biblical "created kinds" argument and trying to turn Mendel into some kind of martyr.Please refresh my memory, Mendel being a martyr does what for your anti-natural selection argument, again?

What part of my three posts didn't you understand?

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The author says among other things, that DeVries and the others you mentioned, were not much Darwinists, but more mutationists.

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Where did the author say that? The people I mentioned were the guys that re-discovered AND PROMOTED Mendel's work. What are you talking about?

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Darwin did believe in the heritability of acquired charactersitics, as is generally known. I remember in "the Descent of Man" he talks about handwriting being an acquired characteristic that is heritable.

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Odd, I can't find a reference for that. In any event, that is manifestly NOT what the author is talking about in that essay. He's talking about lamarckian inheritance of acquired physical traits - like Mendel's pea plant traits - which is the antithesis of Darwinian natural selection. There is no way in the world that you can construe lamarckism from anything Darwin wrote.

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The rest of your post completely ignores the issue of why Mendel's theory was denied up to 72 years. You present no explanation, and this person presents a reasonable explanation.

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On the contrary, I provided several reasons. Re-read the posts. It is very obvious you have no concept of the history of science - and especially evolutionary science. You seem to be basing your entire view on a single article written by an avowed anti-Darwinian. Care to provide a few more references for your assertion?