Intelligent Design

Natural vs. unnatural selection: Consider the ceaseless yap of the lap dog and be warned

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In “Actually, the goal posts were just pulled up. Too much trouble to move…”, I linked to Jonathan Well’s comment on subtle attempts to change just what Darwinian evolution means, to avoid disconfirmation of any particular model. You know, first it’s natural selection only, then, lo and behold, group selection is allowed, then Lamarckism (inheritance of acquired characteristics), then gene swapping …

First junk DNA proved Darwin was right, then when it turned out not to be junk, you can be pretty sure, it will still prove Darwin was right. Darwinism has become a catch-all for a tired, worn-out theory, hysterically popular in the academic culture, with no real definition or foundation for why.

Anyway, Mike Flannery, author of Alfred Russel Wallace’s Theory of Intelligent Evolution, comments on my notes on the obviously unsupportable claim that artificial selection (= animal breeding) supports Darwinian evolution (natural selection acting on random mutation):

Anyone can breed a weird dog (I mean, assuming they have basic knowledge of canines).

But nature has a funnel.

There are only certain ways that dogs can really live in the wild.

For example, a greyhound can run faster than a wolf, because he doesn’t have heavy jaws – but what happens when he catches up with the prey?

Someone throws him a bag of Science Diet for Adult Working Dogs, right?

Human interventions almost always assume that we protect the life form from the normal routine of nature – otherwise there would be no reason to bother.

And nature is limited to certain routines. A wild animal that cannot feed itself will die.

But a Bassett Hound can live as long as its owner is willing to pay for advanced veterinary medicine, necessitated in part by the odd way the creature was bred.

If all the dogs in the world ran away, 50 years later, you would likely see only nature’s usual wolfhound type.

Anyway, Flannery comments,

Jonathan revealingly quotes Mirsky in his excellent piece: “As Darwin did before him, Coyne noted that the development of new breeds through artificial selection is a good model for the evolution of new species by natural selection.”

The model wasn’t good when Darwin presented it and it cannot be improved in Coyne’s re-telling. From the very beginning (even in the famous Ternate Letter of 1858), Alfred Russel Wallace pointed out, “in the domesticated animal all variations have an equal chance of continuance; and those which would decidedly render a wild animal unable to compete with its fellows and continue its existence are no disadvantage whatever in a state of domesticity. Our quickly fattening pigs, short-legged sheep, pouter pigeons, and poodle dogs could never have come into existence in a state of nature, because the very first step towards such inferior forms would have led to the rapid extinction of the race; still less could they now exist in competition with their wild allies. The great speed but slight endurance of the race horse, the unwieldy strength of the ploughman’s team, would both be useless in a state of nature.

If turned wild on the pampas, such animals would probably soon become extinct, or under favourable circumstances might each lose those extreme qualities which would never be called into action, and in a few generations would revert to a common type, which must be that in which the various powers and faculties are so proportioned to each other as to be best adapted to procure food and secure safety,–that in which by the full exercise of every part of his organization the animal can alone continue to live. Domestic varieties, when turned wild, must return to something near the type of the original wild stock, or become altogether extinct.” Wallace never would agree with Darwin on this point and it would lead to other more significant disagreements later.

Besides, AT BEST all domestic breeding examples merely established one thing: GUIDED and DIRECTED variation.

Maybe I am a Wallacist?

47 Replies to “Natural vs. unnatural selection: Consider the ceaseless yap of the lap dog and be warned

  1. 1
    Nakashima says:

    Mrs. O’Leary,

    Is it possible to clarify which words are Wells’ and which words are yours? I remember in another post that you said it was hard to maintain proper indents. Here you seem to be quoting two large blocks of Wells’ text, but in a different order than in his original text.

    Here on UD, I always try to use the <cite> tag instead of blockquote, q, or i.

  2. 2
    Learned Hand says:

    Darwinian evolution (random mutation acting on natural selection)

    I think that you transposed those terms.

    More substantively, I don’t follow the logic behind this argument. Granting that organisms selected for commercial viability would be poorly adapted to life in the wild, they still reflect the transformative power of gradual shifts in allele frequency over time. I don’t see any connection between the observation that domesticated specimens would die out in the wild or be forced to revert to a better adapted state, and the conclusion that you seem to be implying.

  3. 3
    jlid says:

    Learned Hand,

    The illustration demonstrates that natural selection seems to act as a stabilizing force in nature. Instead of leading to a variety of organisms, it instead restricts variety. All of the different variations (artificially introduced) get snuffed out, not furthered.

    In other words, when humans introduce changes to a species, natural selection quickly cancels those changes out; why should we expect naturally occurring changes to be any different?

  4. 4
    O'Leary says:

    Nakashima, thanks for the quote suggestion. Seems to work better at WordPress. Don’t know if it works at Blogger, will try, but Blogger always just indents everything you want with block quote.

    Learned Hand, I will corrrect the tansposition error you mentioned.

    The point is that merely producing exotic variations and protecting them is not duplicating natural selection, which does not deal in exotic, protected variations, but only in traits adapted to survival in a given environment without any protection.

    That usually means that only a few forms of a given species would really live. Producing hundreds of forms and then protecting them from natural outcomes does not produce evidence of what occurs in nature.

  5. 5
    Learned Hand says:

    jlid, I don’t see how the illustration supports the conclusion. Domesticated organisms are selected for their commercial viability, not their viability in the wild. Such specialized organisms would probably not fare well under naturally selective pressures in the wild. I don’t see how that tells us anything other than that traits derived from one set of selective pressures (value to humans) are inefficient under a different set of pressures (natural selection in the wild).

    The argument you’re trying to make would be supported by an observation that natural selection punishes all diversity. All this illustration shows is that organisms shaped by one selective environment fare poorly when the selective criteria change drastically and suddenly. I don’t think the observation is logically connected to your conclusions.

    Similarly, Denyse, you argue that artificial selection is inherently different from natural selection. The only difference I see, though, is the substitution of one set of selective criteria for another. In both circumstances, inheritable traits are subjected to selective pressures, resulting in a change in allele frequencies in successive generations. The results of one set of selective criteria may be poorly adapted for the other set: a chihuahua is no better adapted for the veldt than a lion is for the sitting room. Neither will be permitted to reproduce under the governing set of selection pressures.

    I don’t see, however, the substantive distinguishing factors you seem to assume exists between the two sets.

  6. 6
    herb says:

    For example, a greyhound can run faster than a wolf, because he doesn’t have heavy jaws – but what happens when he catches up with the prey?

    Someone throws him a bag of Science Diet for Adult Working Dogs, right?

    Unless it has that myostatin mutation like Wendy the Whippet LOL.

    But seriously, those greyhounds look so dainty, I wouldn’t count on one being able to dispatch anything larger than a fieldmouse.

  7. 7
    mivart says:

    @ 6

    You’ve obviously never heard of hare coursing. Greyhounds are perfectly capable of taking down prey (and thus surviving in the wild despite what Michael Flannery thinks). See here.

  8. 8
    Matteo says:

    Extrapolating from artificial selection to natural selection by saying “if men can do this in a few centuries, just think what nature can do in millions of years!” has always been wholly invalid.

    Intelligent causation is tremendously more potent than unguided causation. For example, a human being can get a randomized pack of playing cards into suit and number order in a couple of minutes. It can be easily shown via elementary probability calculation that the age of the universe would be insufficient for a blind card shuffling machine to be expected to get the deck into that order, even at one shuffle per second.

    So the general principle that unguided nature has powers greater than intelligent causation simply does not hold as a general principle.

  9. 9
    Matteo says:

    Another fallacy that I’ve seen a few times regarding dog breeding, a fallacy which Dawkins scathingly employed in a review of Behe’s latest book, is that dog breeding shows that there is all sorts of malleability and that it is easy to transform different breeds into each other, and that therefore this establishes the existence of unlimited evolutionary potential.

    One time I asked an unguided evolutionist, “Yes it is certainly possible to start with Arctic Wolves and, via breeding, get to Chihuahuas, but are you saying that I could start with nothing but Chihuahuas and eventually obtain Arctic Wolves?”

    The point being that by the time you reach the Chihuahua, you’ve thrown out just about all of the potential variability inherent in the genome of the Arctic Wolf. The Chihuahua has been bred so intensely, that the full Arctic Wolf genetic complement just isn’t there anymore, and you aren’t going to get it back by just crossing Chihuahuas.

    However, the answer of the unguided evolutionist was, “You’re an idiot.”

  10. 10
    Granville Sewell says:

    No one has even mentioned the most important difference between dog breeding and Darwin’s mechanism. Breeders don’t rely on mutations, ie, accidents, they select traits already present in the gene pool.

  11. 11
    nullasalus says:

    A point I would bring up is this: If we’re going to assume that, for all practical purposes, natural selection and artificial selection are operationally the same… then how do we know natural selection is natural selection? We know artificial (guided) selection exists – that much is indisputable. The existence of unguided selection is at best an unverifiable proposition, an assumption. But since it’s an assumption which can’t be verified – and since, as we hear, for all practical purposes artificial selection is the same as natural selection anyway – we can simply consider all we see in nature to be artificial selection.

    Right?

  12. 12
    Granville Sewell says:

    Of course I should have said (comment #10) the “neo-Darwinist” mechanism, since Darwin himself didn’t know about mutations.

  13. 13
    herb says:

    nullasalus:

    The existence of unguided selection is at best an unverifiable proposition, an assumption.

    That’s a very interesting point, and one which I’ve thought about a bit. Take the example of a bee which pollinates a certain type of flower. That bee is performing artificial selection just as surely as the humans who bred the greyhound. And reciprocally, the plant which produced the flower is performing artificial selection on the bee population as well.

    Hence there really is no “natural” selection, in spite of what evolutionists say. And of course no natural selection => no Darwinism.

  14. 14
    Tajimas D says:

    …subtle attempts to change just what Darwinian evolution means…group selection is allowed, then Lamarckism (inheritance of acquired characteristics), then gene swapping…

    Darwin accepted and promoted the first two in this list. He of course had no way of knowing about the third.

    May I humbly suggest that you acquaint yourself with what “Darwinian evolution” means before you attempt to criticize it?

  15. 15
    nullasalus says:

    herb,

    An interesting thought, and absolutely I think there are some interesting ideas that pop up if we argue that living organisms in general “select” things. My view of it was on a larger level – where a designer uses evolution towards certain goals and final causes, depending on the level we’re considering.

    As you said, evolution without natural selection (or with a kind of “selection” that’s metaphysically very distinct from what Darwin envisioned) is possible. And it’s still evolution – just not the evolution Darwin described. Maybe closer to Wallace’s view.

  16. 16
    Avonwatches says:

    @10 and others. The variation in dog breeds is due to a combination of phenotype selection (normal variation in physical characteristics of animals) and also Darwinian mutation (degrading mutations).

    I actually think dog breeds are an excellent example of Darwinian evolution. Of course it is directed by breeders – but pay attention to the mechanism by which diversity is accomplished!

    Every single breed has its own share of heritable illness, genetic deficiencies or predispositions. Collies, Shelties, and their crosses easily succumb to Avermectin toxicity, whereas other breeds are alright with it – these two breeds are missing an enzyme or something to deal with the drug. St. Bernards have hyperthyroidism. Boxers cannot handle Acepromazine (a sedative drug) as it often triggers hypotension+bradycardia+syncope in this breed. Cavalier King Charles Spaniels will be affected by mitral valve disease given a long enough life.

    Why is it that every breed has a particular weakness or predisposition? Because they’re missing certain elements in their body needed to deal with that circumstance.

    You find me a breed without a single predisposition or heritable illness and then we’ll talk about the wonders of Darwinian evolution! Cause all it appears to be doing is destroying existing systems.

  17. 17
    Learned Hand says:

    If we’re going to assume that, for all practical purposes, natural selection and artificial selection are operationally the same… then how do we know natural selection is natural selection?

    Is there any biology text or authority that has ever suggested that evolution will result in perfect forms? I cannot imagine any modern biologist ascribing to such a bizarre view.

  18. 18
    herb says:

    Avonwatches,

    You find me a breed without a single predisposition or heritable illness and then we’ll talk about the wonders of Darwinian evolution! Cause all it appears to be doing is destroying existing systems.

    I recently read the same thing is happening to racehorses. This article states that 2/3 of thoroughbreds are too fragile to race, and of those that do end up racing, many die due to injuries.

  19. 19
    Graham says:

    I agree with Learned hand (#2).
    Whats the point ?

    Ok, so artificially breeding exotic dogs results in dogs that have genetic weaknesses, and are probably unsuitable for survival in the wild. So what ? Is this unexpected ? It appears to be exactly what we would expect, and it doesnt seem to tell us anything interesting about Evolution, except, perhaps, that species can change when subjected to genetic pressure.

  20. 20
    nullasalus says:

    #17,

    “Perfect forms” are no more a required result of artificial selection (much less teleology, which sounds like the aim of your criticism) than “utterly useless forms” are a required result of natural selection.

    I’d neither ask nor expect such discussions to end up in a biology textbook. It’s rather superfluous to science and not justified by the data (just as assertions that evolution is devoid of any guidance, etc are.)

  21. 21
    Avonwatches says:

    @18. Yes, horse breeds suffer the same fate as dog breeds at the hands of Darwinian evolution. That goes for cat breeds too (or any ‘breed’ of species).

    This is not just Thoroughbreds, but all horse breeds. Many breed lines of Arab foals for instance are often affected by Juvenile Idiopathic Epilepsy, though transient. But no other horse breeds are affected by this.

    It is important to note that some of the physical deficiencies in our horses/dogs/etc are due to over-selection of alleles that should not be expressed as highly as we make them. The small hooves of Quarter Horses are a good example (predisposed to Navicular syndrome), which is not due to Darwinian mutation but rather human selected.

    Another thing to note is that many of the flaws introduced by Darwinian mutation might escape our watch, as they are not in critical areas. For instance, Great Dane dogs are predisposed to Demodecosis due to a T-cell problem in many breed lines, but despite this the host (dog) might not suffer any ill effects, its immune system still being able to keep the natural flora (Demodex) in check.

    Dog breeds, horse breeds, etc, are not a good indicator of the Darwinian mechanisms ‘power’ to create.

  22. 22
    Avonwatches says:

    @19. I agree with you in that respect, but I think you should look at what the Darwinian mechanism is producing (degrading mutations).

    (I have spread some examples in post #16 & also #21).

    Dog/horse/cat breeds are important examples of the true nature of the Darwinian mechanism, data we can study in the present to witness its effects.

    I think the observation of the Darwinian mechanism in dog (etc) breeds correlates well from what we have learned in Lenski’s experiment and also Behe’s work.

  23. 23
    Mark Frank says:

    Which are more successful – chihuahas or wolves?

    Dogs are an evolutionary success story. With some exceptions (working dogs), they are parasites – diverting our maternal and paternal instincts to put resources into bringing up their young with little benefit to our fitness. Like many parasites they can still succeed with fundamental weaknesses which are compensated for by their host.

    PS I am a dog lover and owner – but that is not relevant.

  24. 24
    Avonwatches says:

    @23.

    Actually if you are a dog lover & owner (as am I) then I’d call the dog-human relation symbiotic rather than parasitic. If it truly were parasitic then we would gain nothing and simply be leeched of resources. As it is (I cannot comment on what benefits your dogs provide) my dogs provide security (Great Danes) and companionship… and also bark at my horses. Hence symbiotic.

    If we are to consider dogs an ‘evolutionary success story’, then I would also label any human with a handicap or congenital disease as an ‘evolutionary success story’, on the same grounds as you do dogs. Without getting emotive, rewrite your paragraph but insert “Down-Syndrome” instead of dogs. I think we can agree that the logic is the same – if anything deviates from normal, then it is a “successful evolution story”. Nevermind *what* the actual evolution involved…

    However, delve into the details and we see the non-powers of Darwinian evolution. Yes “evolution” has occurred. But notice the deficits it leaves in every breed (see post #16 for a fuller explanation). Examining animal breeds shows how Darwinian evolution’s “success stories” involve breaking stuff into bits, not building it up.

  25. 25
    Mark Frank says:

    Avonwatches

    You are demonstrating a spectacular lack of understanding of evolutionary theory.

    Evolutionary success is measured on just one criterion – ability to leave viable progeny. If your dogs help you leave more children then it is symbiotic – but most dogs have little effect on human fecundity and may even lower it by lowering our desire to have more children. Meanwhile we make a massive contribution to their fitness.

    Any benefits they bring to us as individuals in terms of security, companionship etc are irrelevant.

    The logic is very different for Down’s syndrome. People with Down’s are almost infertile. We help them to live longer, which on a personal level is great but we don’t help them breed.

    Artificial selection is not only a good model for natural selection – it is actually a subset of natural selection. It is the environment in which some species find themselves and have adapted and flourished.

  26. 26
    Nakashima says:

    Dr Sewell,

    i think it could be argued that gene duplication and recombination are the major drivers of evolution, not random mutation. While mutation affects one in every billion base pairs, recombination brings many genes together with new variants.

    This would apply, not just to the breeding of animals, but also to viruses like swine flu.

  27. 27
    Nakashima says:

    The problems of inbred types of animals are important lessons about small populations, similar to geographically isolated populations in the wild. They can go extinct due to lack of genetic diversity.

    This does not change the validity of the lesson that artificial selection is as much an evolutionary process as natural selection, or that it is unsurprising that Darwin chose it to motivate his argument with people who would be familiar with it.

  28. 28
    ScottAndrews says:

    Mark Frank:

    most dogs have little effect on human fecundity and may even lower it by lowering our desire to have more children.

    Not tonight, honey, we have puppies.

    Artificial selection is not only a good model for natural selection – it is actually a subset of natural selection. It is the environment in which some species find themselves and have adapted and flourished.

    Dogs exist in their varying breeds because they were bred – no other reason.
    The only way their breeding could be attributable to natural selection would be if dogs lacked the “ability” to be bred and then naturally developed it so that one day it might lead to their domestication. Neither appears to be the case.

  29. 29
    Avonwatches says:

    @25. (to quote KairoFocus…)

    Onlookers. Notice how Mark Frank does not address anything to do with the details of the Darwinian mechanism in action (as I have been highlighting in every post on this thread), and rather picks at the surface issue of survival.

    Micro-evolution (dog breeds, bacterial resistance, etc) is well demonstrated. Nobody’s arguing with that.

    But look at how that tiny evolution is achieved. How can we expect macro-evolution to be accomplished with Darwinian mechanisms when all it seems to be doing is hacking off pieces of existing systems?

    Please re-read #24. I explicitly state that “yes evolution has occurred. But notice the deficits…”. Try to grasp the implication of what this means when the Darwinian mechanism is tasked with building a system.

    I would also point out that you misunderstand biology. The terms “symbiote”, “parasite”, etc have nothing to do with evolution. They simply describe the relationship between multiple organisms; that is, ‘what is’. All you are trying to do is tie evolution into terminology which functions quite well without mentioning it (which renders the rest of your points invalid, since the study of host/parasite relationships is not predicated on evolution, simply what we see in the present). :/

  30. 30
    Mark Frank says:

    #29

    Avonwatches

    I am not going to argue about the definition of parasitism or symbiosis. Anyone can look them up on Wikipedia.

    The point is that dogs are far more successful than wolves and that has happened because they have developed heritable variation which increases their fitness in their environment. Denyse was (I think – she is not the clearest of writers) trying to argue artificial selection was unlike natural selection because dogs could not compete with wolves in the wild. Well a tape worm would find it seriously difficult to compete with an earth worm in a garden. We are the dog’s environment.

  31. 31
    ScottAndrews says:

    Mark Frank @30:
    The food and medicine we give domestic dogs have nothing to do with any variation on their part. Take those away and we’ll see how adapted our pets are. (I realize I’ve just circled back to the the original post.)
    Adaptation has nothing to do with it. Feed one wolf and starve another – one lives, one dies.

  32. 32
    Avonwatches says:

    @30. I call your “Wikipedia” reference, and raise you a medical dictionary reference (Blakiston’s Pocket Medical Dictionary 3rd Edition):

    Symbiosis: A more or less intimate association or union between organisms of different species. In the restricted sense of the term, the organisms are mutually benefited and sometimes so dependant on each other that life apart is impossible.”

    Parasite: An organism that lives on or in another organism known as the host, from which it obtains nourishment during all or part of its existence.”

    Or even from Biology Online (http://www.biology-online.org/dictionary):

    Symbiosis: The relation between two different species of organisms that are interdependent; each gains benefits from the other. A relationship between different species where both of the organisms in question benefit from the presence of the other.”

    Parasite: A type of symbiosis where two (or more) organisms from different species live in close proximity to one another, in which one member depends on another for its nutrients, protection, and/or other life functions.

    The dependent member (the parasite) benefits from the relationship while the other one (the host) is harmed by it.”

    It is not within the context of evolution that we use these terms. They are descriptors for what we observe of specie-interaction.

    …and once again, look at the result of the variation = degradation of body systems. And ask yourself if this is all we’ve got (Darwinian mutation), then how was the dog “evolved” in the first place?

  33. 33
    Matteo says:

    I note that the defenders of unguided evolution are jumping in and pointing out that natural selection really isn’t the same as artificial selection, and that all the disadvantages of artificial selection don’t apply to natural selection.

    But doesn’t this just serve to undercut the case that Darwin was making when he used artificial selection to argue for natural selection? If artificial selection sux, then why use it to make the case for natural selection? Either natural selection enjoys a smooth conceptual continuity with artificial selection, thereby supporting Darwin’s argument, or natural selection is something much more mysterious, and not really supported by Darwin’s rhetorical analogies at all.

    Dawkins himself illustrates the importance of the artificial selection analogy to his case:

    link

    If mutation, rather than selection, really limited evolutionary change, this should be true for artificial no less than natural selection. Domestic breeding relies upon exactly the same pool of mutational variation as natural selection. Now, if you sought an experimental test of Behe’s theory, what would you do? You’d take a wild species, say a wolf that hunts caribou by long pursuit, and apply selection experimentally to see if you could breed, say, a dogged little wolf that chivies rabbits underground: let’s call it a Jack Russell terrier. Or how about an adorable, fluffy pet wolf called, for the sake of argument, a Pekingese? Or a heavyset, thick-coated wolf, strong enough to carry a cask of brandy, that thrives in Alpine passes and might be named after one of them, the St. Bernard? Behe has to predict that you’d wait till hell freezes over, but the necessary mutations would not be forthcoming. Your wolves would stubbornly remain unchanged. Dogs are a mathematical impossibility.

    Don’t evade the point by protesting that dog breeding is a form of intelligent design. It is (kind of), but Behe, having lost the argument over irreducible complexity, is now in his desperation making a completely different claim: that mutations are too rare to permit significant evolutionary change anyway. From Newfies to Yorkies, from Weimaraners to water spaniels, from Dalmatians to dachshunds, as I incredulously close this book I seem to hear mocking barks and deep, baying howls of derision from 500 breeds of dogs — every one descended from a timber wolf within a time frame so short as to seem, by geological standards, instantaneous.

  34. 34
    Mark Frank says:

    #33

    Matteo

    “I note that the defenders of unguided evolution are jumping in and pointing out that natural selection really isn’t the same as artificial selection, and that all the disadvantages of artificial selection don’t apply to natural selection.”

    #25 Myself

    “Artificial selection is not only a good model for natural selection – it is actually a subset of natural selection. ”

    #27 Nakashima

    “This does not change the validity of the lesson that artificial selection is as much an evolutionary process as natural selection,”

    Where did you note this behaviour by defenders of unguided evolution?

  35. 35
    Mark Frank says:

    #31 ScottAndrews

    The food and medicine we give domestic dogs have nothing to do with any variation on their part. Take those away and we’ll see how adapted our pets are. (I realize I’ve just circled back to the the original post.)
    Adaptation has nothing to do with it. Feed one wolf and starve another – one lives, one dies.

    ScottAndrews – adaptation has everything to do with it. An animal that behaved and looked like a wolf would be very lucky to get food and medicine. TO do that you need to look cute and be safe to leave with the children.

    All animals are poorly adapted when their environment is taken away. We are pet dog’s environment.

  36. 36
    ScottAndrews says:

    Mark Frank:

    ScottAndrews – adaptation has everything to do with it. An animal that behaved and looked like a wolf would be very lucky to get food and medicine. TO do that you need to look cute and be safe to leave with the children.

    Surely you’re not suggesting that wolves evolved to look cute so they could be our pets in the manner of Dances with Wolves.
    If they were bred for domestication, how can that be seen as an adaptation on their part? Being caught, put in cage with another specimen, and made to reproduce is not a demonstration of adaptability. It’s a bit like suggesting that I adapted to look like both my parents.

  37. 37
    Mark Frank says:

    Re #36

    The trouble is you cannot get your teleological model of evolution out of your mind. Wolves did not evolve to do anything. No species evolved in order to do anything. Evolution is just where the species ended up in its environment.

    The one peculiar thing about artificial selection is that individual members of the environment (us) planned the selection to some extent. But as far as the subject species was concerned that was just an aspect of the environment.

  38. 38
    Mark Frank says:

    #36 part 2.

    “If they were bred for domestication, how can that be seen as an adaptation on their part? Being caught, put in cage with another specimen, and made to reproduce is not a demonstration of adaptability. It’s a bit like suggesting that I adapted to look like both my parents.”

    The adaptation is the changes that took place as a result of being forced to reproduce. When that did not resulted in adapations that were useful to man they tended to end up as dinner (without further reproduction). Where the adaptatios were useful the species thrived as cows, dogs, sheep etc have thrived way beyond most wild mammals.

    I don’t get your last sentence at all.

  39. 39
    ScottAndrews says:

    Mark Frank:
    If we’re going to define adaptation as any genetic change for any purpose, whether those of the animal or the breeder, that’s okay. I can’t see a reason to pick on the terminology we use to describe how canines evolve into slightly different canines.

  40. 40
    magnan says:

    Mutation is the limiting factor and the primary source of variation. Recombination seems to be the basic variational mechanism exploited by plant and animal breeders. This is basically the reshuffling of existing genes. Breeding experiments have shown strict limits to how far the phenotypical modification due to recombination can progress for a given species using artificial selection. Another reason genetic recombination couldn’t be random and unlimited is because if it were, we would expect extremely high rates of birth defects and infant mortality. If recombination were the almost unlimited source of variation in addition to mutation, one would expect no such limits to be demonstrated, and nothing like the very low rates of birth defects actually observed. Instead, the injection of mutations is required to actually create the possibility of macroevolutionary innovation.

    The usual major speculated mutational mechanisms for the large differences between species are gene duplication followed by subsequent mutation, mutations in regulatory regions, and mutations in “selector genes” high in developmental heirarchies. None of these mutational mechanisms can avoid the basic complex specified information problem of macroevolution.

    The bottom line: dog breeding is irrelevant to macroevolution.

  41. 41
    Nakashima says:

    Mr Frank,

    Where did you note this behaviour by defenders of unguided evolution?

    I’m sorry, I don’t know what ‘this behaviour’ refers to in the sentence you quoted from my message @27:

    “This does not change the validity of the lesson that artificial selection is as much an evolutionary process as natural selection,”

  42. 42
    Mark Frank says:

    #34

    Nakashima

    I am sorry. My comment was not clear. I was responding to Matteo’s bizarre comment:

    “I note that the defenders of unguided evolution are jumping in and pointing out that natural selection really isn’t the same as artificial selection, and that all the disadvantages of artificial selection don’t apply to natural selection.”

    This was the behaviour I was referring to. I offered your comment #27 as a counter-example.

  43. 43
    Flannery says:

    I just looked at this thread, but this one goes to “Mivart” #7. Mivart writes, “Greyhounds are perfectly capable of taking down prey (and thus surviving in the wild despite what Michael Flannery thinks).” First of all I made no comment whatsoever about greyhounds, and in reference to natural selection, these are Wallace’s ideas not necessarily my own. In any case, I suppose Mivart’s intended point is that greyhounds are an example of a domesticated animal that actually could survive in the wild. But the greyhound is a poor example of true domestication. Cynthia Branigan’s book, The Reign of the Greyhound, points out that the greyhound probably dates to ancient times when early humans and dogs living on the African plains began living together symbiotically. Stone Age peoples, according to Branigan, probably didn’t conscously breed dogs to create greyhounds, but rather recognized that dogs with longer legs were faster and these faster dogs could be of real value. Long-legged dogs who were faster were likely kept together were they would naturally breed together. So really the greyhound’s existence is more akin to true natural selection than it is conscious domestication and hybridization through breeding. I think Wallace’s comments are not in the least compromised by the example of the greyhound since the very trait (i.e., speed) occured naturally in the original breeding pairs.

  44. 44
    Flannery says:

    PS-It would appear the original greyhound comment was from O’Leary (the string gets a little confusing, but the statements above “Anyway, Flannery comments” are O’Leary’s and not mine). At any rate, my comments immediately above still stand.

  45. 45
    Mark Frank says:

    #43 (and others)

    None of these reflections on greyhounds throw any light on what Denyse is saying. There is a mysterious bit of logic that appears to go:

    Domestic animals are selected to prosper in man-made environments

    Domestic animals cannot survive in the wild

    Therefore selection of domestic animals is not really like natural selection

    It is an obviously fallacious argument. Few species are good at surviving in an environment in which they were not selected. Wolves and many, many wild animals fail to survive in a man-made environment.

  46. 46
    Nakashima says:

    in the domesticated animal all variations have an equal chance of continuance;

    I’m sure these really are Wallace’s words, after he is using a semi-colon correctly. However, he is quite wrong, since the whole point of artificial selection as an example for Darwin was that the breeder will only allow certain animals to breed, even if all those born are allowed to live (and no guarantees there).

  47. 47
    Flannery says:

    To #45: Your conclusion that “many, many wild animals fail to survive in a man-made environment” is actually not true. Your having the same difficulty Darwin did. Darwin
    saw competition as taking place between individuals while Wallace saw competition as taking place between populations. Darwin focused on individual struggles for existence while Wallace concentrated on population growth as the powerful modifying force in nature. Wallace saw evolution taking place not in an individual but in a demographic context. So to your point: Yes, wolf A or wolf B may fail to survive in a man-made environment, but it is simply wrong to say that as a group wolves cannot survive-or many other wild animals for that matter-cannot as a group survive in such environments. In fact, the artificial protective factor actually enhances their longevity with fewer exposures to parasites, bacteria, etc.

    As to #46, Wallace writes “an equal chance of continuance” not survival. He’s speaking of breeds once domesticated not “an eqaul chance” amongst a set of unbred or potentially bred animals. The chances of continuance are largely equaled out by the protection accorded by the breeder. This doesn’t happen in the wild.

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