Natural vs. unnatural selection: Consider the ceaseless yap of the lap dog and be warned
| June 21, 2009 | Posted by O'Leary under Intelligent Design |
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 Responses to Natural vs. unnatural selection: Consider the ceaseless yap of the lap dog and be warned
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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.
@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?
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
#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?
#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.
Mark Frank:
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.
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.
#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.
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.
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.
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,”
#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.
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.
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.
#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.
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).
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.