The goal or good of evolution

I dug up an old article from The New Scholastic which argued for the goal or telos of evolution. Simplified, with a link to the major premise, the argument is lovely:

The diversity and distinction of things is a good

But evolution as such generates a diversity and distinction in species

Therefore, evolution as such produces a good.

 St. Thomas recognizes how easy it is to be wrong about the major premise (either by thinking multiplicity is accidental, or evil, which is very difficult not to do.) The minor premise is given from the terms: there is no evolution without some sort of diversity in species, and diversity in species is explained by evolution. So for Thomists at least, evolution- even in Dawkins’ terms- is teleological. Oddly enough, in an evolutionary world, natural species are more able to contribute to a primary good of the universe than a stable species would be. The goal is not flux, which is simply an instrument, it’s diversity and distinction, which is the goal.

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6 Comments

  1. William H. Stoddard said,

    May 26, 2009 at 10:58 am

    I’m not sure about that formulation. Your statement that “there is no evolution without some sort of diversity in species” is not an argument that evolution produced diversity; it is an argument that diversity produces evolution. Therefore, if you consider diversity to be a telos, this particular premise does not assert that evolution is a process that tends to accomplish the telos. Rather, it asserts that the attainment of the telos, by whatever means, is a condition that makes the occurrence of evolution possible. The evolution that results could be a byproduct of the diversity, rather than a goal.

    But I’d also note that in strict Darwinian terms, it is not diversity OF species that enables evolution to occur. Rather, it is diversity WITHIN a species. If a given species had no genetic variation at all, then there would be no traits to be selected over other traits, and the species could not evolve. And if there were a billion species each with that uniformity, then none of them could evolve. The only change that could take place would be the elimination of some species by successful competition from other species; and that would represent, not increasing, but decreasing diversity. Diversity of individuals is what enables evolution.

  2. May 26, 2009 at 12:45 pm

    “Evolution” in concrete terms is whatever constellation of natural causes that gives rise to a diversity of species. It either explains diversity in species or it explains nothing. A world with one species, now and forever, has no need of evolution.

    Notice I used slippery terms thoughout the post to ensure that I could include both inner and inter species diversity and difference. That wasn’t an accident. Both can be contained under the good that St. Thomas finds in multiplicity and distinction. All that is irrelevant is sheer numerical repitition of the same thing: ten wolves as opposed to nine, say.

    Your last paragraph is interesting, but off the point. There is more than one meaning to diversity. I’ll concede that any day.

  3. bob koepp said,

    May 27, 2009 at 7:04 pm

    James – I’m picking up our conversation from Bill Vallicella’s site to, I hope, clarify my views. To that end, I want to draw your attention to a distinction that I take for granted between evolution and natural selection. I haven’t claimed that evolution is non-teleological, — only that a process of natural selection is not itself teleological. That ‘s an important difference. And my comments should have made clear that I don’t view natural selection as the only, or even the most important factor influencing the course of evolution.

    But still, I do think that natural selection is important since it’s the only natural process we’ve identified that could drive _adaptive_ evolutionary change. The range of adaptations that could develop solely under the influence of natural selection, however, is very much an open question.

    And this brings me to question your claim that diversity is the telos of evolution. I happily grant that this might be so. But if we conflate evolution and the process of natural selection, there’s trouble.

    Since the process of natural selection is defined wholly in terms of efficient causes, qua natural selection it is not directed toward a telos. This is perfectly compatible with its being part of a larger process which, for all I know, might well be teleological.

    Regarding diversity, even though variation is a necessary precondition for the operation of natural selection (as noted above by William), there are conditions in which natural selection does not lead to increased diversity. In some circumstances it actually leads to a reduction in diversity. And in yet other circumstances it is a strong stabilizing factor. In other words, whether or not natural selection promotes diversity is a contingent matter. If you want to maintain your view that evolution has diversity as a telos, this is yet another reason to distinguish clearly between evolution and natural selection, since a contingent relation won’t support a robust telos.

  4. May 27, 2009 at 8:37 pm

    Bob,

    I think both you and William are making this harder than it is. Why do new species arise? The mechanism that does this is a cause of diversity throughout history.

    You say it need not happen in every instance. This is fine. Natural ends are not such that they need to be realized in every instance. Trees drop acorns to reproduce even though few succeed. It suffices to see diversity of species as reducing to evolution as to its per se cause.

    I deny the premise of your fourth paragraph. Agents cannot exist without some determination to an end, but that’s another topic.

  5. bob koepp said,

    May 28, 2009 at 3:26 am

    James – So, are you rejecting the distinction between evolution and natural selection? I didn’t just say that “it” doesn’t happen in every instance. I poionted out that “it” is contingently related to the process of natural selection. And, who said the process of natural selection is an agent? It seems pretty clear to me that it isn’t.

  6. May 28, 2009 at 4:36 am

    “The process of natural selection is defined wholly in terms of efficient causes” Efficient causes are agent causes. That’s just the lingo.

    I’m not rejecting a distinction between selection and evolution absolutely, but I am rejecting one so far as if one wants to point to positive causes of diversity, evolution and natural selection both are acceptable answers. Both can be cited as per se causes of diversity throughout time, which is precisely what both I and St. Thomas see as one of the chief goods of the universe.

    As a clarification: when I speak of variation of species I include species throughout time. If four species give rise to one and then the original four go extinct, this is a net gain for diversity in the universe. It counts as five species. The very flux character of the universe implied by evolution is what I’m referring to when I speak of the diversity of species.


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