Richard Wein wrote:
>I said quite clearly that I was *not* using Darwinism to mean Darwin's
>understanding of the process of evolution. Since no-one (if they know what
>they're talking about) understands evolution in that way any more, it would
>be pointless to use Darwinism in that sense except for historical accounts.
>But the term Darwinism is still used widely in contemporary references, so,
>to be meaningful, it must mean something else. I have suggested a reasonable
>meaning for it, and it's the one that I intend to use. At least I've defined
>what I mean by it, which is more than can be said of most people who use the
>term.
For me, Darwinism means two things:
1. Evolution in general.
2. Pure gradualism; no leaps in phenotypic evolution.
#1 Everybody is happy with #1, but #2 is dubious. ID people are eager to
lump the two together, so that #1 suffers from association with #2. When the
term 'Darwinism' is thrown around, this confounding of meanings is bound
to occur. That's why scientists don't use the term; it's mainly used by ID
advocates and those who get sucked into arguing with them.
>Perhaps it would be better to avoid the term altogether. But none of the
>alternatives seem to be any clearer.
If alternative terminology distinguishes evolution-in-general from
obligatory phenotypic gradualism, that would seem clearer than a
term which does not make such a distinction.
>>Is the point that gradualism is saved if only we focus on the 'real core' of
>>things, the genetic level? How do you quantify and compare genotypic
>>complexity? You don't seem to want to judge by the morphological effects,
>>you seem to want to come full circle and judge genetic mutations by their
>>base-pair morphology, their most meaningless aspect. It's like talking
>>about ink and fonts when the topic is literature.
>
>If you don't like my definition of gradualism, that's OK--don't use it.
I am an advocate of macroevolution, I think it has been a significant
mechanism in evolutionary history. I have to wonder what is going on
when people suggest that large sudden phenotypic changes--such as
Siamese-twinning or drastic loss of anatomy--are 'really' just small
changes, because they flow from genotypic changes, and genes are
just little bitty things. What exactly are they trying to defend?
>But the version of gradualism that you like to argue against is not one that
>anyone wants to "save". It's a straw man.
OK, what is the proper version of gradualism?
>If that variation is random (as you define it below), then gradualism (in
>the sense that I define it) *is* essential, because substantial increases in
>functional complexity within a single generation are too improbable. (I
>should have written "functional complexity", instead of just "complexity",
>since any old random collection of parts can be complex.)
A change from a single cell into a chain of such cells is a big change
in functional complexity in the real world. Likewise with higher organisms
suddenly giving rise to chains of identical organisms. If you just want
to keep focusing on that one segment that is unchanged in itself (for the
moment) then you are missing something major. If you don't think
macroevolution has occurred in evolutionary history, you can argue
against anybody's specific macroevolutionary claim, but you can't
just define macroevolution away.
>Maybe my use of the word gradualism is only confusing the issue. I thought
>it was useful to have a word to sum up the limitation on the kind of changes
>that can be made by natural evolution in a single step, and there doesn't
>seem to be any other word available.
There is absolutely no logical limitation on what can be achieved in
one step. This is about what probably has happened in a complex
evolutionary history, not about natural laws. There's no point in
talking about limitation in a general sense, because there is no
general limitation.
--Cliff Lundberg ~ San Francisco ~ 415-648-0208 ~ cliff@cab.com
This archive was generated by hypermail 2b29 : Sun Aug 27 2000 - 19:10:35 EDT