Re: Bipedalism and theorizing... (Wegener, Copernicus and others)

Maia (dalmiro@mesopy.obspm.fr)
Sun, 14 Jul 1996 18:52:20 +0200

Thomas Clarke wrote:
[snip]
> There is a good parallel here with the Wegener debate.
> David Burkhead seems to consider mechanism essential to science.
> Without a good mechanism - like Wegener, like Copernicus -
> you are not doing science.
>
> I guess that this is a valid position, but then I think
> Mr. Burkhead for consistency would have to say that
> Darwin was not doing science. After all Darwin did not
> have a mechanism for how variation and selection operated.
> He could only point to animal breeding as a kind of analogy, but
> no one even understood how animal breeding worked in Darwin's day.
> It wasn't until decades later that he work of Mendel began to
> elucidate the mechnisms of heredity.
>

You are confusing things, situations are a bit different.
Wegener had data that suggested that continents were once together.
He then makes the hypothesis that continents move by some sort
of mechanism, i.e. continents moving makes part of the hypothesis.
Wegener mechanism was wrong therefore all of his hypothesis
is refused.

Variation within populations is a fact not a hypothesis.
Evolution is also a fact: new forms replace old ones.
Darwin hypothesis was that natural selection was the driving
force behind evolution and that the new forms descended with
modification from the old ones, he didn't give a mechanism
to provide variation but a mechanism to explain evolution.

There are two different things here: Darwin finding a mechanism
to explain a fact, Wegener finding a mechanism to predict something
that later was established as a fact (but not at that time).
You can use variation (a fact) without providing a mechanism, but
you can't expect people to accept movement (not a fact then)
without giving them reasons to do so.

> Returning to Copernicus, he said the earth moved, just as Wegener
> said the continents moved, and ust as Darwin said that species were
> not constant - they moved.

As stated before, darwin did give a mechanism to explain evolution (a fact).

> Once the possiblity, the probability
> of the earth's motion was admitted then others - Galileo, Kepler etc
> were freed to find mechanisms for the motion.
>
> Tom Clarke

The problem with Copernicus is that he was not interested in finding a
better model to explain data, his position was of extreme prejudice:
finding a model consisting only of circular motions. Kepler didn't really
provide a mechanism, but he had the right scientific posture, without
prejudice: the simpler explanation is to assume that planets don't follow
circular orbits but elliptical ones. It was Newton that later provided a
good theoretical framework.

Finally just a comment: this is a very interesting subject but off-topic.
I suggest people let it die or change the discussion to another group

D. Maia