Re: Dawkins

Gordon Simons (simons@stat.unc.edu)
Fri, 8 Sep 1995 20:24:11 -0400 (EDT)

Concerning a comment by Dawkins, Bill writes:

"Saying that evolution cannot predict what man will be like in a million
years is quite reasonable. That's not the sort of prediction we are
talking about when we talk about the predictive power of theories.
(Besides, I really doubt the Lord will tarry another million years, so why
bother? :-))"

Of course, this is a valid point: One simply needs to replace "what man
will be like" by "what the solar system will be like" to see the
reasonableness of Bill's point. Chaos is a fact of life.

Then Bill adds:

"But if he said evolution has no predictive power at all -- meaning that
it cannot suggest further investigations and experiments, then I'd say
that was news."

I do wonder. What is the predictive content of evolution beyond broad
generalities? Perhaps it does "suggest further investigations and
experiments". But, as Niels Bohr once observed, prediction is hard
because it describes the future. (The precise quote is better than this,
but I could not find it on short notice. Does anyone remember it?)

As I complete this, I observe that John Burgeson has just made a similar
point.

Of course, one of the problems is time scale. Neither evolution nor
geology describe processes that move fast enough for predictions of the
future to be of much value for human observers. In contrast, the laws of
physics behave much more quickly - fast enough for us to see clearly.

Gordie