Music

Steve Bougerolle steveb at creek-and-cowley.com
Sun Jun 16 15:38:03 PDT 2002


On Mon, 2002-06-17 at 00:24, Don Smith wrote:

> > The absence of
> > intermediate forms can be explained partly by the difficulty of finding
> > fossils, but that isn't really convincing
> 
> Well then we just disagree because it is convincing enough for me.

Maybe I overestimate the number of fossils because I come from an area
where they're as common as dirt :-) (that being southern Alberta).

Ok, seriously, let me be more specific about where I disagree. I am
aware that speciation has been observed, and I don't find it at all hard
to accept that accumulated random mutations can create new species in
general.  However, I do find it an unsatisfying explanation of a few
particular steps. In particular, it doesn't seem to me at all a
satisfactory explanation of how multi-celled life can evolve from
single-celled life.

> > and it does nothing to address
> > even bigger problems like the beginnings of single-celled life.
> 
> Now, here I agree there is a problem. But then it is not really with
> evolution because evolution theory presupposes ancestors. 

Well, if your point is simply that macroevolution occurs, then we can
stop arguing because I agree with that as far as it goes.  My dispute,
ultimately, is with too many people who leap from there to saying that
it is a complete explanation for the shape of life as we see it, and
then go on to (generalizing) make pronouncements that there is no
planning or direction to the universe.  My religious interest only kicks
in at this point, and as I said I am concerned with ethics, not
interested in any sort of creationist debate; I don't like this view
because I see it leading to a gross lack of respect for life and a
dangerous overconfidence in how much we know.  In my first post way back
when I commented on a couple signs of this; people trying to patent
genes and blithely indulging in genetic modification for short-term
commercial advantage.

> Hmm. Natural selection is a term used to differential naturally occuring
> selection pressures from human selection of the most desirable traits in
> domesticated species. Predation, sexual preference, enviromental
> changes, etc. all are natural forms of selecting for the most fit
> individuals. Darwin did not prefer sexual selection over natural
> selection, he came to see it as a very important selection mechanism
> under natural selection.
> 
> There is a better explantion here:
> 
> http://www.sprl.umich.edu/GCL/paper_to_html/selection.html

Thanks for the reference.  I brushed up on the latest from talk.origins
last night, reviewing punctuated equilibrium and genetic drift and so
on.  All nice to read, but all just word games.

> > It might be that someone can show a satisfactory selection mechanism.
> > However, I'm not going to be impressed by simple word arguments.  Darwin
> > could get away with that but in this computing age I expect to see some
> > probabilistic analysis.
> 
> They've been done. Another argument creationists use to attack evolution
> theory. They keep ignoring the immense amount of time and large
> populations involved in evolution theory.

You say they've been done, but I haven't seen a nice comprehensible
summary of the results anywhere and I just went looking for one
yesterday.  This is another way in which evolutionary theorists make
trouble for themselves and reinforce my impression of their bad
attitude; when people ask simple critical questions they are too often
dismissed as nutty creationists instead of being given simple direct
answers. I am not a creationist, except perhaps in the broadest sense of
thinking of the entire universe as a creation; I accept large areas of
evolutionary theory, but I am not blind to its weak spots and being
extremely far from being a layman, I am not about to roll over and
accept rubbish when people toss it to me as an explanation. 

Here's what would make me happy.  I did find one brief cited reference
to a paper where somebody came up (by some means) with a figure of one
instance of speciation per 3 million years per species.  If somebody sat
down with all the best guesses they could come up with here, and applied
a bit of probability to them with varied parameters, to come up with an
overall range of probabilities for, say, a badger evolving from nothing,
that would make me happy.

Of course, there is the question of whether it would mean anything.  On
the one hand there's thermodynamic-style reasoning; if the probability
is so low that it would never happen in a billion times the most
generous age estimate of the universe, that would tell me conclusively
that biologists are missing something.  If the figure is significantly
lower, then we have to consider the anthropomorphic principle and the
result is unclear, but it would still be interesting just as a measure
of how much we don't know.  

In any case, it would be a lot more satisfying than word answers to a
mathematical problem.

> Okay, I accept the 65 million year time because I understand how they
> arrived at that figure. But I'm willing to say it can be any number you
> like because it is not a fact. However, finding only a few species of
> rodent-like mammals in the lowest strata, is a fact. Increasingly higher
> strata contain increasingly more diverse species of mammals, is a fact.
> Higher strata must have been laid down after the lower strata, hmm, not
> a fact but an inference. Can you reasonably explain the lower strata
> being newer? And mammals are just one example out of hundreds of
> classifications.

The straightforward answer to this is that as you go farther back in
time you would expect the record to be more skimpy because more would
have been destroyed in the longer period since being laid down.  In
itself it says little about how common life forms were then.  We need
some sort of model to fit these things into; it is a mathematical
question again.

-- 
Steve Bougerolle
Creek & Cowley Consulting

http://www.creek-and-cowley.com

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