Posted by Walker on May 11, 1998 at 19:22:45:
In Reply to: On speciation posted by rpcman on May 08, 1998 at 11:18:30:
I read "Observed Instances of Speciation" by Joseph Boxhorn.
Very interesting. In order to really understand what is being said, I would have to
take the time to research all the terms and concepts; but I will make a few comments
anyway, with my unlearned mind:
First of all, the definition of speciation seemed rather fuzzy; at the very least, it
depends on what organism(s) are being observed.
In Boxhorn's introduction he says, "Part 5 describes a number
of observed speciation events and several experiments which (IMO)
failed to produce speciation."
An example follows:
5.3.2 ... They found that they had produced a high degree of
positive assortative mating between the two groups. In the decade or so following this,
eighteen labs attempted unsuccessfully to reproduce these results. References are given in
Thoday and Gibson 1970.
I guess "positive assortative mating" means a premating, isolating mechanism which would
indicate speciation. Does this mean if two groups of humans are unattracted to each other
that they are different species?
You would think after 10 or so unsuccessful attempts to reproduce an experiment, they would give
up. But I find it heartening that biologists are trying hard to apply scientific principle to their
experiments and conclusions.
In many of the observed speciation experiments, there was no claim that an attempt was made
to reproduce the results.
Many of the experiments used hybridization to generate new species. I don't think the theory
of evolution relies on (or could be supported by) this type of speciation.
Baxhorn asks the following question, then answers it:
Why is there such a seeming lack of interest in reporting
observations of speciation events?
IMHO, four things account for this lack of interest. First, it appears that the biological
community considers this a settled question. Many researchers feel that there are already
ample reports in the literature. Few of these folks have actually looked closely.
Perhaps we could say these folks have faith in speciation and evolution. It's kind of like
in testimony meeting where you hear, "I received a blessing and I was healed". But you never
hear a story like, "I received a blessing that I would be healed but I wasn't." (And we all know
such failed blessings happen) You rarely hear
about the non-faith promoting stories just like you rarely hear about the experiments in evolution
which don't really support the theory. I'm gratified that Baxhorn points the failures out so
readers don't have to be the victims of selective evidence.
I hope I'm not misunderstood; I'm not trying to prove evolution false, I'm just trying to say
that it appears that the experimental evidence to support it is not as strong as other branches
of science.
Einstein boldly predicted that the sun would bend sunlight. I believe he made this prediction
before any such measurement was ever made (An eclipse of the sun was required) On the first try,
the predicted "light bending" was observed. (Okay, it wasn't exactly right because Einstein hadn't
yet come up with general relativity) But after the adjustment was made for the general case,
his prediction has been borne out in experiment after experiment.
Didn't some physicist predict the existence of the positron? Didn't someone predict black holes
and neutron stars long before they were observed?
I can buy the argument that evolutionary forces are more complex and hence evolution is
more difficult to observe but at some point, at some level, someone must come up with a simple, repeatable, experiment
that irrefutably demonstrates evolution at work. (I haven't yet looked at the examples Chris suggested)
I bare witness that I know Newton's laws are as true as I know the sun will rise in the morning. I confess that my
testimony of evolution is not so strong.
Again, I'm not trying to say anyone is right or wrong. I'm just trying to make an honest
inquiry. Thanks for the info, rpcman.