>Glenn, you have drawn an analogy between 'unobservables' in particle physics
and hypothetical transitional forms in evolutionary biology. I think to be
fair it must be pointed out (as you did earlier in your post) that there are
good reasons to expect that we will NEVER be able to observe an isolated
quark, and that observational confirmation of the existence of gravitons will
be VERY DIFFICULT. These expectations arise from theory itself, having to do
with the increedible strength of the nuclear force and the relatvie weakness
of the gravitational force, respectively. Is there a similar expectation
withing evolutionary theory (or paleontology) that transitional forms should
be impossible (or very difficult) to observe in the fossil record?"<
Ah, my mouth gets me in so much trouble. But I was ready for you this time,
Stan. Not enjoying having to admit that I was wrong as I did last time you
challenged me, I looked everything up before I posted. :-)
The short answer to your question is that yes there are excellent theoretical
reasons for not expecting to always find transitional forms. In the Williston
Basin, there are about 15,000 feet of sediment representing the rocks of all
geologic ages. Thus from the Cambrian to the present is 580,000,000 years.
That represents an average rate of deposition of .0003 inches per year. Under
these types of rates, not many of the organic remains are going to be
preserved. What ends up being preserved are the surficial sediments which are
lucky enough to be laid down, when the basin makes one of its episodic
lowerings which take the surface significantly below the average rate of
deposition. The basin does not fill by absolutely .0003 inches per year but
fills bysudden floods which do hundreds of thousands of years of deposition in
a month or less.
Take the 1993 Mississippi floods. They deposited 6 feet of sediment. The
likelihood is that that sediment will slowly erode over the next several
centuries until there is only a small part of it left. The next flood may add
or subtract to that 1993 deposit. With this as a background, perform a
volumetrically based probability that any given fossil will be preserved.
Remember, on average when 6 feet is added in a year, an average of 6-.0003*Y
will be eroded away before the next flood. Y is the number of years the
erosion occurs in. The rate of subsidence of the basin also plays a role in
how much on average is saved. These numbers do not give a large probability
that a given bone will be preserved. Only the events which greatly exceed the
average deposition rate will be preserved. This means large scale floods and
landslides will be preferentially preserved in the fossil record.
The reason my analogy between the unobservables and some species works is that
both sciences are believing that something exists which has not been directly
observed. I see no difference if this is species or if it is quarks. If I
replaced quarks with pixies I could say that what physics should examine is
the pixie theory of nature. (I do not know how to calculate particle
cross-sections from pixies but give me a while and I will figure it out. :-)
) What the quarks are are mathematical constructs whose existence unites a
whole lot of otherwise disparate observations. The same thing with the
connecting species.
In the case of the connecting species, I would dare say that until we have a
complete father-son genealogy from man to great-grandfish, some will never
think it is possible.
glenn