Re: transitional fossils

Cornelius wrote:

> Prediction: The fossil species should form an evolutionary tree.
>  
> Falsification: The fossil record reveals a series of "big bangs"
> followed by a thinning of the ranks by extinctions. In each "big bang"
> new species appear, and then they remain unchanged until they reach
> extinction. If anything, it appears more like an inverted evolutionary
> tree. Rather than the prediction of a single trunk leading to many
> branches and twigs of diversity, what we actually find is the
> opposite: the rapid appearance of species followed by a narrowing as
> species reach extinction.

This in no way falsifies common descent. These are issues with regard
to the tempo of evolution. The rapid radiation events, which often
follow mass extinction events, are resolvable into a rapidly branching
tree or bush. It is in fact during just such radiations that we would
expect to find, and indeed do find, the transitional forms between the
higher taxonomic groups. The examples that I referenced in an earlier
post are found during the time intervals of just such rapid radiations
(which occur over tens of millions of years). It is the prediction of
the tree of life that the criteria used to distinguish higher taxonomic
groups should break down as we approach the common ancestors of
lineages. That is what we find in the fossil record. It is during
times of rapid radiation that fossil specimens often defy
classification.

Also, new species continue to evolve after major radiations. You seem
to be using the term "species" in a colloquial rather than a
biological/paleontological sense. It is simple false to state, or
imply, that species all appear during some instantaneous episode
without intermediates, and then remain unchanged until their extinction.

Evolution of new significant characters does not occur at a uniform
rate -- in large part because the natural environment constantly
changes and at highly irregular rates. No one has suggested anything
different. Even Darwin, who is seen as an advocate of gradualistic
evolutionary change, explicitly stated that evolutionary rates are not
uniform.

>
> "Also please provide any non-evolutionary theory
> that explains the fossil evidence that common descent effectively
> predicted."
>  
> This is ambiguous. For instance, what does "non-evolutionary" mean?
> Darwin made it clear that the main purpose of his theory was to
> overthrow special creation, and that NS was merely a subhypothesis
> that could be traded for Lamarckism, etc, if need be. Likewise, later
> evolutionists have been quite flexible in considering a wide variety
> of mechanisms outside of the traditional RV/NS (saltations, etc). The
> only hypotheses that are clearly outside of evolution are supernatural
> ones.

I have been arguing about common descent and the overwhelming support
of the fossil record for that model (which you have challenged).
Common descent is the core of the general theory of evolution.
Non-evolutionary means a model that does not accept common descent.

Keith

Keith B. Miller
Research Assistant Professor
Dept of Geology, Kansas State University
Manhattan, KS 66506-3201
785-532-2250
http://www-personal.ksu.edu/~kbmill/
  
Received on Sun Dec 4 17:36:21 2005