I started this as a new thread because the orignal was getting rather long and distant from the OP. Mad Dog and I were circulating what, I maintain (or admit) are some fairly specific grounds for starting the discussion.
He was defending a version of (as I understand it): It is unfounded or irrational to accept the theory of evolution as probably true because either the evidence is insufficient compared to what should be observed according to the theory OR the evidence observed, while corresponding to the theory, nevertheless is based on unfounded or irrational assumptions.
He is not saying, as I understand it, the following: There exists some evidence which either falsifies the necessary conditions OR some other theory which better fits the data.
I was defending and will defend: It is rational to accept the theory of evolution as probably true because the evidence closely corresponds to and is sufficient compared to what should be observed according to the theory and (if we ever get there) it is irrational to reject or postpone judgement of the theory on these grounds.
I'll certainly leave the last half for now, and cut right to the chase in as terse a way possible to allow a likewise pointed rebuttal.
If the theory of evolution were true...
1. The necessary condition of variation within a population of organisms should be observed.
2. The necessary condition of a means of heredity should be observed.
3. The necessary condition of mechanisms os selection should be observed to act on, within and between populations of organisms.
(These conditions, if proven, satisfy that the theory is at least possibly true, but does not constitute grounds to determine rational belief or disbelief in common descent.)
4. There should be evidence observable in the present and derivable through repeatable analytic means therefrom that life has existed on earth for a long time with respect to the life span of any known organism.
5. Any evidence for the existance of past life forms which is observable in the present should by comparative anatomy, geographical location, computational dating and other methods correspond to the prediction of the descent of species from common ancestors.
6. The current biogeographical distribution of species alive today should be observed to correspond to the theory of common descent and also fit the evidence in (5).
7. Given genetics, the observable evidence in (6, some of 5, some of 1-3) should be verified to match any corresponding prediction derived from the theory.
(These observations, a posteriori, would constitute strong evidence for the conclusion that probably, evolution is true and may or may not constitute logical grounds for rational belief depending on exactly how an opposing position is developed. Given no opposing position, my conclusion would hold unless it can be established that either the necessary conditions are not met or that of necessity more evidence is predicted by the theory than is shown in 4-7. Mad Dog has not claimed, for instance, that something exists for which it is impossible for evolution to account. Some may claim consciousness, love, music, irreducible complexity, human language, etc. There are additional arguments which can be made against specific opposing theories - but as a null situatin of reserving judgement has been taken I'll leave it at these.)
Yes, of course all of these require extensive elaboration, have many corollary modifications and additions, etc. It might be worthwhile before proceeding to at least deal with the premises. Here is the opportunity to substantiate the claim that No, even if all these were satisfied, it would still be irrational to believe that evolution probably occured for some other reason.