Well, now that we've apparently argued to a standstill, I'll like to repost an earlier post of mine that got lost in the shuffle, which dovetails with Autodidact's discussion of the DNA evidence for evolutionary theory:
The principal assertion evolutionary theory makes is that all life on earth is descended from one or a small number of universal common ancestors. The best summary I've ever read of the evidence supporting this assertion is contained in Douglas Theobald's "
29+ Evidences for Macroevolution." While the Theobald article is a literature review and as such contains no original research, and has not undergone formal peer review, Theobald informed me in an e-mail dated Oct. 18, 2005:
I'm going to try to keep quoting from the article to a minimum, but I strongly suggest that anyone who is truly interested in the strength of the evidence supporting macroevolutionary theory read the article in its entirety. It's easily the project for a long weekend, if you read it thoroughly and carefully. If you want to follow up on the extensive references, you're probably look at more like a month's worth of reading.
Also,
please do not point out that none of these lines of evidence are "proof" of evolutionary theory. There is no such
thing as "proof" of evolutionary theory. Theories are not capable of being proven. Predictions a theory makes can be confirmed, or falsified. A successful prediction only means that the theory is correct
so far. A falsified prediction means that the theory needs some working on, or if it is a significant failure, it may mean the theory needs to be abandoned.
But I will not respond to requests that evolutionary theory be proven. It cannot be proven, any more than any scientific theory can be proven.
So let's take a look at the first piece of evidence Theobald cites as evidence for macroevolution:
The Fundamental Unity of All Life
All living organisms essentially do the same things. They take reproduce themselves, either sexually or asexually, they impart inheritable information to their descendants, they catalyze chemical reactions, and they use energy to accomplish these tasks.
All living organisms use essentially the same biochemistry to perform these tasks. All living organisms use the same (or closely related) genetic code, the same (or closely related) amino acids, and the same (or closely related) metabolic pathways.
Since evolutionary theory proposes that all organisms are related by common descent from a universal ancestor, it predicts that all the biochemical means by which organisms perform these processes should be similar, and slight differences should be modifications of some ancestral form. Such a prediction is trivially falsifiable by a finding that various organisms use completely unrelated genetic codes, unrelated chemical catalysts, unrelated metabolic pathways, etc. That we do not find such unrelated biochemical systems is a confirmation of this prediction.
As an example, all living organisms that have ever been studied have been found to use adenosine triphosphate as a basic unit of energy storage. There are hundreds of different molecules that would serve equally well, yet all living organisms use this same molecule.
It can, of course, be argued that a creator being could use the same basic building blocks over and over: the concept of common design. This is of course, true, but it is also an unfalsifiable assertion. There is no necessity that a creator use the same basic biochemistry in all living organisms.
Logically, if hypothesis X predicts observation A, but would be falsified by observation !A, then observation A is evidence for hypothesis X, while observation !A is a falsification of X. Contrarily, if hypothesis Y predicts A, but would not be falsified by !A, then neither A nor !A is evidence for Y. Since special creation may predict a common biochemistry among all living organisms (common design) but could still accommodate widely varying biochemistries (because a sufficiently advanced creator could do so), neither observation is evidence for a special creation. On this particular matter, therefore, special creation makes no falsifiable prediction. An observation of a universal biochemistry cannot tell us whether or not life was specially created by an intelligent designer.
