Comment on An apology to PUC by Sean Pitman.

@OTNT_Believer:

I think you missed my point! I agree with you, I just don’t agree with developing a totally new set of terms to describe what I believe is going on when the existing terms, with some degree of tweaking, will work just fine.

While we both agree that there are limitations to the evolutionary mechanism, we don’t seem to agree when it comes to the clarity of the “species” concept – and therefore of the “macroevolution” concept. This is why Brand says that he believes that “some forms” of “macroevolution” are possible. It is important that he use the qualifying phrase “some forms” when he talks about macroevolution because, without this qualifying phrase, the term “macroevolution” is too ill-defined to be very useful in a discussion of the potential and limits of the evolutionary mechanism.

Again, I never said that one shouldn’t use the terms “macroevolution” or “species” from the creationist perspective. What I said is that one should not use these terms without qualification. One must define the limits of “macroevolution” and upon what, exactly, these proposed limits are based in a discussion of the proposed potential and/or limits of evolutionary mechanisms.

Now, as a creationist, I believe that megaevolution is not possible. I believe macroevolution, as modified above, works fine.

It all depends upon what you mean by the term “megaevolution”. If you mean that it is impossible for RM/NS to generate novel systems of function regardless of the level of functional complexity under consideration, then you’d be wrong. The evolution of truly novel functional systems is not only possible, but is commonly demonstrated in real time. It is just that all of these examples are at a very low level of functional complexity…

So, again, one must be more precise in exactly where the line should be drawn between different biblical “kinds” of gene pools.

Your theoretical description in another message above is fine but like the biological species concept, which you want to replace, it is extremely difficult to see how it can be applied in practice, especially considering the fact that the proteome for even one eukaryote has yet to be fully determined.

I never said that it would always be easy to clearly determine a unique uncrossable barrier between gene pools of different “kinds” of living things. A great deal more information than we currently have available would be needed in many cases. However, it is important to have the basis for approaching such a determination in place. Otherwise, there really is no basis upon which to even look to make such a determination – even if it ever did become possible, much less practical, beyond a theoretical proposal.

And as for Darwin’s finches, your proposal to include them as conspecific with other domed-nesting birds would get you laughed out of any group of taxonomists. What good is a definition like yours if it has nothing to do with morphology, or even with the ability to interbreed? You can say you think they would easily interbreed, but on what basis? There are cryptic species of fruit flies that don’t interbreed, even though morphologically we can’t tell them apart.

The biological species concept is not based on similarity of appearance. Although appearance may be helpful in identifying species, it does not define a species – even according to mainstream taxonomists.

There is a difference between species that don’t interbreed vs. those that can’t interbreed to produce viable offspring. There are many reasons why certain groups of animals don’t interbreed in the wild that have nothing to do with their potential to interbreed to produce viable offspring.

This potential to interbreed is a very important clue in determining the possibility of being part of an original ancestral gene pool within recent history – especially given a lack of a complete protenome for a given type of organism (as you’ve already pointed out).

You won’t find an evolutionist or taxonomist alive that doesn’t recognize the deficientcies in the current concept. So what! Taxonomists still use it because it is the best we have, and yours, in practice is actually worse, because short of a thorough proteomic comparison among all the taxa of interest, how will you ever know where to draw the lines? And considering the argument you are making, it must be a proteomic comparison, as a genomic comparison only tells part of the story. Now that we have become more acquainted with the RNome we know that it exerts a vast amount of control over what types of polypeptides are produced.

This is absolutely true! I’m not suggesting that my system is easily applied. It isn’t. It is based on a sound theory that has excellent predictive value given a known set of data. However, obtaining the data itself will no doubt be quite challenging. At the current time, my system is much more easily applied to simpler systems for which much more detailed information regarding the gene pool/protein pool is actually known (like E. coli).

However, the lack of detailed information regarding the entire gene pool or protein pools for higher level organisms does not mean that the function-based concept is therefore useless. Whenever higher level functional differences between gene pools are discovered, the functional concept can be used to propose the inadequacy of the RM/NS mechanism to explain such differences.

Maybe when we get better at the types of molecular analyses necessary your concept would be ready to be used, but even then, I think it would be better used to separate macro from mega, rather than as a species concept.

Maybe current species concepts would still have some utility given such advanced knowledge, but probably not much. Certainly at the current time the species concept is generally useful, but it still needs to be qualified in discussions like this one concerning the potential and limits of evolutionary progress over a given span of time.

The only real disagreement I have with you (beyond your comments on the dating of Egyptian dynasties) is over your assertion that certain species, like Darwin’s Finches, are so clearly unique from all other species that they cannot be rationally explained as being reproductively isolated over a period of just a few thousand years. I think you’re overreaching in this particular assertion of yours. As far as I can tell, you haven’t demonstrated the need for significantly longer periods of time to explain the seemingly minor genetic differences (most of which seem to be non-functional) between different members of the “domed nest clade”.

Sean Pitman
www.DetectingDesign.com

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