GrumpyMrGruff wrote:Sorry about the delay. The real world intruded for a bit.

No problem. It intrudes quite often on me too.

We cannot observe accumulations of genotypic/phenotypic variation which occur on super-human timescales. We can observe organisms with different morphologies over time (fossils) and a hierarchical pattern of genotypic similarity in living organisms. We can apply observable mechanisms – drift, mutation, and natural selection – to parsimoniously connect the dots between observations.

Most of the dots that needs to be connected are from fossils. Yet, there is a severe lack of genetic information from fossils to be able to connect the dots genetically. So, the processes that you mention (drift, mutation, natural selection) would not be applicable to the fossil record.

Note that I am proceeding under the assumption (which I haven’t seen you dispute) that the most parsimonious (and therefore the best) method available for making inferences about the past (especially the prehistoric past) is to extrapolate backward from known, observed mechanisms.

I would say that parsimony would be one element in determining the best explanation, but not the only factor.

Further, I am not suggesting that a designer be dismissed because it cannot be observed. I am suggesting that it is a less parsimonious explanation because such designers have not been observed. Invoking a designer requires more unconfirmed mechanisms than evolution and is less therefore parsimonious.

The evidence for a designer spans many other areas, other than just this topic we are considering. So, in terms of parsimony, there is one common explanation that addresses many issues (eg origin of universe, anthropic coincidences, fine-tuning). Not only is it a parsimonious explanation when viewed across multiple disciplines, it has the most explanatory power.

I agree that a supernatural designer cannot and have not been observed. But, in neither case would it mean that it should be dismissed. As you’ve stated “we cannot observe accumulations of genotypic/phenotypic variation which occur on super-human timescales”. And this conclusion is not automatically dismissed by you since it is unobservable. So, observability should not really come into play in determining the validity of an explanation.

You have brought up this macro/micro distinction without illustrating any mechanistic difference between the two.

I do not claim that there exists any natural mechanism to account for macroevolution. The distinction is that genetic changes/natural selection can only account for microevolutionary changes. It cannot account for macroevolutionary changes.

And if you do claim that it can account for it, then the burden is for you to show that it can produce such changes.

This seems like a category error, because the parsimony of an explanation does not require that anyone observe an unobservable (by definition) process. Rather, the parsimony of an explanation requires that the underlying mechanisms be observable.

I do not believe that I’ve stated anywhere that it is a requirement to be able to observe an unobservable process.

You seem to be saying that I am employing a double standard invoking an unobservable mechanism

That would be true.

Conversely, you haven’t described any mechanisms of the proposed designer (and to my knowledge we haven’t observed the designer in action).

I think we covered this before. It is not necessary to know how something was created to infer that it was created.

How does the designer provide a more parsimonious explanation with fewer unknowns? (What known mechanisms are you extrapolating from?)

If one looks across multiple disciplines, there are certainly fewer unknowns with a supernatural designer than natural processes.

What I have shown is that from human experience in the domestication of animals, there is not much significant change in morphological features in animals to account for common descent.

You’ve provided an example spanning a few millennia. The timespan in question is millions of years. Why should we expect to see the same degree (quantitative) of genotypic change (and corresponding phenotypic change) on human timescales? Again, unless you will describe a difference of mechanism for macroevolution (i.e., why you have reason to suspect observed mechanisms are incapable of accounting for the diversity among species), you aren’t making much of a case against the validity of the evolutionary extrapolation. The whole purpose of this exercise is to extrapolate beyond historic timescales (many times the scope of all recorded human experience, which goes back only some thousands of years).

Here we can apply your principle of observable processes and extrapolation. If we apply what we observe to millions of years, the consistent position would be that the same result would occur – there would not be much significant change in morphological features. If you state that there would be significant morphological change, then it would be in conflict of what we observe.

I think that macro/micro is as arbitrary a categorical distinction as species.

On this, I would agree with you.

How does your micro/macro distinction help us understand anything?

Because if all life arose from a single cell, then it would somehow have to account for major novel morphological features found in all organisms since the first cell.