hecd2:
Isn’t that the crux of the matter? If one makes the claim that a particular organism shows transitional features, doesn’t the question between what and what immediately arise?
No, I’m just as happy to discuss the situation as A → B → C.
How bizarre. Surely any discussion of a particular transition (in this case from free-living bacteria to organelles), even if intended to form the basis of an argument which leads from the particular to the general, turns on the special characteristics of the particular. Otherwise you might as well talk about slush as a transitional form between snow and water, or adolescence as a transitional form between childhood and adulthood (or fathers as a transition between grandfathers and grandchildren). These are clearly things that lie outside the biological definition of a transitional fossil, but by not grounding the discussion in the specific, you are creating confusion where none exists.
I was pointing out the imprecision of your definition - and this is one of the points I was making. The definition of the term intermediate doesn’t appear to have a precise meaning given that between you, Rossum, and Wikipedia there are four.
It was not my definition, but Darwin’s. Surely we can allow Darwin to be able define the thing that he is talking about. As far as I can see it is a precise definition provided that you take it, as it is meant, in the context of mutability of species. I notice that in the Wikipedia article on entropy in thermodynamics, there are five definitions of entropy (in classical thermodynamics, statistical mechanics, chemical thermodynamics, quantum mechanics, and astrophysics) plus references to a further eleven in text books, plus more definitions of specific types of entropy such as black hole entropy - and this before we even look at the Wikipedia article on entropy in information theory. By your standards, if the term ‘transitional’ is poorly defined, then the term ‘entropy’ is so ‘plastic’ as to be useless. But of course, physicists know what they mean by the context of the particular problem that they are addressing, just as palaeontologists and cladists do. You are creating a difficulty where none exists.
If Darwin agreed with you that “almost all fossils can be placed in a nested hierarchy” then he would hardly have considered the absence of intermediates a problem for his theory.
Are you suggesting that there have been no advances on palaeontology and evolutionary biology for over 150 years?
The article you referenced contained this: "It is a genuine transitional … Never let creationists tell you that there are no transitionals." If, as you claim, almost everything is a transitional, this statement is incomprehensible.
I didn’t reference it. I wrote it. I am the author of the article. I don’t see why you think the statement is incomprehensible - it is perfectly comprehensible to me. It is a fact that creationists claim erroneously that there are no transitional fossils, and it is a fact that they exist, so the statement makes perfect sense. Obviously some transitional fossils are more significant than others - not many people outside the trade are interested in the transition between two relatively closely connected and obscure groups of, say, ammonites in the upper Permian. But the discovery of transitional fossils in the transition, say, from fish to tetrapods is important and interesting both to scientists and the general public. I wrote the article (describing Nakabichi et al’s paper) because this particular case is interesting - a transition not between one organism and another, but between an organism and the integral part of a eukaryotic cell. The work of Margulis and others has resulted in a general acceptance that eukaryotic organelles derive from free-living bacteria. If that is so, then there must have been a gradual transition - a time when the bacterium had characteristics of both a free living organism and an organelle. Here, in Carsonella rudii, we see a thing on that path, showing that that stage of the transition exists in nature. I found that interesting, but obviously you don’t.
This is from Wikipedia: “It is commonly claimed by critics of evolution that there are no transitional fossils. Such claims … may be a tactic actively employed by creationists seeking to distort or discredit evolutionary theory.” Again, if the record is overflowing with intermediates, such concern with creationist objections is paranoid.
On the contrary, since creationists do make this erroneous claim, frequently, and since the general public, ignorant as it is, is often taken in by that nonsense, why should scientists not refute them? To point out that something is utterly wrong is not to admit that it might be right. The existence of transitionals is not a scientific debate, but a question of the public understanding of science.
What I object to is that having these discussions is like trying to put your finger on a ball of mercury: the target shifts and occupies some other space as soon as you try to nail it down. Why aren’t there precise definitions for the terms being argued?
That might be because of *your *unwillingness to ground the discussion in specifics - you might well be the cause of your own confusion. I don’t see that there is any difficulty in understanding what a transitional is. I have asked before - what is it that you think is lacking in the evidence that you would like to see?
Alec
evolutionpages.com
