Extent of Mutational Capability

I think you misunderstand the Biological Species concept... it does not state that different species cannot produce viable offspring under any circumstances; it states that species are groups of organisms that interbreed in nature and are reproductively isolated from other such groups. So... lions and tigers ARE separate species since they do not interbreed in nature - even though they can be forced to do so in captivity. So is the case with most of your other examples of separate species interbreeding.Yes, of course there are problems with species concepts, for example, the Biological Species Concept does not apply to clonal organisms. There are complications when determining where the boundary between two species is - since there is more a continuum between species than there is a hard boundary. This is kind of true. Classification of species is a human endeavor with the purpose of making communication about biological life more precise. When a new species or a reclassification of a group is is proposed it comes with solid reasons/evidence for the new classification. Often times the proposal is argued about in the literature for years until a consensus is reached. But again, all this is done with the purpose of making communication about the organisms more effective."Kinds" is a completely different concept. The purpose of defining "kinds" seems to make communication more ambiguous. There is just no rigorous methodology for determining "kind." Notice how open-ended the following definition is: How could you possibly determine that they could interbreed immediately following creation. This definition is completely unusable. A better, but still problematic, definition would be that each pair of animals on the ark represented a "kind." Still, how could that help communication?What Creationists want to accomplish by proposing definitions of "kind," despite their common rhetoric, is to discredit evolution - not to provide a better understanding of how nature works. Even more important is to establish that man is a separate "kind" and did not evolve from "lesser" creatures. These goals do not advance our understanding of how life works, they only serve to establish that a particular interpretation and understanding of scripture is correct and infallible and that the intention and thoughts of a people long gone are so clear to us. That is why the concept of "kind" is not considered scientific, but a form of apologetics. Why is that not the nature of theology as well?HBD

True. But he can't claim that one "kind" has never been observed turning into another "kind" without a working definition, because we would have no way to determine if the statement was correct.HBD

But Greg's question is essentially "are there genetic limits that prevent one kind of creature from becoming another kind?" So without a useful definition of "kind" it is pretty hard to really address that question. For example, are wolves and foxes different kinds? Well, lets see... were they able to interbreed immediately after the creation? How could you possibly determine that?I think RAZD's definition is very good: "A "kind" would then be a clade with no previous ancestor." This can be determined and discussed. If I pointed to any living or fossilized organism and asked "what came before this organism?" The answer would be "a similar organism. Not one that was exactly like it, but one that was slightly different." So it is a perfectly valid assumption that every organism and every group of organisms has a ancestral organism or group of organisms. It then becomes an hypothesis as to what those ancestral groups were, but the assumption that there was an ancestral group is quite valid.**There is just no scientific reason why we should assume that any clade should have no previous ancestor.However, you are arguing that some clades do not have previous ancestors and that the founding group of that clade was the original interbreeding population at the time of creation. So that is what you need to offer support for. What clades have no previous ancestor and what evidence supports those hypotheses? Failure of two species to produce fertile offspring does not indicate they are members of separate clades without a common ancestor since we have species that do not interbreed that are clearly part of the same clade.Defining the term "kind" as "those animals/plants that could interbreed immediately following creation" is a moving target type of answer; it can be stretched and fit to any hypothesis you wish to propose since there is no way to determine what "kinds" even existed immediately following creation, let alone if they could have interbred.HBD

This is definitely the best definition of a kind I have ever seen. It is exactly what a "kind" would be. I don't think creationists will be too likely to adopt it though since it is too unambiguous and they need the definition to be adaptable to be able to fit any preconceived notions they have - such as humans which clearly have ancestral populations and so would not be considered a "kind" without including some very "non-human" hominoids.HBD

I have to correct you on this, RAZD; someone else also said something similar a few messages back, but it is not really correct. Cladistic analyses have three basic assumptions:1. The groups being studied are related by descent from a common ancestor
2. The pattern of cladogenesis is bifurcating
3. Changes in character state occur in lineages over timeSee: http://www.ucmp.berkeley.edu/clad/clad1.htmlA cladistic analysis will always create a bifurcating tree where all organism being studied are related. So cladistics does not test to determine IF they are related but rather HOW they are related. This cladogram is then the hypothesis as to how the organisms are related and possibly how a particular character has evolved.ABE: The congruence of independent cladograms is the strongest evidence for common ancestry /ABEI like your definition of a "kind" though, which would be a clade without an ancestor. I don't think cladistics would be able to directly determine if a clade did not have an ancestor, but we could hypothesize about relationships between unrelated clades and use distantly related clades to test those hypotheses and then see if we see those types of patterns when testing larger groups.I haven't given the idea of looking for clades without an ancestor much thought, though... understandably. It seems as if there would be a obvious signature of "kinds," but no one is really looking for it. I would need to give it some more thought as to what that signature would actually look like. But as far as I know, there is no test to determine IF a group has an ancestor, only what that ancestor might be.ABE: Perhaps clades without an ancestor would not provide consistent results through different phylogenic reconstructions, at least in relation to other groups. Although I don't know that this would be a slam dunk. /ABEHBDEdited by herebedragons, : Additional thoughtsEdited by herebedragons, : No reason given.

No, it's not false. Maybe you think I am using the term 'assumption' to mean "wild-ass guess with no evidential support." But that's not how I am using the word 'assumption.' Actually, I am glad you brought this up because it is an oft misunderstood term. In a scientific context assumption means:"a premise that must be true in order for the test and resulting conclusions to be valid."While this definition is not a standard dictionary definition, I think it best reflects how we use the term when doing scientific research. It is important that we recognize what our assumptions are and are able to justify them. In one of my classes recently, we were talking about a particular line of research and how it could be more transparent. My response was that researchers need to be more open about the assumptions they are making and what the weaknesses of those assumptions are. Otherwise it can be a bit deceptive. Not a valid analogy. By the very nature of a phylogenetic/cladistic program, a dendritic tree is generated with the following qualities:a) the subjects being studied are related by descent, ie. they share a common ancestor
b) each character state change is depicted by a branching event called a node
c) the subjects are grouped by shared character state changesThis is HOW phylograms/cladograms are built; there is not other ways to build them. In order for this to work, you must start with the premises (assumptions) I listed above. If this were a true test of common descent, then the trees could be built in ways other than a bifurcating, nested hierarchy; but they can't. They can ONLY be built as a cladogram/phylogram. Can you see how this would be circular reasoning? You group subjects into a cladogram to see if they form a clade.Think about it, let's say I do a phylogeny of 10 fungal species, 10 primate species, 10 fish species, 10 bacteria species and 10 reptile species. Would that really be a test to see if they shared a common ancestor? They would probably even have a very high confident index since there would be little homoplasy. But let's say reality is that they ARE separately created "kinds." A cladogram would still group them into a bifurcating tree with common ancestors because that's what cladograms do... Cladistics is a test of a particular hypothesis about HOW a particular set of taxa are related. If trees were unreliable, inconsistent or have low values of phylogenetic signal that would be an indication that one or more of our assumptions are violated.So, in a way, cladistic analysis IS a test of common ancestry, but through confirmation of the assumptions and not in and of the cladogram itself.ABE: If you don't agree with my list of assumptions for cladistics, perhaps you could describe what you believe the assumptions of cladistics actually are? /ABEHBDEdited by herebedragons, : No reason given.

I didn't say common ancestry itself was an assumption, I said that common ancestry is a basic assumption of cladistics. Not really. The outgroup establishes the ancestral character state. Since cladistics is based on synapomorphies (shared derived characters), it is important to establish what the character state was originally (which relies on the assumption that there IS an ancestral and derived character state). Simply put, because that is how cladistic programs are designed to work; they can't do anything else. Oh definitely! Many aspects of biology are best explained by common descent. But that is a different point than I was making.In order to do a cladistic analysis, you start with the basic assumption that the subjects are related by descent. This doesn't diminish the validity of common descent, it's just being honest about what our base assumptions are when doing cladistics.You wouldn't be able to build phylogenies that were consistent with separate lines of evidence (such as paleontological evidence or disparate morphological and molecular data) if they were not actually related by common descent. But this would indicate that one or more of our base assumptions are not valid; it wouldn't be because a cladogram could not be constructed.See my response to Taq in Message 128 for a little more discussion.HBDEdited by herebedragons, : clarification in last paragraph

I agree that it's weird that the authors knew who the reviewers were, but maybe that journal's policy is not anonymity. (?) Most reputable journals do have a policy of reviewer anonymity though, so it is definately suspect. I doubt CRR is lying himself, though, he simply got this information from somewhere and is just repeating it. I think it depends on when during Sanford's career he reviewed it. I believe he started out as an atheist, then became a theistic evolutionist, then old earth creationist, then ID, then YEC (which is unusual in itself).What bothers me is that they submitted it to a quite prestigious journal, with a pretty narrow focus and when it was rejected, they went ahead and published in a creationist journal... Anyone who has submitted anything for publication knows that even good articles can be rejected for various reasons not related to quality or accuracy. What most researchers do is submit to other reputable journals until someone picks it up, not go right for a junk journal. So you fix it up and/or submit it to another journal, not dump it in the Journal of Creation That's what is smelly about it to me.However, not completely sure what specific article is being referred to here... I think I've look at it briefly, but I'm not sure. Maybe a link to the article? I don't think there has been any real discussion about it either... just that it was "essentially correct" yet rejected anyway (presecution complex?).HBD