Cladistic ?

Cal, This is one subject on which we somewhat agree. Some strict cladists, whether they will admit to it or not, have used their positions as editors, reviewers, and 'funders', to impose their views on the rest of the scientific community

Cladograms were invented by, of all people, Ernst Mayr. There is nothing inherently unsound in the construction of a cladogram. Constructing a cladogram using shared derived characters is not an invention of cladistics. The real difference is that the cladists think that cladograms are 'discovered.' Hence they treat cladograms not as a hypothesis of relationships, but some sort of unchallengeable, objective truth.

Virtually all of the 'innovations' of cladistics, e.g. weighting all characters equally, ignoring character goodness, etc., serve to undermine the soundness of systematic analysis. About the only improvement they made is speed in the construction of a large number of tree permutations, through the use of computers. But then a high speed computer does not make one a better systematist, not any more than a high speed computer can make one a better designer of optics.

The bad cladists simply ignore the wisdoms of great systematists past and present. They will not listen to any criticism, constructive or otherwise.

They don't need any encouragement. They think their cladograms are unchallengeable, objective truth. They think they have a superior method, period (or full stop if one is British).

I am sorry. Cladistics is not the baby, it is the bathwater.

I agree, the war has gone on for too long but it is a war that is entirely the fault of the cladists. They started it, and they have never stopped their war on systematics. The cladists will keeping up their destuction of the existing classification with their war on systematics. The latest salvo is the 'Phylocode.'

I think the evidence is clear. Cladistics does not work, not when they resurrect such long discarded 'clades' as the loon-grebe-hesperornithiform clade, the owl-hawk clade, the Dinosauria clade, and the bird-theropod clade. I don't know whether I should laugh or cry when I see such nonsense as 'avian theropods' in otherwise first rate biological journals. As Feduccia (1999:398) points out, 'cladistic analysis...shows again a tendency to revert to systematics of overall similarity that dominated the eighteeth and nineteenth centuries.' Cladistics is hardly scientific progress, unless you think that progress is going 'back to the future.'

I don't like to mention the cyberstalker, but his/her presence is real. He/she will just come back again and again with new toilet paper (=discard when soiled) identities to annoy me. Neither cladistics nor the cyberstalker is going to go away any time soon.

Cal, You sound like a politician the way you generalize about cladists. There are so many different kinds of cladists now that I have lost track. Some cladists, like Nixon and Carpenter, apparently don't like the PhyloCode either. Hardly a monolithic group on which you can attach simplistic labels. I still believe moderate eclecticists and moderate cladists can eventually forge a common cladisto-eclectic approach to systematics, but extreme eclecticists (like yourself) and extreme cladists would probably prefer to see the war continue. I've never heard of Ernst Mayr being the inventor of the cladogram. Where did you get that piece of information? Ken Kinman

John, I haven't seen the Nixon and Carpenter paper yet, but a colleague of mine in France (who knows the Kinman System very well) told me about the paper in Cladistics and thinks that some of their ideas and mine are not very far apart. So will have to get a copy and study it carefully. Therefore, I can't yet say if I would be appalled at parts of it or not. And I should mention that the Kinman System is basically a cladistic system (the main coding is cladistic), but modified to allow the recogition of occasional semi-paraphyletic groups without the loss of any sister group information. It therefore has many advantages that traditional cladistic classiications (as well traditional eclectic classifications) lack. In retrospect, perhaps I should have called them semi-holophyletic groups, rather than semi-paraphyletic. Many cladists have a gut reaction to reject anything remotely related to paraphyly, so they don't even give any thought to the possibility that purely cladistic classifications could be modified for limited paraphyly without losing any cladistic information. But I've been between a rock and a hard place all along, because cladists think I'm too eclectic, and eclecticists think I'm too cladistic, and most of those with strong feelings on either side have long been indoctrinated with the notion that it has to be either 'their' way or 'our' way, and never the twain shall meet. Obviously, I think it is not only possible to create such a system, but that it is advantageous over other systems in a variety of ways.

Ralph Nader and Pat Buchanan are both politicians and presidential candidates (neither of whom I will vote for BTW). Yet I can't fathom what, if anything, they may have in common. So, I am not sure how a politician may sound like.

True. There are of course the pattern cladists, who deny——of all things——that 'the pathway of evolution is knowable and also deny that their analysis has anything to do with the exploration of phylogeny' (Mayr and Ashlock 1991). OTOH, some of the 'hard-line' cladists claim that cladograms represent unchallengeable objective truth that are replaceable only with a more parsimonious cladogram. So it appears that the cladists themselves are more like a group of politicians with opposite extremes in their philosophies.

Sure, some cladists also tolerated paraphyletic taxa. But these cladists were themselves viewed with suspicion and were considered not part of the 'core cladists' because of such heretic behavior. I think the definition of numerical taxonomist who adheres to Hennig's principle of monophyly is a pretty good description of a cladist.

And what may that approach be? Is it similar to being slightly pregnant?

No, I just like to see an end to the war waged by the cladists on traditional systematics. Destruction of the existing classification——the real goal of the cladists' war——is not a good thing for biology or science. Neither is the cladist's return to pre-Linnean facile diagnosis.

I have forgotten where I first heard about it, but I think it is a pretty accurate claim. After all, a cladogram is nothing more than a phylogenetic tree with the information concerning ancestor-descendant relationships removed. Hennig did not invent the use of shared derived characters to hypothesize branching order, and cladists were surely not the first to claim that ancestors may be forever unknowable. In fact, Mayr and Ashlock point out that not one single ancestor of a higher taxon has been identified, and that owing to the incomplete fossil record, ancestors may be forever unknowable. And because of that reality, it is simply unrealistic to define taxa on the basis of a forever unknowable ancestor and all of its descendants. A more pragmatic approach is a definition of monophyly that only requires an ancestor of a higher taxon must be another taxon of equal or lower rank. Hence the reptiles are a monophyletic group if it is descended from the amphibians because Amphibia is a taxon of equal rank to the Reptilia.

What a great quote! 'My cladogram is unchallengable truth! That is, until someone challenges it with a better one....'

When someone churns out a statement like the above, they've clearly been working too hard.

Cal, The comparison to politicians was to point out that (like them) you overgeneralize and exaggerate the perceived shortcomings of your opponents. This should not be done even with the most extreme group of cladists, much less with 'cladists' as a whole. There are plenty on each side (eclecticists and cladists) who do facile diagnosis and the other generalized things you discuss. As for the Kinman System (a cladisto-eclectic system) being compared to being partially pregnant, such a simplistic analogy (which I have heard before) is just reflective of the widely-held notion that cladism and eclecticism are incompatible and necessarily mutually exclusive. It's that kind of 'us versus them' attitude that keeps the war going. If you don't believe solutions are possible, you won't look for them, and that reinforces the belief. It's a vicious cycle that I'd like to see broken.

Thank you. Perplexing though it may be, that is exactly how the cladists behave.

I am not the only one who noticed this sort of anomalous behavior.

'The problems with cladism may be summarized as follows: .. vi) A concerted drive to assert with finality (or at least until the next hypothesis) that which one does not actually know.' (Pritchard, P.C.H. 1994 Cladism, the great delusion. Herpetol. Rev.)

Pritchard observes that cladists hold on to their cladograms tenaciously and ignore all crticisms. And yet they may readily abandon it when they do a new analysis.

Reading Chiappe et al.'s reply to Zhou in The Auk regarding Mononykus, one can see it in action. They treat their cladogram as though it were unchallengeable truth, since they ignore Zhou's point that Mononykus does not have a single uniquely avian character and they claim that a cladogram can only be replaced with another more parsimonious cladogram. IOW, no cladogram no talk.

If Keesey thinks that such behavior is paradoxical, I do not blame him. That may be one reason the evolutionary systematists point out that cladism often takes on 'the overtones of religious dogma.' (Pritchard

I disagree. Cladistics is in fact a return to pre-Linnean facile diagnosis. No less an authority as Mayr and Asholock has pointed that out.

OTOH, if that is your definition of a politician, then the cladists have often been accused as being 'political.'

'The problems with cladism may be summarized as follows: i) 'Straw man' arguments that misrepresent the actual nature of competing approaches to systematics. ii) The absence of new concepts behind the new and opaque jargon. iii) Deliberate rejection of 'hard' data, and incompatibility with the fossil record. iv) The erroneous axiom that evolutionary history has been simple and overwhelmingly divergent (the principle of parsimony). v) Subjectivity masquerading as objectivity throughout the discipline of cladistics...' (Pritchard 1994, Cladism: the great delusion.)

There were indeed many traditional systematists who used facile diagnosis, but their hypotheses were largely refuted by others who subsequently employed detailed comparative anatomy. An example would be the loon-grebe and owl-hawk clades. These taxa were abandoned when their similarities were shown to be convergent. However, refuted hypotheses like these have been resurrected by cladists time and again.

If you don't like the slightly pregnant analogy, I wil give you another one.

The cladists have a bulldozer, and they want to level the house of Linnaean classification. The Kinman system is a modified bulldozer that is a little less destructive. It will spare, say, the chimney while leveling the rest of the house. The hardline cladists say that the chimney cannot remain. It must go with the rest of the house. The traditionalists, OTOH, find little consolation or use for a chimney without the house. They want to save the old house because it has served biologists well for centuries. There simply is no room for compromise.

Cal, Au contraire. The Kinman System does not bulldoze anything. It has *remodelled* the house of Linnean Classification, and knocked out a few unnecessary walls. This remodelling was done to convince cladists that it should not be bulldozed. Eclecticists should also find it a nicer house to live and work in. Sorry if you wanted to keep the old Linnaean farmhouse the way it was, but I thought it was about time to install some electrical wiring and indoor plumbing. Got to keep up with the times or it will fall into disrepair and definitely get bulldozed.

Well, if someone is willing to accept falsification (or dubification) of their previous findings on the basis of new data, how can you claim that they believed their previous findings to be 'unchallengeable truth'? Obviously they were open to it being challenged, and when it was challenged, accepted the newer view.