John A. (Salty) Davison - The Case For Instant Evolution

Yep, it is at least theoretically possible. The only requirement really is that the suite of traits or phenotype of the hypothetical hopeful monster be able to survive a period of polymorphism with the other phenotypes of the species until it becomes fixed as part of the population. I can't think of any examples outside of plants at the moment, but I'd be willing to accept that there are some.

I would be interested in hearing Dr. Davison's explanation - or clarification - concerning his statement on karyotype comparisons between species. How does this statement relate to karyotype differences within species? For example, Mus musculus domesticus is an interbreeding species which contains several different karyotypes due to recent Robertsonian fusions, the same kind of fusion that resulted in one chromosome fusing from two in human ancestors - the primary difference between human and chimp genomes. In Western Europe, there are 13 different standard karyotypes in mice. Along hybridization zones, there are even more karyotypes created by breeding between the standard karyotypes - 24 different karyotypes can be found just in the Alps. There is extensive interbreeding among the various karyotypes, and no evidence of serious reproductive barriers. Stating that different karyotypes are all-or-nothing and irreversable seems contraindicated by observation. It would also appear that these karyotypes represent "intermediate forms" of the mice.Refs: Castiglia, R and Capann, E wrote a series of three articles for the journal Heredity describing this observation:Contact zones between chromosomal races of Mus musculus domesticus. 1. Temporal analysis of a hybrid zone between the CD chromosomal race (2n=22) and populations with the standard karyotype.
Heredity. 1999 Sep; 83:319-26Contact zone between chromosomal races of Mus musculus domesticus. 2. Fertility and segregation in laboratory-reared and wild mice heterozygous for multiple robertsonian rearrangements.
Heredity. 2000 Aug; 85:147-56Contact zones between chromosomal races of Mus musculus domesticus. 3. Molecular and chromosomal evidence of restricted gene flow between the CD race (2n = 22) and the ACR race (2n = 24).
Heredity. 2002 Sep; 89:219-24.There are a number of other organisms that demonstrate such staggered clines based on karyotype differences, but that will be enough to go on for the moment.

Hi Salty,Sorry I didn't get a chance to get back to you sooner. I'm aware of what you wrote in the Manifesto. That wasn't the thrust of my question. I was not discussing speciation OR primate phylogeny. I was specifically asking for clarification on your statement (from the OP): "The reorganization of a chromosome is an all-or-none event for which intermediate or gradual stages are inconceivable." The clarification seems to be required because observation of different karyotypes within species - which can justifiably be considered intermediate and/or gradual stages of pre-speciation through allopatry - would appear to disconfirm a major assumption of your theory. Especially if there is evidence that karyotypes can and do recombine where clines overlap as was demonstrated in the well-studied M. musculus references I cited.Sorry if I wasn't clear.

Perhaps you should explain what you mean by "all or nothing". I understand what you wrote about the unliklihood of reversal of chromosome fusion (for example) in the Manifesto, but it does seem to be refuted by the existence of clines with functional hybrid zones between different karyotypes. However, you go on to state: This is flat out in error. Here are a few examples: Incipient species formation in salamanders of the Ensatina complexChromosomal inversions and the reproductive isolation of speciesSexual selection and speciation in field cricketsGenetics and the Origin of SpeciesBiodiversity of Costa Rican salamanders: Implications of high levels of genetic differentiation and phylogeographic structure for species formationAnd of course Irwin's study of the Ensatina salamander ring species (sorry, I don't have an on-line version) Irwin, D. E., J. H. Irwin, and T. D. Price. 2001. "Ring species as bridges between microevolution and speciation." Genetica 112-113:223-243. Apparently, you are incorrect. I haven't even discussed plant speciation - which can happen in a single generation through polyploidy.

Well, before you leave evcforum in disgust or head to Stockholm, I'd appreciate it if you'd answer the questions and address the evidence I posted for you in message number 85 of this thread. Thanks.

You mean this utterly trivial observation is your entire point? Okay, no argument. Something happened or it didn't. Duh.However, you have failed to address the substance of the post. How does the semi-meiotic hypothesis address the well-documented observation of the existence of differing karyotypes in populations (for example, in ring species), with a functioning hybrid zone, that over distance show graduation to completely different species? Your assertion that speciation doesn't occur seems contraindicated by this phenomenon - after all, there is a very limited amount of change between one metapopulation/population and another (hence the ability to hybridize), which refutes your argument that gradual change can't occur - that only instant speciation is possible in sexually reproducing species. Please address the references I posted for you. After all, if you expect people to read YOUR papers, I would expect you to read the papers people post in reply.

Possibly, however you have as yet failed to actually provide an example of these "intrinsic factors". It could be that the reason no one has devised a way to test for them is that they don't actually exist. Actually, the reason there isn't any point in recommending de Grasse is because his entire work is based on a discredited concept - lamarckian evolution. Beyond clonal or single-celled organisms subject to conjugation, etc, lamarckism isn't what is observed in nature. That's nice. Now, do you have a single, solitary example from an actual organism that this occurs or has occurred? That's all anyone's asking of you: provide a concrete example rather than spurious rhetoric, handwaving, or gratuitous insults. Or apparently even the most fundamental, "real world" observation that your hypothesis rests on anything more than empty air. Well, I suppose if you want to look at it that way. On the one hand there are multiply converging lines of evidence from dozens of disciplines that indicate the "darwinian hypothesis" (whatever that is) is a pretty good explanation, and on the other we have you, with no observations and no evidence. I'm not sure I'd characterize that as a mexican standoff. Not at all, although it's certainly possible to call your "predecessors" conclusions into question. The only thing anyone has asked you to do at any time on this forum is simply provide some argument, evidence or observation in support of your idea. That's all. When you resort to attacks on individual posters, spurious appeal to authority, and special pleading, guess what? You'll get back the same tactic. It is also very revealing that only in the even smaller forum where you apparently lurk are you comfortable in knowing none will question your "genius". As far as being afraid to mention discredited scientists or theories in published papers - why should they be? The theories have been superceded or discredited long ago. Why should they be mentioned? It isn't fear - it's the fact that science has moved on, and the authors you're so taken with have been shown to be in error on key elements of their ideas (saltationism from Goldschmitt - although I think he got a raw deal, because aside from the instant speciation, he made some good observations - and lamarckism from de Grasse.) So they're not being ignored. They're simply irrelevant. I don't know. The fact that you haven't seen fit to provide any evidence or even discussion makes it hard to find anything favorable to say about you or your theories.[This message has been edited by Quetzal, 03-25-2003]

I have read it - all the way through. I have called you on your mis-statements concerning both instant speciation vs gradualism, and karyotype differences between populations as evidence of said gradualism. I have provided several references to support my contentions. You have, as yet, failed to even address any of my comments. The Manifesto presents no facts at all - merely assertion, special pleading, and appeal to authority. You have been asked repeatedly by me and others for specific examples or observations to support your theory, which you have failed to provide. End of story.