[Taxacom] Dispersal... again

[Jason Mate]

Hi Michael,
As I am off now to the field til tuesday I think we all have time to think our rebuttals carefully as this discussion is getting us nowhere.
?MH: No, it's completely different. The new model is opposed to the modern synthesis model and in many ways is derived more directly from the geneticists, i.e. the original geneticists such as T.H. Morgan (Nobel prize for genetics but ridiculed in the modern synthesis for not understanding genetics). The earlier workers saw the direction of evolution as due to mutation, in the modern synthesis it is due to selection and adaptation. The new model has very different interpretations of these key concepts, as well as 'gene pool', and all the others.  Michael Lynch has an interesting 2007 book: 'The origins of genome architecture'. These broad genomic changes can be happening throughout a population (e.g. broad shifts in CG composition), not because of random mutation in an individual followed by gene flow, adaptation and selection. ?
Michael, I really don?t know what you are leading to. Morgan was the leading figure of genetics with a Nobel to boot for ?solving? inheritance (chromosomes as the units of information), so yes we agree he was a big fish (also popularized D.melanogaster as the workhorse of genetics). What I don?t understand is why you say he was ridiculed (and by whom). He rejected sexual selection, so this could be the source of some criticism, but by and large the man was a neodarwinian. His ?A Critique of the Theory of Evolution? supports Darwinian Selection, supplying the rather important piece of inheritance, without which it was fatally flawed. Furthermore he stressed the importance of mutations in the same vein as other He invited Dobzhansky as a foreign researcher, the same Dobzhansky that wrote the seminal ?Genetics and the Origin of Species?. Morgan even suggested the title! The book is practically the synthesis. It just needed Mayr, Gaylord Smith and others to give it mass appeal (OK Fisher and Haldane made important contributions but Dobzhansky is the true father of population genetics and the modern synthesis), establishing populations as the units of evolution, balancing selections (natural selection, mutation, migration, drift..) as the forces that resulted in genetic variability (this variability was the Achilles heel that De Vries, Johannson and other anti-darwinists attacked!). So once again, Lynch is not postmodern synthesis but additional work in population genetics.  MH: you seem to have missed out something here - 'sympatric'?? I think he was correct to dismiss sympatric speciation. Most supposedly sympatric groups actually show high levels of allopatry and the area of sympatry probably represents secondary overlap. The limnetic and benthic forms of three-spined sticklebacks in the British Columbia lakes turned out not to form monophyletic pairs in lakes. Instead, they are related to limnetic and benthic forms, respectively, in other lakes. The two forms didn't evolve by sympatric speciation within a lake but diverged before their secondary overlap (e.g. caused by marine flooding).  
Cichlids, Rhagoletis pomonella, the  Enchenopa binotata complex...
  ?MH: Yes, it was an oversight. Relying on chance to explain spatial patterns in evolution meant that large parts of the modern synthesis were flawed at the outset. (It's not just 'my version' of vicariance - it goes back to Hooker and Huxley and is now used in many publications).?
You mean like Croizat using Kepler as his mirror, his philosophical buddy? You cherry-pick to support a case that doesn?t exist. There is no nemesis!
??So, going back to dispersal, I have some questions to ask. How does a species achieve a ?wide range? if not by spreading out from somewhere? Doesn?t this entail an initially smaller range?MH: If a mirror is struck by a hammer (vicariance), the individual, broken shards do not move to their current position - they 'evolve' in situ, by the fracturing of a larger entity. ??
So the mirror appeared from nothing? The pieces do not expand? No piece is a single population? So if I break your mirror over and over I end up with an infinite number of singleton species? Michael the logical fallacies are written all over. Your insistence in only recognizing vicariance pushes your arguments into corners from which the only escape is making illogical arguments or worse, vaguely defined terms that sound like something else but aren?t unless you have trudged through the Croizat Bible. Just look at your stance on speciation:
?MH: I'd say speciation occurs after the groups are subspecies and before they are subgenera.? 
Don?t you mean populations? Why bring in subgenera or subspecies? Is it because Croizat can?t work with populations? You create a myth that the modern synthesis doesn?t recognise forces other than selection (just Dobzhansky?s papers will put this to rest) and then happily parade Croizat? ??MH: I accept dispersal but not 'chance dispersal'. They accept both and think of them as the same process.?? ??MH: I don't take issue with it. The point is he did not apply this principle in practice, to his analyses of actual groups. This was written in 1976, a couple of years after critique of his work had begun ??to appear in journals such as Syst. Zool. ????MH: I think it defines his ideas in a clear and succinct way. I've read most of what Mayr wrote, including dozens of his early papers.????MH: I'm interested in Mayr only as the source, the type specimen, of the current ideas - most people accept the modern synthesis as basically correct, give or take sympatric speciation, founder effect speciation etc. ??
What is it. I have told you repeatedly that Mayr recognised the influence of both, as have many before and most since have. Yet you call them ?dipersalists?. Well, I thank you for your 1982 Mayr article in the Auk, as it was very instructive:
?That there are different causes  for  distributional  discontinuities  was  known and  extensively discussed long  before  Croizat's grandfather was born. Most of  the earlier authors realized  that  there  are  two  kinds  of  discontinuities: (a) primary ones produced by the establishment of a founder population across a geographical barrier, and (b) secondary ones, caused by the disruption of a previously continuous range by a geological event (a fracture of plates, a flooding of shelves, the rise of a mountain range, etc.) or by  a climatic event (ice barrier, origin of savannahs or deserts, etc.)?
Please tell me how vicariance is not mentioned, in equal footing, in this quote. (for those interested the article can be found in this linkhttp://elibrary.unm.edu/sora/Auk/v099n03/p0616-p0622.pdf)
Best
Jason