>>Wolfgang:

>>Although I agree that the study in question is addressing a valid problem in the taxonomy of the Elaphe species, I think you have to question whether some of the branching shown will be the last word. As I stated in an earlier thread, some of the groupings with high bootstrap values (such as the new genus Euprepiohis) seem pretty well supported even on morphological and ecological grounds. But the higher order divisions have much lower values that will probably require additional work to confirm or refute. What I'm wondering is whether the current technologies will allow a more definitive study any time soon, or whether these questions will have to wait a generation for the next advance.



Hi John,



Current technology is certainly no obstacle, and since the authors of the study have the tissue samples, getting more data should be easy, subject to funding. I would certainly like to see them sequence more mtDNA genes, simply to make their tree more robust. Low bootstrap support is certainly a problem in that database. Another thing that is unusual is their choice of genes - COI is rarely used, most people use cytochrome b and ND4 as well as 12S and 16S. One consequence of the authors' choice of genes is that their sequences are now very difficult to integrate into existing sequence datasets. This is something that has bedevilled the history of snake phylogenies from mtDNA for a long time: everybody sequences different genes for different species, so if you look through GenBank to see what genes are available for what species, and biuld a spreadsheet with the relevant boxes ticked, what you end up with looks like a Swiss cheese. Obviously, I have no knowledge of the history of teh Utiger et al. study, what led to their choice of methods, and what the funding and employment situation of the participants is/was - it is always easy to criticise from a distance.



Another future direction they could and should take will be to sequence some nuclear genes - some nuclear introns should be perfect for that taxonomic level, and would provide an independent assessment of relationship, which different mtDNA genes cannot do.



Of course, in the real world, getting this sort of thing funded is difficult, and many good projects are terminated long before they have yielded their full potential, simply because the participants are unable to get the study funded, or becuase their employment contract expires and they are forced to move elsewhere. Few people working outside academia realise the extent to which these constraints influence the direction peoples' work takes.



As to the future of the Utiger et al. classification - I suspect many of the genera will stand more or less as at present, but doubtless, new data willproduce some new changes and discoveries. even then, let's not forget that the taxonomic conclusions of Utiger et al. are also based on the preious study by Helfenberger, not JUST on the mtDNA data. While one can always see how more could be done, I am happy to accept what Utiger et al. have done, simply because the evidence they have provided is considerably more convincing than the evidence for teh status quo. If new, more convincing evidence contradicts any part of their study, then that will have to be taken into account when it happens.



Cheers,



Wolfgang
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