Posted by:
CKing
at Sat Apr 19 00:55:59 2008 [ Report Abuse ] [ Email Message ] [ Show All Posts by CKing ]
>>KC, >>Thanks for the input. >> >>At the time, the senior author was not aware that the dwarf morph occurred throughout S. Calif. and not solely in the San Bernardino and perhaps San Jacinto Mts.
That explains a lot about their taxonomic proposal. Thanks for the information.
>>The authors thought there was a sweet of characters that with reasonable confidence, one could readily distinguish between Southern and Northern Rubber Boas. That turns out not to be true if one is comparing the boas of the southern clade from the San Bernardino Mts. (and presumably from the San Jacinto Mts. which have never been studied) with members of dwarf populations from elsewhere in S. Calif. This is especially the case for the boas from the Mt. Pinos region which are extremely close in all respects to the boas in the San Bernardino Mts. except that the mtDNA results indicates the Mt. Pinos populations belongs to the northern clade.
mtDNA data is merely distance data, which means it is a measure of how long ago two populations last shared a common ancestor. As biologists (including Charles Darwin) have known for a long time, some species and some populations evolve much more slowly than others. For example, we all know of such species as the coelacanth, which has changed very little over hundreds of millions of years. The fact that the Kern County boas are part of the "northern clade" may simply mean that these animals have become isolated from their southern populations geographically for a long period of time. Their similar morphologies would appear to me as the result of "stasis" or no change from the ancestral condition. Should we then classify a population as a different species or subspecies, despite the lack of change, simply because it has become geographically isolated from the ancestral population? The answer is no to a vast majority of biologists. Evoluton means change. Changes in the mtDNA is not evolution, since these changes are the result of random mutations which do not affect the fitness or survival of the species.
>>Although the paper stated that the Northwestern and Sierra subclades were allopatric with the break occurring in the Mt. Lassen area, that is incorrect as there is no break whatsoever in the distribution of the species from northern Kern County all the way to British Columbia and east to Montana, Wyoming ,etc. >> >>Richard F. Hoyer
I assume you have unpublished data to show that the boas occur within the break. If so, it is very interesting and it should be published. The mtDNA data of these animals should be obtained to see if they belong to the coastal lineage or the Sierra Nevada lineage or both. If both types are present, it does not mean that they are interbreeding because mtDNA is passed on only from mother to daughter. Other types of data are needed to determine if they are both present and whether they interbreed. This data could help us solve the problem of Rubber Boa taxonomy. Regards.
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