at Tue Nov 25 20:33:49 2008 [ Report Abuse ] [ Email Message ] [ Show All Posts by CKing ]
>>1) Beside occurring in the San Bernardino and San Jacinto Mts., a boa population of the Southern clade also occurs on the Southern Kern Plateau in southern Tulare County. >>
Hi, Richard. Thanks for the data. As I have pointed out before, the dwarf morphotype of the southern subclade (umbratica) is most likely the ancestral form of this species. This same morphotype is, according to your findings, found in the Kern County populations. That is evidence of stasis. The Kern County specimens have become isolated from umbratica for a long period of time without undergoing any evolutionary changes. Their mtDNA of course will continue to evolve, since these nucleotide substitutions are mostly neutral genetic changes that occur in a more or less clock like manner. The latest finding of an umbratica haplotype found in Tulare county is clear evidence that these two populations were once connected geographically. Of course they have to be because their mtDNA suggests that the Kern County animals are derived from the southern subclade. As I said before, the Kern County dwarf morphs should be included in umbratica, and umbratica should be treated as a subspecies of bottae, not a full species.
>>2) There is likely to be no break between the Sierra Nevada and Northwestern subclades as two specimens well south of the Mt. Lassen region from Butte County aligned with the Northwestern subclade.>>
That is an interesting result. It clearly is in agreement with the mtDNA findings of Rodriguez-Robles et al., which shows that the northwestern subclade migrated along the coast and at an earlier date that the Sierra Nevada subclade. It seems, then, that the Northwestern subclade has been able to move close to the northern limits of the Sierra Nevada subclade. It would be intresting to see if there is any overlap between the two. Until there is evidence of overlap, it remains an unanswered question.
>>3) Thirty-two samples with the same haplotype were dispersed from northern California to Oregon, Washington, B.C., Montana, Idaho, Utah, and I believe Nevada.>>
That is interesting but not unexpected. It certainly looks like the Northwestern subclade has been a very successful lineage and it again confirms Rodriguez-Robles data, which shows the Northwestern subclade is the first lineage to move into Northern California and beyond. If the Nevada specimens belong to the Northwestern subclade, then there was probably no back door migration of the dwarf morph Kern County animals in a northeasterly direction into Nevada.
>>The ramifications of point #1 above are extensive and intriguing.
>>Richard F. Hoyer
Finding #1 is interesting indeed. It remains to be seen whether this population migrated to Tulare recently, or whether it is a remnant of an old lineage. It is also interesting how much difference there is between the mtDNA of this population and that of the SRB. As I pointed out before, all of the populations of the SRB have similar mtDNA, suggesting a recent divergence and expansion from a small population, probably within a small refuge. My guess is that the Tulare County population is a much older remnant of the ancestral bottae population that made its way a long long time ago from the south. Again, very exciting new findings that fill that gaps of Rodriguez-Robles' data. It shows that Rodriguez-Robles et al. did a great job.
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