I'm not sure I understand your question. What I see is obvious genetic drift, a founder effect. It could very well be temporary situation for this population or a result of habitat fractionation, but it could also be a strategy for overall survival. And when I say temporary I mean in a geological sense, these canyons were carved out by glaciers roughly 10,000 years ago, so I doubt the snakes lived there then. The habitat is very harsh here, and very likely they can only survive the winters in very specific locations.

For that reason I imagine that there is intense competition for these key locations to survive. Also there were recent major disruptions to the habitat (last 40 years the building of 4 dams and the inundation of 100,000's of acres of this key habitat, turning it into several reservoirs.) So when all the right elements are in place for survival and the food supply is there, I do not believe these snakes go very far at all. However when those resources dry up or they are forced to move (floods, glaciers, ect) then there is significant gene flow. Other than that not so much.

I would imagine the Fl landscape has very similar disruptions quite commonly with the high frequency of hurricanes, causing major disturbances in population dynamics and geneflow ect, not to mention all the other major recent disruptions such as shopping malls and condo's and such.

My guess is there is a lot of two extremes right now. Small inbreed populations that are isolated, and huge melting-pot type populations that get lots and lots of migrants all the time from various escapes from these isolated populations. However I think that is a temporary state for a population to be in as well. It just depends on the current environmental conditions.

What I have is one very clear example of real data though, and not some imaginary theory. All kinds of speculations can be drawn from the data.









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"Relax, Don't Worry, Have a Homebrew!" Charlie Papazian

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