I've got a calculus test coming up, and I'm trying to limit my time on the comp...



>>Polymorphism as I mentioned is generally considered a type of polygenic inheritance. I did not mean to imply that the two terms are synonymous. It's more like polymorphism is one type of polygenism.



Looks like we're getting into the realms of quantitative genetics...



I don't believe that polymorphism (e.g. as is seen w/ the variation of several traits of leonis kings, alterna and blairs phase of alterna, and the many appearances of Sonora sp. Ground Snakes) are good examples of the type of polygenic inheritance I believe Gray phase subocularis to be. I believe it to be, rather, an example of additive gene action, where several loci affect a single trait, and the alleles at these loci show no dominance, so the effects of the alleles on the phenotype are purely additive.



A better-documented example is that of kernel color in wheat, where a plant w/ dark red kernels is bred to a plant w/ white kernels...all of the F1s are an intermediate color (very light red); the F1s are then self-crossed, and all of the F2s show a gradient of phenotypes (some seven different shades) from white, to light pink, all the way to dark red.



Gray phase is a naturally-occuring color variety, much like Miami phase or Okeetee phase Corns. Gray phase often occur where the substrate is grayish. I've bred Orange phase, another naturally occurring color, to a yellow Blonde and got an intermediate-looking F1 generation. I haven't bred the F1s to count out how many alleles are governing the orange color (a very hard thing to do with a species that doesn't produce large numbers of offspring, quickly and repeatedly -- like wheat, for example). I believe the Gray phase is governed by the same type of polygenic inheritance, that is, additive gene action.



It could be an example of incomplete dominance, but I doubt it...it would seem that any locus that affects "Gray color" would be selected for in a species that needs to be cryptic, as they're both predator and prey. So, I think multiple genes are at play here.



Dusty Rhoads
Suboc.com

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