Perhaps of interest to some (but was never a Field Guide)...

[Don Ohmes <d_ohmes@yahoo.com>]

"Dogs have been our companions for thousands of years. This long 
allegiance and our preferences for dogs with certain traits have led to 
an unmatched degree of morphological variation and an opportunity for 
geneticists to unravel how genes interact with selection to shape 
phenotypes. Recent work in this area has revealed much about the genes 
underlying specific traits, such as coat color, foreshortened limbs, and 
hairlessness. Boyko /et al./ have examined variation at over 60,000 
single-nucleotide polymorphisms in 80 dog breeds, African village dogs, 
and wolves. Interestingly, they found that the majority of variation 
among breeds was generated by just a few genomic regions of large 
effect. For example, they identified only six regions associated with 
body size, and ear floppiness was associated with just a single region. 
They hypothesize that the small number of regions controlling such a 
large degree of variation is probably due to the repeated bottlenecks 
dogs went through in their evolution, first when they were domesticated 
and then during breed development. Genetic diversity measures support 
this hypothesis, as all breeds displayed much lower genetic diversity 
than either wolves or village dogs. --/PLoS Biol./ *8*, e1000451 (2010)."

A genome selected to be morphologically plastic, Fido is... albeit 
artificially.

This could happen "naturally" as well. A basal genome that is driven by 
species recognition (see Horner and Padian -- "The evolution of ‘bizarre 
structures’ in dinosaurs: biomechanics, sexual selection, social 
selection or species recognition?" in J. Zoo.) would benefit from such 
plasticity, especially in areas that enable visual differentiation, in 
the sense that a ready path to morphological diversification and 
subsequent speciation could further habitat exploitation. I propose the 
resulting 'clutch' of related species be called a 'genus' ... er, never 
mind.

I suggest (again) that imprinting is a mechanism in extant animals which 
both highlights the importance of species recognition as a tactic and 
levers aspiring young critters into a morphologically exaggerated future 
-- as in, "Wow, you look even more like Mama than Mama does."

If the above is correct, the implication is that at least transitory 
early parental presence is fundamental, perhaps even necessary, to the 
creation of "bizarre" and diverse-but-related taxa, at least within 
larger vertebrates. Sexual selection apparently does NOT need an 'early 
look' at conspecifics to function, but obviously could 'co-exist' w/ 
recognition w/in a species...