Hi Matt,



I also have seen the term convergence applied to the ETB/GTP "phenotype" in many snake books. But this does not make it right. As I already mentioned, this phenotype arguably consists of several different traits, not all of which necessarily evolved in a convergent or parallel manner.



Furthermore, it was not that long ago that convergent evolution and parallel evolution were taught as synonyms. And not just in snakes books, but in general science texts as well.



Parallel and convergent evolution are examples of concepts and are open to subjective interpretation over time. Heck, in herp literature alone there have been dramatic shifts in the use of the following concepts in the last 20 years:



Venomous/non-venomous, species, viviparity, ovoviviparity, ovoparity, and probably many other concepts that I could think of once my AM coffee kicks in



Us lay people tend to think of many of these "terms" as being dichotomous... either a snake is venomous or it is not, either a snake is a "live-bearer" or an "egg-layer", or two snakes are the same species or they are not.



But none of these examples are dichotomous at a conceptual level. All occur on a continuum.



Convergent and parallel evolution are no different.



At any rate, just throwing this out there for general consumption, not necessarily directed at you in full.



>>On another note - as regards this particular thread, I believe I've seen the Emerald Tree Boa/Green Tree Python similarity described as *convergent* evolution in at least one if not more of my many snake books.
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1.1 Gonyosoma oxycephala - (Silver/Yellow)



3.4 Gonyosoma oxycephala - (Green)



2.1 Gonyosoma janseni - (Black)

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