species and roles

[Kenelm Philip]

> The concept of constraints canalizing evolutionary possibilities is
> precisely the opposite of what these guys [Mayr, Stanley, Gould, etc.]
> were talking about.

A rapid scan of D'Arcy Thompson's _On Growth and Form_ will show one that
various constraints _do_ 'canalize evolutionary possibilities'. Living
organisms still obey the laws of physics. But I doubt that orthogenesis
refers merely to that kind of constraint, or everyone would accept it...

                                                        Ken Philip
fnkwp at uaf.edu