orthogenesis, anagenesis, canalization

[John Grehan]

ken Kinman wrote:

>     In the meantime, at the risk of looking foolish, I am wondering how the
>terms anagenesis and cladogenesis might fit into this discussion.

As far as I am aware, neither of these terms has any direct connection to
orthogenesis. There is an overlap of issues concerning the restriction of
orthogenesis to linear (non-branching) evolution which would have precluded
cladogenesis. This restricted definition is, however, neither an accurate
representation of the concept of orthogenesis (at least based on my
examination of the issue) or is it necessary.

 And also
>a concept often used in developmental biology, "canalization", which I
>assume often tends to suppress cladogenesis in favor of anagenesis.

I admit my lack of expert knowledge regarding the current use of
canalizaation in
developmental biology so I canno comment. Perhaps someone else on the list can.

John Grehan