IE Trees: innovations unmarked

[Larry Trask]

On Thu, 2 Sep 1999 ECOLING at aol.com wrote:

> The other is that trees, as discussed by the proponents
> of orthodox theory in this thread, do NOT fully reflect
> notions about retentions vs. innovations.

> We cannot see from a single binary branch on a tree
> whether the RIGHT branch innovated (and all further
> descendants of that branch share such innovation(s)),

> or whether the LEFT branch innovated (and all further
> descendants of that branch share such innovation(s)),

> or whether EACH OF THE TWO branches had
> innovations common to all descendants from their own
> respective branch.

> Perhaps I have missed something, but the defenders
> of the orthodox theoretical view seem not to be taking
> the valid part of the commentors' messages with enough
> weight???

> Should we MARK points of innovation on trees,
> to indicate which branch innovates, or if both or
> more than two do?

We don't normally attempt to draw trees in such fine detail:
this would scarcely be possible.

As a rule, we draw trees that represent significant degrees of
divergence, meaning that each daughter of a mother exhibits a
significant number of innovations.

Larry Trask
COGS
University of Sussex
Brighton BN1 9QH
UK

larryt at cogs.susx.ac.uk