families as biotic units?

[Curtis Clark]

At 02:40 PM 2/28/99 -0800, Allan Shanfield wrote:
>Please forgive the simplistically broad scope of my question but I am
>interested in: Do families act as biological units? - especially in
>terms of competition both current and in the paleo record.

This is a trivial part of an important question: do clades act as
"biological"[ecological] units? Only in that context is it worth
addressing.

>Was/is there competition at the family level [...]

The "family level" is a purely human construct. No two families are
comparable, and many commonly recognized families are not even clades.

It seems to me that competition among clades would be through differential
rates of speciation and extinction, which I infer is somewhat different
from the question you are asking.

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