Point of brooding is...

[John Bois <jbois@umd5.umd.edu>]

On Fri, 5 Mar 1999, Ronald Orenstein wrote:

> We have NO evidence that these animals sheltered their young
> after hatching (living megapodes do not, so the behaviour is not even
> universal among living birds).

Without arguing against your position--this behavior may be (probably is)
derived. 

> The absence of equivalent brooding structures in non-birds today, which
> may have an equal investment in protecting their young, suggests that it
> might be difficult to argue that a need to brood drove feather
> evolution...

Who do you mean here?  I would argue that a prime benefit of brooding is
to keep egg temperature elevated, thus increasing the rate of embryonic
development allowing for greater organogenesis without spending eons at
the nest. So brooding-to-keep warm should primarily be associated
with endotherms.  Aren't birds the only warm-blooded egg layers around (I
know there is a snake which can shiver itself warm)?