Re: MY THOUGHTS ON THE 'DINO/BIRDS'

[Jonathon Woolf <jwoolf@erinet.com>]

Allan Edels wrote:

>     Without any real evidence, what follows must of course be seen as pure
> conjecture:
>
>     Imagine a climatic change in some areas, where the temperature ranges
> and moisture contents didn't change much from previous decades, but the
> frontal systems changed their frequency.  By this I mean the cold-front to
> warm-front (and vice versa) changes occurred more rapidly than before.  This
> would create a situation where the climate was essentially the same, but
> winds would have been more rapid, perhaps more constant (sort of like
> Aruba).  Imagine that some small theropods had already evolved these strange
> structures (feathers) for display, which included jumping up and away from
> rival males, as well as making themselves look larger at will.  Imagine one
> or more of these dinos getting caught in a sudden well-placed gust of wind,
> and the resultant display and struggle for control (in the flight) producing
> a new standard of excellence for the other dinos (of the same species) to
> emulate to try to impress their prospective mates.  (I am suggesting that
> some of the dinos that end up in the air may not necessarily land real
> well - or even survive - and that others, with strong enough muscles in the
> right places would have a better chance at a safe landing).  Also, a better
> way to avoid larger predators.
>
>     This little scenario makes somewhat more sense than the chasing insects
> with arms/wings outstretched leading to flight; or the arboreal dinos
> gliding, then learning powered flight (or as Dinogeorge calls it:
> "ornithoptering" ).  I am not precluding the possibility that some arboreal
> forms may have had the distinctive jumping and short-hopping that some birds
> exhibit today in courtship or in tentative feeding situations, and that may
> have helped them develop powered flight from the trees.
>
>     My little scenario adds climatic pressure as a driver for evolutionary
> change, something rarely mentioned in discussing dino to bird evolution.
> (Yes, I know George, "Birds Came First" :-).
>
>     As I said, this is truly speculation.  Any comments??
>

I kinda like it, Allan.  It's interesting, it's plausible (IMO), it's creative,
and it shows a better understanding of the evolutionary process than a lot of
the ideas that are being kicked around.  I'm puzzled by this tendency to assume
that however feathers evolved, they must have had a _practical_ use: insulation,
brooding, whatever.  Modern birds have evolved some of the screwiest things as
sexual displays: the peacock's tail, the gooney bird's dance,  the kakapo's
booming ritual, etc.  I look at _Caudipteryx's_ tail-fan of feathers, and I see
a display adaptation pure and simple.

It occurs to me that you might not even need the 'strong windstorms' bit --
maybe, flight got started just as a way for courting males to jump faster and
higher than their rivals.

-- JSW