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On Thu, 29 Aug 1996, Jerry D. Harris wrote:
>         BTW, this message also serves as a test message; has this list been
> dead of late, or is it just me???

        Sure seems that way. I actually have a couple questions I've been 
wondering about... one of them is that I recently saw a structure in 
nature that is the only thing I can think of that paralells the evolution 
of feathers. It serves an aerodynamic, rather than insulatory, purpose, 
and someone has told me that these little tufts of down are from the 
thistle plant. The actual structure of each "plume" is a central shaft 
with secondary hairs branching off, it vaguely resembles the ratite 
feathers. The thistle down implies to me that even a 
relatively simple, ratite-like feather might have some serious aerodynamic 
advantages over simple hairs. On the subject of feathers, I'm surprised 
no one ventured to speculate where the one in the AMNH's natural history 
exhibit (a ratite-like plume in Cretaceous amber) might have come from, 
if not from a bird.
        I've also heard something to the effect that conifers would have 
been severely vulnerable to being fed upon by dinosaurs, because they 
only put out needles once a year, but yesterday I noticed that on a 
Metasequoia there was what appeared to be new growth coming out. So is 
putting out growth only once a year a specialization of modern conifers 
(perhaps it has something to do with their generally high-latitude 
distribution?) or the primitive condition which Metasequoia appears to 
have evolved away from?
        And these duckbills and ceratopians simply beg the question, yet 
again, why did dinosaurs get so large? Obviously, the environment has to 
select for it. But does the environment no longer select for these kinds 
of giants, or is there simply nothing today living that can respond to 
such selectional pressures the way dinosaurs did?