[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: New MANIAC book is out!
> I am becoming increasingly frustrated by the consistent use
> (in multiple camps, not just aiming at the MANIACs) of the
> terms "poor flier" and "good flier". What, exactly, is
> a poor flyer?
In the Kimmeridgian, even in the Early K, almost any dino that could flutter
aroung the least bit would have qualified as a "good flyer".
One might rather say "sophisticated" flyers, but even that is not too good. It
is really a continuum, with few birds flying more than marginally better (still
visible to natural selection, usually) than they need all things considered,
and there is a seamless (especially if viewed for more than 2 Ma or so)
progression towards secondary flightlessness. A few birds have indeed taken
flight to entirely new levels of apomorphy, but this has happened many times
and it is not at all obvious where to draw the boundary to less advanced forms.
What *may* be possible at least eventually is to draw the boundary in an
evolutionary sense: "good fliers" make their presence felt by inhibiting
essentially any and all "bad fliers" to evolve into "good fliers". That would
have happened some time after 130 Ma but probably before 100 Ma on most major
"Better fliers" and "worse fliers", these two categories do exist. But of
course, to each flying taxon *both* apply. And for most flying taxa, a large
proportion of comparison taxa would still be "approximately equally good
Do You Yahoo!?
Sie sind Spam leid? Yahoo! Mail verfügt über einen herausragenden Schutz gegen