[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

LONG NECKS IN GEESE ETC



> Sorry, this doesn't convince me.  In fact almost all geese forage in
> extremely short grass areas - often stuff a sparrow could see over.
> 
> I am not saying that long necks weren't high-browsing adaptations.  But they
> may also have been useful in spotting distant predators.

The actual reasons for the evolution of long necks in which they don't seem damn
damn obvious must be exclusive to the animals considered. It is too generalistic
to argue that all long-necked extant birds evolved their necks for the same
reason. Ratites, and probably bustards too, accentuated the neck because it was
beneficial to their environment (tall-grass grasslands). 

However, early forms were geese-sized, and thus the argument that they needed
such a feature to see over grass _might_ be correct. Only later have ratites
become giants. BUT ratites seem to have originated as forest dwellers, this
might debunk predator-spotting as an explanation. Having become small,
flightless tinamou-like forms in the Eocene, ratites might have evolved long
necks for.. for (ahem) HIGH BROWSING. 

As for anseriformes, their fossil record also needs to be consulted. Basal
swans+geese might have began lengthening their necks to increase their reach
beneath the water. The grazing _Anser_ and _Chen_ geese are more recent
innovations, modified on this bauplan. Perhaps looking at Magpie geese and
screamers will answer this question.. err, why the long neck, that is..

In short (sigh), the evolution of long necks in these birds aren't analogous to
the sauropodomorph (HATE that stupid word!) necks.. did these dinosaurs start
as amphibious, swimming herbivores? Nooo... did these dinosaurs start as
miniature forest browsers?? Hmmm, then again (Olshevsky fuel?)...

Not that I want to get involved in any of this stuff of course..

"General, there's a fleet of star destroyers coming out of hyperspace in sector
4"  "Re-route all power to the energy shield. Gotta hold 'em off till all
transports are away. Prepare for ground assault."

DARREN NAISH