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


"Oh no! Not the palaeoclime/axis tilt argument!"

Now some of you out there will have a copy of Carroll's 'Vert. Palaeo.'. Here
in sunny so'ton, WE DON'T. So, if you have this volume to hand, could you please
do me a favour? On p.487 of said volume, there is supposed to be a joke. Please
mail it, as I'd like to know what it is. Many thanks.....


Cheetahs are cool! He he heh. O'Neil et al are probably right about the
Pleistocene bottleneck that these animals endured, but if so, how can the
variation amongst cheetahs be explained away? African (and probably what's left
of the Asian too) cheetahs are practically identical genetically, but there are
some odd ball populations; one in Egypt - these cheetahs have very very short
fur, and are a browny colour (one was photoed last year); the 'woolly' cheetahs
from ?the Aberdares (thick coats, a profusion of tiny spots); and the expanding-
range King cheetah, a morph that some workers think is a special forest-adapted
species-in-the-making. As regards the dino-link, cheetahs are especially
interesting because, despite their morphological disparity to other felids, they
are in fact very close, recently evolved relatives of the other cats, being
very close relatives of pumas (there are intermediate fossil species, and even
a living, enigmatic cheetah-like puma-type morph called the onza). There's a
lesson for phylogeny there, but of course one that, for purely fossil species,
is invisible. 

The grey whale (_Eschrichtius robustus_) is another good example, seemingly
being a very recently evolved, derived rorqual. Like the cheetah, its high
degree of morphological disparity relative to other (living and fossil) species
has traditionally led to the conclusion that it has had a long, independent
history. Now THAT'S  the lesson for phylogenetic inference of any clade's
members: divergence of morphology/characters from other clade members DOES NOT
equal divergence time. I'm sure dinosaurs underwent the same events....  So does
this all come down to the rate of evolution? Or could it be part of the case for
punctuated equilibrium?

I'm off for a 12-day field trip to Yorkshire now. Staying in a tent at the back
of a pub. Don't know how I'll cook, as we have no kind of stove or anything.
Guess I'll be living off crisps... well, hope my files don't fill up in my
absence. Be good people! I leave you with that all-time classic Ozzie series,

"We are going to RECREATE the forest. We photograph it, then we reconstruct it
in the lobby of the casino, out of plastic trees, like this one.."   "What about
all the animals?"  "plastic animals"  "PLASTIC ANIMALS, yes, we'll have plastic
animals for all the kiddies..."

"You have your moments, not many of them, but you do have them" - TESB