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George Olshevsky (dinogeorge@aol.com) wrote:

<Who's talking about families? Narwhals >do< look significantly different
from other whales, and they >do< get their own genus.>

  Maybe I should have used species of *Mesoplodon*, which have color
variations without much morphological variation. Both extant monodontids
today, the narwhal and beluga, are morphological nearly identical,
including fluke structure, but have distinct behavioral and color
patterning, but also have overlapping northern ranges. Only narwhals and
other extinct monodontids, such as *Odobenocetops*, have the tusk, but the
latter is even further removed morphologically from the extant monodonts
that makes the beluga the really odd one when considered in their own
group. In *Mesoplodon* color variation is extreme along with tooth shape,
appearance, and size, and these are granted on the basis of genetics only
different species/subspecies based on sequence percentage variation.
Cetologists can differentiate southern and northern populations of orca on
the basis of color variation and fin shape, "at a glance", so does this
make them different from each other, or just regional variation? And while
we're at it, there are dog breeds that could be classed as different
species at a glance, such as the prognathous jaw of bulldogs or the huge
size difference between wee-but-feisty Chuhuahua's and giagantic St.
Bernards, the sleek pointers and afghans and the slung-low Daschund. If
at-a-glance differentiation was really viable, why are the dog breeds not
different species? Certainly none of these breeds can normally couple and
therefore breed, and most certainly not between the extremes of the
species, and this goes for the oft-joked Shi-tzu [not Shit-zu, despite how
the name can be pronounced, the t is on a different syllable] and bulldog
cross, which I will not name here (and people have tried to breed the two,
it doesn't work).

  At-a-glance is a testable theory, and applying it to the data (extant
forms) falsifies the theory. Whatever Thomas Jefferson could do atop his
horse is the layman's concept of superficiality. Taxa are not superficial,
and deciding a rank based on something superficial just shows how far it
is from Science. T. Jefferson's horse isn't very scientific, and having
stripes doesn't make the quagga a zebra, just a funny-looking equine,
despite Victorian at-a-glance systematics.


Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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