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Re: primers

Mesosuchus (Mesosuchus@aol.com) wrote:

<Although dogs is an extreme example, how can we then assign different
species to dinosaurs that show much smaller variations, that could be a
result of population isolation, for example. Has there been any
morphological studies comparing the variation found within a "natural"
extant species to the perceived variation seen in an extinct species.>

  Based as they are on fossils, only morphology can be used to compare
permineralized bone to those of modern forms, so in paleontology, an
essentialist, almost phenotypic approach has to be taken in species
comparisons, as has been done for some time, though the practice is
"regulated" by more scientific methods than those used by Linnaeus and
Cuvier. Relative species groupings will always be subjective to the
author(s) and study involved; no way around that, I think. hat some
morphology (muscles, tendon, integument, color) is modern forms used to
distinguish more species known than fossils available to compare
substantially, it is likely that whatever morphology we use may in fact
describe a "greater than species" grouping for fossils, OR it suggests a
"finer than species" group for living forms. If we define species
diversity on skeletal morphology, there will be a whole lotta lumpin'
going on; if, however, we define species on distinct, tiny features, a lot
of fossils will get "split" and elaborate taxonomies become prevalent. One
version will result in massive taxonomic "loss," the other taxonomic
"gain," a Bulls/Bears economy of nomenclature, but there will be taxonomic
_change_ no matter what.

  My opinion, anyway.


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.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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