Re: seeking clarification on the cladism debate

[Dinogeorge@aol.com]

In a message dated 10/17/01 6:02:43 PM Pacific Daylight Time, 
tmk@dinosauricon.com writes:

<< No, not necessarily. It may have had a very short independent lineage, but
 it would still have all the same ranks as a very long one.>>

I neglected to mention that I was referring to morphological distance rather 
than temporal distance. We can't tell anything about temporal distance from 
only one species, but we can certainly see that the species is very distinct 
morphologically from its nearest relatives.
 
<< And in practice, it's often difficult to tell whether something has a long
 or short independent lineage. Does _Archaeopteryx_' lineage, separate from
 other avians, stretch back to the Triassic (as Chatterjee would have it)
 or merely to the early Late Jurassic? >>

That doesn't matter. Archaeopteryx is wildly different from other birds 
(except its close relatives Jurapteryx and Wellnhoferia, of course) and, if 
you are into typological classifications, would require considerable 
taxonomic separation. If you're into cladistic classifications, however, this 
whole dialogue should be pretty much meaningless to you.