Cyperales or Juncales?
tdib at OCEANCONSERVANCY.ORG
Wed Jul 10 16:54:16 CDT 2002
Jim Croft wrote:
> - in many
> organisms (plants especially) the chances are fairly likely that progeny
> will end up growing in the same place as their parents who were most likely
> to be growing in the same place as their parents..., Even though it may
> be controlled by dispersal mechanics and the inverse square law rather than
> genetics, the net result looks and smells very much like inheritance and
> descent ...-These are observable facts and it is
> difficult to see why they should be ruled out as evidence.
Clearly there are cases where a distribution will appear intuitively logical given a
phylogenetic pattern, and that may indeed be the way in which it all worked out. But
there are also many cases where that is not so. The strategy must be to construct
the best relationship scheme possible, and then look at the distributions in that light,
to see what the biogeographic history might have been.
Just because distributions are observable facts, and may correlate with phylogeny,
does not argue that they are relevant evidence of relationship. There are two major
factors that can alter the nature of the spatial character, even if you view it as an
inherited character in some sense. The organisms can move in any number of
directions, and can move back - and the ground (or water) itself can move under
them and alter the relationships of the areas. As a result, "place" is simply not a
manifestation of a lineage-dependant process, and thus does not qualify as evidence
for discerning the contours of the lineage.
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