Question about Naked Ladies
J.E. Shields (Fri, 21 Dec 2007 11:41:40 PST)

Steve, Jim McK., Jane, and all,

I also encountered the term Rassenkreis first in regard to Lepidoptera, but
specifically to the butterfly Junonia coenia, which also ranges from
Florida across the central USA to Mexico and Central America. It its case,
I think there is at best very limited fertility between the Florida and the
Central American forms, but with the same continuous fertility between
neighboring populations. Steve described the situation very well
indeed. I'm pretty fluent in German, but I also had to check the spelling
before proceeding with my original posting.

I thank Jim McK. for reassuring me that cline is also applicable. "Cline"
might be more botanical, or it might be just a matter of years. I
encountered "Rassenkreis" at least 40 years ago. It could easily have
fallen by the wayside in that length of time, especially considering the
degree of Anglicization of science in the intervening years.

Jane, I have not encountered "continuum" used in a biological sense
before. This probably shows how narrow my biology reading has been over
the years.

Whether Jim's Lilium greyii/canadense situation is a cline or a localized
intergradation between two young, mostly allopatric and closely related
species is perhaps debatable. I certainly don't know the situation with
Lilium.

Where you have two mutually interfertile species existing in sympatric
populations, if there is a barrier, they can be pretty stable. Introducing
the human element may be all that is needed to overcome such a barrier to
interbreeding. I can see where, over time, and intermediate population
could take over or it could be extinguished. If the parent species include
individuals that are not fertile with members of the other species, they
might prosper as the hybrids decrease.

Getting back to vernacular names, I'd say there are many things you simply
cannot discuss using vernacular names. On the other hand, the day is not
far off when species, local populations, and individuals will be identified
and defined by their DNA. It's just the direction things are going and
will continue to go, barring some Armageddon or other broad catastrophe.

Best wishes,
Jim Shields
in central Indiana (USA)

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