Eastern/Canadian Tiger Swallowtails

[evoluhol at magnum.wpe.com]

"canadensis" specific


For many years we admitted that butterflies had clines, as a species range
was studied from environement to environment (usually altitude or
latitude), where environment effected forms both temperature and
genetically.  Species from one end of cline lost viability in breeding
with indivisuals from the other end of the cline but would breed with ones
next door all down the cline.

I have studied (not under electron microscope -- but neither does the
butterfly) tigers from Atlantic to Pacific and Canada to the Carolinas,
and they will vary from environment to environment (where there are
pipevine swallowtails there will be black tiger females).

Originally, the determination of "species" was left to the butterfly -- if
it bred and had viable male and female offspring -- it was a species.  If
there was no offspring or only males, it was not a species.

One "claim" of different species is that foodplants are different.  If a
tiger oviposits on aspen here at my house, and wild cherry in the valley,
it does not make it a separate species.  Viceroys here oviposit on aspen,
in the valley on willow -- those are not two seperate species.  If
cecropia oviposit on wild cherries on my mountain, and on maple in Green
County (NY) -- it does not make them separate species.

However, in my reading of the papers that claim different species, the
main argument seems to be the chromosome and gene differences under a
microscope.  "Canadensis" is clamed to be different from "glaucus" because
of the number of genes that are different -- which is backed up by
comparison with other species.

Ultimately -- what is happening here is a researchers attempt to overturn
the concept of species and propose a BRAND NEW CONCEPT OF SPECIES based on
the microscope quite apart from the butterfly's behavior.  There seems to
be in this concept that there is a point where after counting a number of
gene differences, just one more different gene constitutes a different
species. (??)

Meanwhile, my tigers are exempt from the controversy, they carry on their
life in spite of a labratory paper that says they shouldn't.  My tigers I
get 50 miles away that have distinct yellow spots on the under front
wings, mate with those I have here at 1,200 feet higher which have a
yellow "band".  The caterpillars variably will eat populus, prunus, or
crategus.

Dave