Date: Thu, 27 Mar 97 21:09 EST From: dave evans <T442119@RUTADMIN.RUTGERS.EDU> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1155$foo@default> Subject: Re: _Drosera filiformis_ complex
Hi Jan,
> > Seems to be an even greater difference between these two
> > Drosera than between the two subspecies of S.purpurea.
>
> But in _Sarracenia purpurea_ a rather clear geographic distinction
> exists.
Eh? Where is this split? We have S.purpurea up and down the
east coast and the two subspecies meet and interbreed (perhaps
not any longer though) in New Jersey. Though many, many of the
more northern bogs are now missing, as are the plants. Gone to
pasture, that's where they've gone. The larger D.fili. plants
are all clumped together within a certain range. Do we find any
of the smaller plants in there along with them? I have only
heard of one population of the smaller plants in Fl. Is tracyi
present there too? If so, do they interbreed? I know they have
the abilty to, if both were present, but that not the same thing.
> Although there is no real disjunction in the latter, we have
> a +/- homogeneous northern population and a (somewhat less
> homogeneous) southern population. An eastern/western separation seems
> to exist between the varieties (so far not subspp.!) of _Drosera
> filiformis_ with some overlap in Florida and Georgia. But the
> distinction seems to be ecological rather than geographic. Therefore,
> their staus does probably not need to be changed.
Ecology seems to me to be more important than geography.
After all, the way an organism relates to it's environment is
much more distinctive than not being able to gets it's pollen over
a mountian. Though, that can result in specification since one
group's ecology may becomes different from the other now geo-
graphically seperated population(s). Changes in ecology are
what force population to change (evolution) by selecting for
traits that better fit the new ecology.
On that note, has anyone done a comparision of the DNA from the
organelles which are not effected by meiosis in these two, so
far, varieties?
> But they are given the names they ought have.
That's because the flowers are nearly identical, right? Are there
differences in the flowers between the two subsp. of S.purp?
> Who *knows* that? Any evidence?
Yes, the traps on tracyi are shorter, the leaves are twice as
long and they have very little hope of living through freezing
(and no hope of flowering) temps while filiformis can. Also,
the bottom part of the stem can become nearly woody, this
doesn't happen in the smaller plants. I don't see the need to
worry over the flower morphology too much, since there isn't
much (like a pollinator) that could force the self-pollinating
flowers to become different.
The rest of the plant has changed while the flowers remained
about the same, since they have had no need to adapt to new or
changing pollinators.
> This is *your* chance! Propose the new combination and you will once
> overcome Goof Troop logic. But please check carefully if a new
> combination is *really* necessary (doubts noted above) before you
> publish anything.
Well, that's just it. Why change it if everyone already knows it? ;)
Seriously, I don't know enough yet to be 100% sure. Which do you
think is the older of the two? There are still some questions
unanswered like, 'Why are the traps on tracyi green?'. What
advantage was that? Would tracyi out compete the smaller plants
on it's home turf?
> > BTW, if there has been no published subspecies, why are they
> > not called _D. filiformis_ and _D. filiformis var. tracyi_?
>
> They *are* called like that. I do not understand this question.
Sorry, I read too much into "_D. filiformis subsp. filiformis var.
tracyi_" from your reply. The subsp. bit was just to illustrate
that the only subsp. is filiformis, I guess. It threw me since
I thought for there to be a _subsp. filiformis_ another, say
_subsp. wrongida_, has to be published and then the plants
represented by the type are then to be called by the same name
at both species and subsp. rank.
Sorry for typos, I don't have time to proof it.
Dave Evans
This archive was generated by hypermail 2b30 : Tue Jan 02 2001 - 17:31:00 PST