I believe that the term "diversity" is being used rather differently by some of
us. In the broadest sense, every individual specimen that exists "preserves
diversity" with the only exception (for the most part) being those that are
derived from tissue culture, and only then in so far as they do not flower,
they do not produce seed and there are no TC based mutations. As far as
cultivating under similar conditions goes, the different permutations of
conditions of growers around the world probably comes close to the different
permutations of conditions found for some species of CP (take Darlingtonia, for
example).
Besides what counts when we speak of similar, just those aspects of the
environment that are immediately visible?
> There is no way to preserve significant diversity
> unless a large number of plants, preferably from different sites, are
> cultivated and one keeps careful track of each plant, where it came from,
> and who it's parents were.
Obviously, diversity is not based on whether or not someone is there to
record it. :) Nor does diversity necessarily follow from either
isolating specimens from each other or from maintaining some presumedly
similar specimens in close proximity. At least for me, I would not
define "preserving diversity" as it is relevant in most cases, as a
conjoint to preserving varietal characteristics. Hence, whether you
decide that one of those ugly ad-mixtures of seventeen parent nepenthes
hybrids increases or decreases "diversity" is entirely based on how you
define the term. For myself, whether ugly or not, they have in some
ways increased the potential diversity of the genetic material avialable
for the future (Even if we shudder to think about the implications!).
More importantly, diversity is not absolutely equivalent to
survivability, even though as a general rule we may presume that at any
one point, diversity is likely to (but will not inevitably) increase the
probability of survival.
Finally, the diversity represented by all the
> plants of a species grown by everyone around the world cultivating that
> species is probably insignificant relative to the plants growing in a
> different site.
I would have to disagree here as well, this statement depends on the number of
plants in the wild. As there are less than dozen known sites of S. oreophyla
in existence, it may be (but of course it is not certain) that greater genetic
diversity exists among those plants around the world in cultivation. For
larger populations, it is a fairly safe bet that greater diversity exists in
the wild because greater number of plants exist in the wild.
>Unfortunately, I absolutely do not buy the idea that we
> are generating or selecting for genetic diversity in cultivation. In
> fact, we are doing the opposite as I believe Michael pointed out.
> Wayne Forrester
Well, IMHO, I must at least partly disagree. We are not necessarily
"generating diversity" nor are we doing the opposite. The phrase "selecting
for genetic diversity" (if we exclude tissue culture plants) is almost an
oxymoron.
It almost seems that plants in cultivation are somehow defined as diversity
challenged. This does not make sense from a scientific standpoint, any more
than saying that an isolated site in the wild is diversity challenged. Even if
both may have come about from one (or a few) parents many generations back.
Plants in cultivation are not necessarily preserving diversity nor destroying
it. If a plant that otherwise would have disappeared, survives, the potential
diversity of the species is increased. This may still be irrelevant to the
survival of the species. The same statement holds whether the plant is in
someone's collection, in a botanical garden, or in situ in the wild.
As always just IMHO,
Tom in Fl.