Fw: Rejected posting to ARISAEMA-L at NIC.SURFNET.NL part 2

[Wilbert Hetterscheid]

Continued from part 1:

> 2) Now I am going to address a more fundamental point and that is the
> parallell between evolutionary processes as going on in nature v.s. human
> exploitation/copying of those processes. I have ended the above paragraph
> with that distinction. Mark Burack asks if "undetermined" species may turn
> out to be natural hybrids. Sure enough, when found in nature!!! Many
> entities we cal "natural species" may have evolved through a chain of
> processes of which hybridisation is one. Not to say, of course, that a
> natural hybridisation always leads to a new species. In order for
successful
> hybridisation to occur "naturally" any or a combination of circumstances
> must apply (proximity of different species geographically, coinciding
> flowering times, compatibility of genome-parts dealing with developmental
> success of embryos after pollination, correct pollination-vectors, correct
> circumstances for hybrids to establish from seed etc.). For a species to
> develop from this, the factor of duration/perpetuation is essential too.
We
> would not easily recognise a swarm of hybrids as a species when they
appear
> to be a mere ephemeral, very localised phenomenon. In fact, recognising
that
> a species is of hybrid origin is quite often done after the initial
> publication/recognition of it at the species level.
> In older days (when biosystematics reigned superior) we did it the other
way
> around, and recognised enormous numbers of species merely based on the
idea
> that hybridisation had occurred and that observed chromosome patterns,
> indicating this, were tantamount to establishing species. These
> "microspecies" e.g.
> were recognised by the hundreds in a temperate Asteraceae genus as
> Taraxacum. Luckily most of us have seen the "errors of our ways" and have
> not perpetuated this line of recognising species this way, thereby
accepting
> that hybridisation as a means of speciation is o.k. but NOT the final
story.
> Eduardo says correctly that plants don't always tell us, and I say that
that
> doesn't matter at all. We recognise species even when we know nothing
about
> their origin.
>
> How different are things with cultivated plants, of which we DO actually
> know their origin (for the sake of argument I exclude ancient cultivars,
> landraces etc., of which the history has not come down to us in written
form
> but of which we DO know they are "man-made"). Bjoern asks why we "improve"
> plants at all when nature seems to be perfect to him. Well, Neill answered
> that question perfectly correct. Whether nature is or is not perfect is an
> evaluation of humans themselves and obviously we have decided that it is
> not and there is a whole lot to improve. In fact we exploit nature to our
> own goals but find that we also need to manipulate the natural products in
> order to make them more to our liking. So we may start from accepting that
> man-made
> products, derived from "natural" products exist. And here lies a watershed
> distinction between two worlds, the "natural" world where evolutionary
> processes run in a number of ways and result in end-products
> (species/populations/individuals) that make up the pattern we call
> "biodiversity". Opposed to that is a grand
> diversity of products brought about by man-made interference, whish does
NOT
> at all duplicate biodiversity as we percieve it in natural surroundings.
Not
> one Asteraceae taxonomist dealing with the genus Gerbera and revising it
> taxonomically will describe for that genus all the morphological
characters
> he may have seen on Gerberas in a vase!! Nor will a Lactuca taxonomist
> define that genus using the thousands of cultivars of lettuce as a basis
for
> describing the morphological diversity in that genus. In fact NO
taxonomist
> working on the revision of a genus of plants will include cultivars and
> their characters in his work. He is working in an evolutionary context and
> has a goal to publish with that paradigm in his mind. Apparently that does
> not include man-made plant products (e.g. cultivars).
>
> Obviously we DO perceive a difference between products of evolution as
found
> it in nature and manipulated man-made products
> derived from the first group. In fact, we strive to differentiate them in
> nomenclatural ways too. The first group (taxa, like genera, species,
> families) are named using Linnean conventions described in the Botanical
> Code, but to recognise the other set of end-results we use a different
code
> (ICNCP) that even tells us that we deal with a distinct entity, the
> cultivar, which is NOT found in the Botancal Code. And although we may
> indeed use processes or parts of processes as found in nature
(hybridisation
> as a prime one), we still feel that these processes yield different final
> entities under cultivation (man-made) circumstances. We do not create
> species in greenhouses, even though we may use "natural" processes!
> Obviously we feel that what happens in nature and in greenhouses, although
> superficially similar, IS essentially different.
>
> I have written several papers with colleagues on this point because as
> strange as this may seem, in history this obvious fact has seldom been
given
> recognition. In fact, this problem arises from the idea that man is part
of
> nature, hence what he does is, and what he creates is (Neil's point too in
> his last message). Unfortunately, those saying this forget that man has a
> unique feature, not found anywhere else in nature, and that is that he
acts
> with a pre-set goal. Although he may use hybridisation as a process to
> create new things, he does that with purpose. If I wanted to create a red
> Gerbera,
> I could think of finding the fastest of most sucessful way of doing that
and
> start by crossing plant A with B because I think that particular
combination
> would be the best one for succes. Would an insect visiting Gerbera plants
in
> nature work that way? Would nature (or a player in nature, or a process)
> think of putting plant A and B in proximity to create a red-flowering
> offspring?
> It is not inconceivable that at some short moment in time, nature would
> accidentally create that red gerbera but then a plethora of circumstances
> must be met for it to establish, whereas we, humans, would start
> deliberately protecting that rare offspring, thereby increasing
> exponentailly its chance to survive. Rightly so, because we WANT it to
> survive! Could we say the same thing about nature? Would nature have its
> "mind" set on preserving that red form? Guess not.
>
> My conclusion: although we humans may be part of the natural context, we
may
> consider that some of our actions could be classified in different
contexts,
> even if we would like nature to be the all-embracing context in which we
do
> what we do. For purposes of human interest we already have created a
> plethora of contexts in which we deal with objects and which we classify
and
> name especially for the purpose of that context. In our case, we have the
> horticultural context, in which we try to establish methods, names,
products
> servant to the goal of the context: improving our surroundings/lives (see
> earlier). I think that such a context needs its own labels and entities in
> order to keep it from being confused with items in other contexts.
Therefore
> I think we must not look upon man-manipulated plants as the same things as
> we find in the wild and logically therefore  NOT use the same
classification
> philosophy and nomenclature. Species names therefore are insufficient.
> Species names are originally "devised" to indicate natural entities.
> Linnaeus even excluded man-made plants from the species level (he made
them
> in "varieties" he often merely indicated by letters (alpha, beta)). Of
> course, he sometimes did not recognise that a number of plants was not
> God-made (his interpretation of the leading force of nature, not mine) and
> gave them erroneously species binomials (e.g. Zea mays, Solanum tuberosum)
> but we all know that was a mistake. These names perpetuate because we are
> used to them
> but no evolutionary scenario of the genus Solanum or Zea (should) includes
> these.
>
> In conclusion I am not saying that humans are "separate" from nature but
we
> must also accept that our actions have added a new kind of subclass of
> contexts, in which pre-mindset things happen, something that nature had
not
> been confronted with until Homo sapiens came into being. Interesting is
that
> no
> evolutionary scenario up to today, includes the existence of houses, cars,
> railroads, cultivars, domesticated animals, even though each and everyone
of
> them has been "created" with the aid of "natural processes". They are all
> separated from such scenarios because they are "man-made", and that is a
> clean observation!!
>
> 3) Bernhard Strolka: at this moment a PhD student in Leiden (Netherlands)
is
> studying the genus Amorphophallus at the molecular level. He is putting
> Amorphophalli, -uses, -us in the blender by the dozens....
>
> Cheers,
> Wilbert
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