Date: Thu, 25 Sep 1997 16:15:57 +1000 From: Andrew Bernuetz <andrewb@camden.usyd.edu.au> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3703$foo@default> Subject: Further discussion with Rand
Rand,
I do agree with you on many of your points, I guess the easiest way for me
to reply to the various points is to list them as follows: (WARNING: THIS
IS A REASONABLY LONG TRANSCRIPT!!)
In regard to orchids being given awards for 'grotesqueries', I totally
agree. I figure you dislike the manipulation of nature by man (in an
extreme sense)- to put it briefly.
In regard to the production of 'uniformity' in dog breeds, I think it is a
matter of perspective. For instance, if you have a dog with a good trait(s)
it is often beneficial to cross this dog with another with the same
trait(s) to try and perpetuate this trait. If not the trait may be lost.
However, (here is where I agree with you) this inbreeding MUST be minimal,
and outbreeding incorporated every now and then to prevent recessive traits
coming to the surface.
You said: 'Other examples of ornamental breeding gone wrong by "scientific
method" abound.
.... The domestic animal trade is rife with them. Any hybridised plant
that cannot sustain itself at a natural, or on a commercial, level without
artificial, environment damaging support will do. Lawns.'
My lawn seems to grow quite well, I have never fertilized it, never sprayed
it, and if I don't mow it it grows into my Sarracenia pots. If anything my
lawn is a weed, and yes, it was man made. I think that if you wish to grow
anything (hybridised or not) it depends on the environment in which you
wish to grow it, in regard to it surviving.
I wrote: Did you know that commercial wheat and oat cultivars are both so
inbred as to be almost totally homozygous? This is why they grow true from
seed, as with many other inbreeding plants. (I should have also added many
other wild, natural species, eg, any self seeding drosera).
You replied:
And stand to be felled by any single disease organism and/or critter which
happens to adapt to find them tasty. The current wisdom on the so-called
"flesh eating bacteria is that it would not exist, but that we bred it
because we didn't know what we were doing with antibiotics. All very clear
... in hindsight.
You are absolutely correct, this is what I try and tell my colleagues here
about breeding for rust resistance in cereals. To overcome a single gene is
easy for the zillion or so rust spores which (via mutation and
hybridisation) become resistant. So they try and 'pryamid' genes, using a
number of different resistance genes to prevent rust infection, but
eventually this will be overcome too. It is a trade off really, you want a
crop that is uniform for harvesting, heading, nutrition, etc. But by having
this uniformity you open yourself up to problems such as you have listed.
There are basically two types of (natural) breeding systems in plants,
inbreeders (such as wheat and oats), and outbreeders such as rye and maize.
There are many levels in between. Both systems have their advantages:
outbreeders can exploit heterozygosity by quickly adapting to changing
environmental situations; inbreeders specialise in set environments. So,
usually, in a non-changing environment the inbreeders will be better off,
producing much seed via self pollination, whereas the outbreeders, not
being as uniform and having to be cross pollinated (relying on vectors)will
not be as prosperous. Only when the environment changes will the outbreeder
be better off, and the inbreeder some what decimated.
Rand also wrote:
When man attemps to construct a single resource habitat, it invariably
fails to maintain itself without self-defeating artificial interference
which has direct and devestating
effects upon the surrounding environs.
Exactly, but what else can you do? in regard to agriculture, which is easy
to relate to, the problem is that it is economically driven, and to do
agriculture in any environment you have to have interference by man. We
gotta eat.
Rand wrote:
>>Why not look for and to the marvellous plants that are already out there
>>(in this CP context), try to understand and preserve them, and leave nature
>>to make the variants, or mutants, for us to find? By most reports, there
>>are enough of them out there. Surely we are not so bored?
I replied:
>The problem with finding mutants, or leaving nature to produce them, is
>that it takes a long time, and in nature only mutants which are
>advantageous in the environment in which they are growing will usually
>survive and prosper.
Rand then repiled:
My point exactly.
Nature is not a uniform environment. A mutant for waterlogging resistance
will only be realised in a waterlogged paddock, not in a desert. So, a lot
of mutants have probably not survived. It is all envirnomentally dependent.
In a CP context, where the visual or ornamental aspects of a plant seem to
be most important, I think that mutants which may be easier to grow would
be beneficial. Not these stupid looking deformed plants we often see. All I
can say is, if people wouldn't buy them there would be no incentive for
people to PBR them, and try not to think of mutation as always being
deleterious.
Kind regards,
Andrew Bernuetz
andrewb@camden.usyd.edu.au
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