Susan Erickson wrote:



Ok - I agree with the theory Rob is talking about. But I also
know that we are not the experts on what is or is not lost in
this type of breeding.

Not long ago it was reported that a pair that both displayed the
recessive (desired) characteristic were breed and the resulting
population had 1/4 or 1/3 that reverted to the 'absent' dominant
character. This character had been "breed out" of the parents
and should not have been available to surface. Mother Nature
still has the top hand in all of this.

I assume you are talking about the recent hubbub about plant genetics
that was released a few weeks ago. This gets more and more blown out of
proportion every time I hear it...

So, if I read the initial reports correctly (I'm working from a copy of
the paper), this experiment was done in Arabidopsis thaliana (a common
lab plant). The crosses were actually selfings of plants homozygous at
a given mutant recessive allele (Called 'HOTHEAD', no, i don't know
why). The mutant allele designated hth, the 'wild type' allele HTH.
So, these plants were hth/hth. The scientists noticed that a
non-trivial percentage of the offspring were hth/HTH (heterozygous).
This is, of course, not possible. *grin* However, the percentages
weren't 25-33% reversion. The authors report 10% (the number is getting
exaggerated over time).

Mendelian genetics dictates that we can only inherit the alleles that
our parents have. So, this is a really big deal. It should be
impossible for hth/hth to give rise to hth/HTH progeny. There are a
number of possible explanations given, the practical upshot of which is
there is a lot of work to be done. One of the best theories right now
is that there are long lived RNA molecules in the cell (remember,
DNA-RNA-protein) that serve as a template to 'correct' mutations at
this HOTHEAD locus. That would be interesting... But, before we throw
Gregor Mendel out the window with his peas, we need to confirm this
result for other gene loci. So far, it has only been observed at this
one. And only in arabidopsis (not in other plants, not in animals, not
anywhere else...). It can't be that common an occurance, or somebody
would have noticed it before.

Anyway, I think it is a far leap from this paper to suggest that there
is some sort of mystical force of mother nature that keeps genetic
diversity silenced in some fashion, ready for expression whenever the
plant needs it. Some small percentage of genes might have this 'backup'
capacity, but even with the best explainations we have for the hothead
phenomenon so far, this backup capacity would be corrupted or lost over
more than a few generations. I think for most purposes, mendelian
genetics will still hold. Just like for most purposes Newtonian physics
works (but we need quantum mechanics for really small stuff).

Genetics is still a complicated and mysterious thing, anybody who
claims to have it figured out hasn't been paying enough attention.


When we breed to intensify color or any other characteristic we
are in effect hybridizing to create a more beautiful species.
Yes, I would do it if I could. It is the nature of the beast
(man) to selective breed what he wants to see in his plants. As
long as we say species x species is still species we are going to
'beautify' the species. Heck, I would love a C. aurantiaca that
did not self before I could enjoy the color and line. I am all
for species that carry the desirable characteristics.
SuE
http://orchids.legolas.org/gallery/albums.php

That was exactly my point, said far more adeptly than I could. We are
hybridizing when we breed species.

--
Rob's Rules: http://littlefrogfarm.com
1) There is always room for one more orchid
2) There is always room for two more orchids
2a) See rule 1
3) When one has insufficient credit to obtain more
orchids, obtain more credit

On Tue, 05 Apr 2005 11:49:46 -0400, Rob Halgren
wrote:


So, if I read the initial reports correctly (I'm working from a copy of
the paper), this experiment was done in Arabidopsis thaliana (a common
The authors report 10% (the number is getting
exaggerated over time).


Thanks for the correction and the lesson. Glad to hear it is
only one experiment and the old rules are still the rules of the
road. It was a bit of a scary thought that such things could
"come back".

SuE
http://orchids.legolas.org/gallery/albums.php

Susan Erickson wrote:
On Tue, 05 Apr 2005 11:49:46 -0400, Rob Halgren
wrote:



So, if I read the initial reports correctly (I'm working from a copy of
the paper), this experiment was done in Arabidopsis thaliana (a common
The authors report 10% (the number is getting
exaggerated over time).



Thanks for the correction and the lesson. Glad to hear it is
only one experiment and the old rules are still the rules of the
road. It was a bit of a scary thought that such things could
"come back".

SuE
http://orchids.legolas.org/gallery/albums.php

An interesting experiment, though. And well documented. But, as
always, extraordinary claims require extraordinary proof. I think the
old rules of the road are still mainly in force, there may be some local
ordinances that get in the way in some places... Call them speed traps.
*grin*


--
Rob's Rules: http://littlefrogfarm.com
1) There is always room for one more orchid
2) There is always room for two more orchids
2a) See rule 1
3) When one has insufficient credit to obtain more
orchids, obtain more credit

On Wed, 06 Apr 2005 12:36:30 -0400, Rob Halgren
wrote:

An interesting experiment, though. And well documented. But, as
always, extraordinary claims require extraordinary proof. I think the
old rules of the road are still mainly in force, there may be some local
ordinances that get in the way in some places... Call them speed traps.
*grin*

Speaking of speed traps...
Are you going to make it to Minneapolis?
SuE
http://orchids.legolas.org/gallery/albums.php

Susan Erickson wrote:
On Wed, 06 Apr 2005 12:36:30 -0400, Rob Halgren
wrote:


An interesting experiment, though. And well documented. But, as
always, extraordinary claims require extraordinary proof. I think the
old rules of the road are still mainly in force, there may be some local
ordinances that get in the way in some places... Call them speed traps.
*grin*


Speaking of speed traps...
Are you going to make it to Minneapolis?
SuE
http://orchids.legolas.org/gallery/albums.php

Yes, I'm planning on it, although I never did get my registration in.
*grin* Although since I've never seen airfares as usurious as those
charged to get to Minneapolis, I'm going to drive. My own form of
protest. It must be a one airline city... So I may find a few literal
speed traps.


If anybody between me (in Lansing, MI) and Minneapolis is looking for a
ride to the AOS meeting, I could probably pick up some hitchhikers.

Rob

--
Rob's Rules: http://littlefrogfarm.com
1) There is always room for one more orchid
2) There is always room for two more orchids
2a) See rule 1
3) When one has insufficient credit to obtain more
orchids, obtain more credit

Rob and Sue,

Wisconsin is where you don't speed from what I understand.

I'm usually about 10 over on the freeways and the cars are flying by in the
Twin Cities.

Looking at http://www.speedtrap.org/speedtraps/...y.asp?state=MN
Colorado looks more dangerous.

Hope you meet you both. Enjoy your stay.

Bob



"Rob Halgren" wrote in message
...
Susan Erickson wrote:
On Wed, 06 Apr 2005 12:36:30 -0400, Rob Halgren
wrote:


An interesting experiment, though. And well documented. But, as always,
extraordinary claims require extraordinary proof. I think the old rules
of the road are still mainly in force, there may be some local ordinances
that get in the way in some places... Call them speed traps. *grin*


Speaking of speed traps...
Are you going to make it to Minneapolis?
SuE
http://orchids.legolas.org/gallery/albums.php

Yes, I'm planning on it, although I never did get my registration in.
*grin* Although since I've never seen airfares as usurious as those
charged to get to Minneapolis, I'm going to drive. My own form of
protest. It must be a one airline city... So I may find a few literal
speed traps.


If anybody between me (in Lansing, MI) and Minneapolis is looking for a
ride to the AOS meeting, I could probably pick up some hitchhikers.

Rob

--
Rob's Rules: http://littlefrogfarm.com
1) There is always room for one more orchid
2) There is always room for two more orchids
2a) See rule 1
3) When one has insufficient credit to obtain more
orchids, obtain more credit

On Thu, 7 Apr 2005 18:18:59 -0500, "Bob Walsh"
wrote:

Rob and Sue,

Wisconsin is where you don't speed from what I understand.

I'm usually about 10 over on the freeways and the cars are flying by in the
Twin Cities.

Looking at http://www.speedtrap.org/speedtraps/...y.asp?state=MN
Colorado looks more dangerous.

Hope you meet you both. Enjoy your stay.

Bob

I grew up in Wisconsin (Madison) so I will agree. Hold that
speed limit to 5 over on I90.

We are flying. I have great faith in MN weather in April. Ours
is bad enough - they are predicting snow in Denver for Sunday.
We still have 65 at 8pm tonight. Spring in Colorado. The only
thing that changes temperature faster is Summer in Colorado.

SuE
http://orchids.legolas.org/gallery/albums.php