RE: Re: HYB: growth problems

Steve Szabo wrote:
>What was observed was natural selection in progress.
>When you find the reference and read it once more, it
>should note that the surviving radish plants probably
>had a higher amount of defensive bristles, hairs,
>what ever than the untouched group. What would be 
>interesting here, would be if the next generation 
>had a higher count of defensive bristles, hairs, 
>whatever, than the original remnants of the parent
>group. I would tend to think that some would, and 
>another generation of survivor off spring would more 
>clearly show the increase.

Steve, I looked through my stuff and found the
reference and it's definitely something different from
natural selection. I had come across it, when I was
"Googling" epigenetic inheritence. I have it saved as
a PDF (Adobe) File and will try to attach it to this
e-mail; if that doesn't work I can e-mail it directly
to anyone interested. The jist of it is, that there
was no selection going on. The caterpillar grazing
induced defensive changes in the plant itself --
higher concentrations of defensive chemicals and
hairs. But more interestingly, the seeds that these
"turned on" plants produced, grew seedlings with those
same defenses still turned on.

>If generations of caterpillars were also followed 
>there may be noted an adaptation of the caterpillars 
>to the increased defenses of the radishes.

That's a very interesting consideration. Presumably,
the caterpillars should be able to do something
similar.

And while I was looking through my saved references, I
saw something that might be of interest to anyone who
is interested in this sort of stuff. In certain maize
strains, it was shown that defoliation of the parent
during kernel formation, conditions those seeds to
germinate more vigorously and tolerate cold
temperatures better.
Although some possibilities were mentioned, I don't
think a mechanism has been determined for this
phenomenon. And I don't think they've checked the next
generation to see if it carries on or not. 
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