[Coral-List] Age of clones?
TDWYATT at aol.com
TDWYATT at aol.com
Fri Jan 20 16:42:26 EST 2006
Dear Charles, Alina, Mark, Andrew, et. al...
I think we miss the gist of what these corals are...
They're colonies ... of individuals. The true age of the individuals
speaking in terms of telemers and actual physical age would be based on the age of
each individual as they were formed. This goes back to the earlier comment
that the age OF THE COLONY would be based on several individual markers,
possibly the genetics of individuals within the colony that mutate as their genes
are continuously replicated. We are not speaking of an organism composed of
individual cells (although we often slip into the thought of these as
individual creatures), rather, each individual polyp is an organisms unto itself,
and although they specialize and develop roles within the colony, they are
still individual organisms within a colonial "organism," and as such will have
ages based on when they were "born" at the axial tip, etc. Even though their
"birth" does not entail genetic recombination (heh, unless they start some
genetic aberration from too much time in the sun... ), it still would represent
their age in terms of how long the individual has existed, and how likely due
to continued mitosis they would be to develop mutations (an age marker of
sorts depending on environment and genetics).
I don't think we can say that the formation of individual polyps at the
axial tip is the same as watching our bodies grow new cells to make epithelium or
close wounds, in spite of the fact that all the polyps may all be
genetically identical. I would think that would be like asking an elementery school
class what their age (as a class) would be...
Just another 2 cents worth to the discussion.
_tdwyatt at aol.com_ (mailto:tdwyatt at aol.com)
<<In a message dated 1/20/2006 3:40:35 PM Eastern Standard Time,
peck at hawaii.edu writes:
> It seems to me that the "individual" in this case is any fragment or
> propagule that is physically separate from other propagules of the
> same clonal unit. Once we get into defining an individual coral by
> genetic components over time, it gets quite interesting - and
> complicated. Although a somewhat more absolute point is planula
> settlement - as noted, corals are annoyingly plastic.
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