Re: limits of variation

GRMorton@aol.com
Tue, 1 Aug 1995 21:42:50 -0400

Art wrote:
>Chlorella is an algae, so we have not only produced a new species but a new
kingdom if Coelosphaerium is a bacteria! Someone needs to go back and read
the original paper. I have no confidence in a paper published in the Trans
Amer Geophy Union on transformation of algae! Someone is pulling someones leg
on this one!<<
^^^^^^
First off, I was not the one who said this was a bacteria. (at least I can't
find where I said that) I believe that it was Stephen Jones who said it was
a bacteria.

As to whether someone is pulling my leg, I have a copy of the EOS page that
this appears on. I am looking at it right now. I got it from the UTD library
(or the librarian got it and sent it to me.) It is under a section
"Bioluminescence, Zooplankton Orientation and Growth," It is EOS vol 64 No.
52, Dec. 27, 1983. p. 1102. Here is the entire abstract.
^^^^^^
Predator-mediated algal evolution in Chemostat culture

Martin E. Boraas (Center for Great Lakes Studies, University of Wisconsin at
Milwaukee, P.). 413, Milwaukee, Wi 53201)

An unidentified microflagellate specie (4-12 [mico]m) and Chlorella Prenodosa
(2-5 [micro]m) were grown at 25 C in mixed-species chemostats with constant
light and sterile, inorganic medium flow. The flagellate readily consumed
the algae and grew rapidly (doubling time ca. 6 h). Size distributions of
both species are shown in the Figure (area = biovolume). After an initial
oscillation (curves 1,2), the system apparently stabilized with both species
coexisting. The algal population now consisted of clusters of 4 to tens of
cells that were immune to predation by the flagellate (curve 3). The mean
cluster size then steadily decreased (curve 4) and stabilized at 4-8 cells
(curve 5). These, and other, observations support the hypothesis: (1) a
multicellular algal form was selected as a response to predation pressures,
(2) a minimum cluster size was selected due to nutrient competition (large
clusters have a smaller surface area per unite biomass) and (3) genetic,
morphological, and structural diversity of the system increased as a response
to predation. Flagellate predation influences both the genetics and the
dynamics of microalgal population."
^^^^^^^^^^^^
Boraas was the presider of this section when the talk was given. So I presume
he is no slouch in his field. The other papers on the EOS page are all
biological in nature and cover marine organisms. There is a fascinating
abstract on copepod ingestion and egg production. I hear Ron Howard is going
to make a movie on it. :-)

While I have not been directly in contact with Boraas, I have been in contact
with a guy who has been in contact with him. He is the one who told me about
the classification. That piece of information is not in the above abstract.
Apparently these things still are going strong. If someone knows this guy it
would be nice to get a direct report on the current status of the critters.

glenn