From: Robert Owen (rowen@technologist.com)
Date: Thu Nov 04 1999 - 19:28:01 MST
The multiple evolutionary processes, all leading to the same result --
visual simulation of the environment by means of a manifold structure
we call an "eye" -- has always been of great interest. Now, however,
we have established a new discipline, "exobiology", to investigate a
much greater array of evolutionary outcomes in the exotic ecologies
expected on exoplanets.
Larry Klaes <lklaes@bbn.com> brought this article to my attention
and I noticed how it could serve to emphasize the inestimable scope
of evolutionary possibilities; this should encourage optimism as we
investigate the universe to determine the cosmic distribution of life.
Perhaps the most important inference is that a very large number of
processes seen potentially available to actualize diverse modes of
behavior which, at least analogically, we would not hesitate to to
interpret as exhibiting a high order of intelligence.
-o-o-o-o-o-o-
ITHACA, N.Y. -- An unusual type of eye -- resembling a tiny raspberry
and possibly following a design principle that vanished with the extinction
of trilobites hundreds of millions of years ago -- lives today in a parasitic
insect, Cornell University biologists report in the Nov. 5 issue of the journal
Science.
The compound eyes of most insects have many hundreds of lens facets,
each sampling only one small point in the insect's visual field, but the
composite lens eyes of strepsipteran insects have no more than 50 facets.
Fewer facets does not mean poorer vision, the Cornell biologists believe.
The strepsipteran lenses are larger, and each has about 100 receptors,
forming an individual retina behind each lens. According to the investigators,
this kind of eye is well equipped to sample not points but "chunks" of the
visual field, greatly improving the visual capabilities of these strange insects.
"No other insect that we know of has eyes quite like this," said Ron Hoy,
professor of neurobiology and behavior at Cornell and co-author, with
Cornell postdoctoral associates Elke Buschbeck and Birgit Ehmer, of
the Science report. "The only place one may see a comparable eye
structure is in the fossils of some kinds of trilobites," he says, referring
to the extinct arthropods that lived in shallow seas during the Paleozoic era.
-o-o-o-o-o-o-
Complete article at the Cornell News Service:
http://www.news.cornell.edu/releases/Nov99/new_eye.5.1.hrs.htm
=======================
Robert M. Owen
Director
The Orion Institute
57 W. Morgan Street
Brevard, NC 28712-3659 USA
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