Published online: 28 October 2004
Marine worm sports two kinds of 'eyes'

Emma Marris
Vertebrate and insect vision may have evolved from the same precursor.

Darwin famously realized that the eye would be a key test for his theory of
evolution by natural selection. He suggested gradual steps from an
"imperfect and simple" form, and modern scientists have no
trouble believing
that the eye evolved from a single light-detecting cell. But they disagree
over whether it evolved just once, or many times.

Now the miniscule marine worm Platynereis dumerilii, whose crude light
perception seems to have stood it in good stead for millennia, hints at an
answer to this question.

Its few light-sensing cells come in two types: one is of a type seen almost
exclusively in vertebrates, and one is seen in insects, according to a paper
in this week's Science. Could a worm like Platynereis have been the father
of the eye?

Full Text at Nature
http://www.nature.com/news/2004/041025//full/041025-18.html

Comment:
The same gene triggers growth of the eye in the fly or mouse or even human.
How does this gene fit into this worm's genome?

Posted by
Robert Karl Stonjek
---
þ RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info{at}bbsworld.com

---
 * RIMEGate(tm)V10.2áÿ* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 11/1/04 4:35:56 PM