[cap-talk] Bee Eyes

[Mike Samuel]

2009/2/2 Steve Witham <sw at tiac.net>

> About charging into the valley of blindness, Jesus said, "If your right
> eye causes you to sin, pluck it out."  But upon consideration he said,
> "First remove the plank from your own eye."
>
> Evolution seems to have crossed the gap between compound and
> single eyes in both directions.  There's a fascinating variety of
> approaches including parabolic mirrors, corner reflectors,
> segment walls that retract under low light, and simple eyes wedged
> within compound eyes.  The eye of some flying insects, including the
> bee, has a fovea--an area in the middle that gets better resolution
> using larger lenses.
>
> http://en.wikipedia.org/wiki/Compound_eye
>
> I'm pretty sure the gene-activation signal for "form an eye here" is
> the same for humans, bees and octopi, erm,
>     While marveling at your own eye
>     give a thought to the octopi
>         whose optical nerves
>         straighten out all the curves
>     that cause blind spots for you and for I.
>

I thought mollusc and vertebrate eyes were a case of convergent evolution.
>From http://en.wikipedia.org/wiki/Evolution_of_the_eye
The different forms of eye in, for example, vertebrates and mollusks are
often cited as examples of parallel
evolution<http://en.wikipedia.org/wiki/Parallel_evolution>
.
and
At a cellular level, there appear to be two main "designs" of eyes, one
possessed by the protostomes
<http://en.wikipedia.org/wiki/Protostomes>(molluscs, annelid worms and
arthropods), the other by the deuterostomes
(chordates and echinoderms)





>
> MarkM says:
> >These have come up before on this list, and we've always concluded
> >(correctly IMO) that HCSs have no technical advantage over pure ocap
> systems
> >used with the Horton pattern. However, HCSs may provide the path through
> the
> >valley of blindness that allows us to reach the higher hill.
>
> By technical advantage you mean in terms of the kinds of effects you
> could achieve if starting from scratch.  But, migration also has its
> technical problems.  We need a capital-O notation for human effort.
>
>  --Steve
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