Deborah Harrell <[EMAIL PROTECTED]> wrote
Horses actually do have color vision: they see blue
and yellow (and grey).
That is very interesting. Keith should be able to tell us what the
evolutionary advantages are.
In a `just so story' mode, I can tell you that yellow the color of the
direct sun and therefore useful for determining whether you are in
shade or not. Blue predominates in shade.
Moreover, I presume that blue in association with yellow enables you,
as a horse, to distingish among different shades of green and
therefore among different qualities of grass. Both sensor
capabilities would cause those horses, or proto-horses, that possessed
yellow/blue vision to reproduce better than those which lacked them.
Is there any evidence that this `just so story' is true? What are the
alternative possibilities?
I still do not know how to make an other-than-general argument
regarding evolutionary function.
More detailed stories like this regarding yellow and blue perception
come across to me as `just so stories'. What form of reasoning or set
of observations would enable me to think the arguments are more than a
nice, but non-scientific rhetoric -- such a nice rhetoric that I tend
to favor it even if I do not trust it?
(In
http://www.rattlesnake.com/notions/what-is-science.html
(I talk about science as a form of transcultural communication. That
is to say, I talk about it as a rhetoric with three methods: (1)
replicate the reasoning in the other individual, as with mathematics;
(2) replicate the observations; or (3) replicate the experiment; and
in the latter two cases, also replicate the reasoning. The psychology
is that people believe numinous experiences.)
--
Robert J. Chassell
[EMAIL PROTECTED] GnuPG Key ID: 004B4AC8
http://www.rattlesnake.com http://www.teak.cc
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