David R. Waddell wrote:
>> >And why has no
> >other similar mammal evolved green skin or fur,
>> I am not sure this is 100% true. I think there are
> monkeys with green pigments.
>> It is interesting that organisms that adapt to living
> in caves lose their visual pigments fairly rapidly. At
> least these pigments are probably bad to have if vision
> is no longer possible.
>
I agree. There would be no advantage in having a particular kind of
pigment, so there would be no selection pressure towards obtaining or
maintaining a pigment. In the case where there is no advantage at all to
pigmentation, the biological cost of producing pigment at the expense of
some other process may be a disadvantage.
> For temperate regions green pigment would definitely
> be bad in winter since it is a dead giveaway.
>>
Absolutely true (at least, if it snows regularly). For example, one
might expect that a coat which is 60% concealing in summer rough ground
and 60% concealing in winter rough ground might be more consistently
successful in fooling predators than mottled green (90% concealing in
summer, 10% concealing in winter), or the converse pure white -
depending on environment, of course.
Incidentally, does anyone know if domestic white rabbits are albinos or
domesticated wild (or selectively bred) white rabbits?
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Leighton
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The views expressed above are not necessarily those of the University of
Strathclyde. This is not surprising, as the University is a large
collection of buildings with no opinions of their own.
