Or maybe no advantage at all,the color red is one of the first colors to disappear the deeper you get, maybe they never had the need for that color since it doesn't exists at a certain depth. D.
On Jul 20, 10:31 pm, archytas <[email protected]> wrote: > I'm working on a paper for a conference on Darwin - something of an > excuse for myself and two colleagues to have a Xmas drink together in > Portugal. The topic, at least in working form, is 'simplexity and > tropical fish realism'. One or two in here raise their spines, > stickleback fashion, whenever teleology raises its head. Orn has > fought them off long and hard - my thanks for that. I found this > whilst brushing up a bit on Darwinism via the Stanford Encyclopedia of > Philosophy on-line. The relevance to teleology is in the last line, > though I've left the rest in as we should all know some prawns are > colour-blind to red. > > To take one startling example, he was able to test and confirm a > hypothesis that a group of males, with a color pattern that matched > that of the pebbles on the bottoms of the streams and ponds they > populated except for bright red spots, have that pattern because a > common predator in those populations, a prawn, is color blind for red. > Red spots did not put their possessors at a selective disadvantage, > and were attractors for mates. (Endler 1983, 173-190) We may refer to > this pattern of coloration as a complex adaptation that serves the > functions of predator avoidance and mate attraction. But what role do > those functions play in explaining why it is that the males in this > population have the coloration they do? > > This color pattern is an adaptation, as that term is used in > Darwinism, only if it is a production of natural selection (Williams > 1966 261; Brandon 1985; Burian 1983). In order for it to be a product > of natural selection, there must be an array of color variation > available in the genetic/developmental resources of the species wider > that this particular pattern but including this pattern. Which factors > are critical, then, in producing differential survival and > reproduction of guppies with this particular pattern? The answer would > seem to be the value-consequences this pattern has compared to others > available in promoting viability and reproduction. In popular parlance > (and the parlance favored by Darwin), this color pattern is good for > the male guppies that have it, and for their male offspring. > (Binswanger 1990; Brandon 1985; Lennox 2002). This answer strengthens > the ‘selected effects’ or ‘consequence etiology’ accounts of selection > explanations by stressing that selection ranges over value > differences. The reason for one among a number of color patterns > having a higher fitness value has to do with the value of that pattern > relative to the survival and reproductive success of its possessors. > > Selection explanations are, then, a particular kind of teleological > explanation, an explanation in which that for the sake of which a > trait is possessed, its valuable consequence, accounts for the trait's > differential perpetuation and maintenance in the population. > > Now that the teleology question is settled, can anyone explain what > advantage to the prawns it is to be colour blind to red? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups ""Minds Eye"" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/Minds-Eye?hl=en -~----------~----~----~----~------~----~------~--~---
