muttiah@cs.purdue.EDU (Ranjan Samuel Muttiah) (12/13/89)
Could some knowledgeable biologist on the net tell us which animals are color conscious and whether there were evolutionary reasons for this ? Thank You
honig@ics.uci.edu (David A. Honig) (12/16/89)
In article <8938@medusa.cs.purdue.edu> muttiah@cs.purdue.edu (Ranjan Samuel Muttiah) writes: > >Could some knowledgeable biologist on the net tell us which >animals are color conscious and whether there were evolutionary >reasons for this ? > >Thank You Well, I'm not trained as a biologist, but I do study vision. Color vision appears all over the animal kindom, with varying numbers of cone types (ie some animals are 'colorblind' but do discriminate some bcolors). Also, the spectral sensitivities of different animals differ (their best 'red' isn't ours; but there are people who have slightly different photopigments too.) Goldfish have color vision. Some primates have it, some don't. Reasons: Nocturnal animals tend not to, being entirely rod-based. The theory about primate color vision is that red/green discrimination is real useful if you spend your time looking for ripe fruit against foliage....but wouldn't you have to examine each species' niche to discover how color vision is useful? -- David A. Honig ... Paternalism is a first step towards totalitarian statism.
tom@amara.uucp (Tom Doehne) (12/17/89)
In article <25897473.1196@paris.ics.uci.edu> honig@ics.uci.edu (David A. Honig) writes: > Reasons: Nocturnal animals tend not to, being entirely rod-based. The > theory about primate color vision is that red/green discrimination is > real useful if you spend your time looking for ripe fruit against > foliage....but wouldn't you have to examine each species' niche to > discover how color vision is useful? We can't assume that all genetic variations are useful. It's enough that a mutation not be maladaptive, after all. Also, some traits may have been useful in an ancestor's environment, but not in the niche the organism currently occupies. Steven J. Gould has written often about the fallacy of appealing to adaptation to the present environment when explaining some trait. His "Urchin something something Storm" has some essays on this. -- -- Tom Doehne tom%amara.UUCP@mailgw.cc.umich.edu ...sharkey!amara!tom