Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!samsung!uunet!amara!tom From: tom@amara.uucp (Tom Doehne) Newsgroups: sci.bio Subject: Re: Which animals are color blind ? Message-ID: Date: 17 Dec 89 00:17:39 GMT References: <8938@medusa.cs.purdue.edu> <25897473.1196@paris.ics.uci.edu> Sender: news@amara.UUCP Organization: Applied Dynamics Int'l, Ann Arbor Mi Lines: 23 In-reply-to: honig@ics.uci.edu's message of 15 Dec 89 22:47:15 GMT 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