rising@utzoo.uucp (Jim Rising) (03/16/89)
Carole, methinks that you are confusing proximate effects with ultimate causes. The specific examples that you cite presumably have evolved because they maximize the lifetime reproductive success of the individual males and/or females involved (there may be conflicts in their individual maxmizing strategies, as in the bears that you mention), as Gordon suggests. Individual maximizing behaviours may on occasion have the effect of reducing the overall productivity of the group, but this is incidental (except under very special conditions) to the evolution of the behaviour. It's sort of like saying that people have sex because it is fun. Well, proximally, that is the reason, but ultimately they were selected to have sex because it enhanced their individual fitness. Comparably, a male bear may attempt to kill young because they compete with him and perhaps his young for resources, and there is low probability that they are his own offspring. If this is the case, it increases his lifetime reproductive success, and it is irrelevant (to him) whether or not this is good for bears in general. In this case it is highly likely that it decreases the female's LRS--but that, too, is evolutionarily irrelevant, except that it would select for females who were able to protect their young. --Jim Rising -- Name: Jim Rising Mail: Dept. Zoology, Univ. Toronto, Toronto, Ontario, Canada M5S 1A1 UUCP: uunet!attcan!utzoo!rising BITNET: rising@utzoo.utoronto.bitnet