On May 18, 2011 8:46 PM, "bmolloy" <[EMAIL PROTECTED]> wrote: > > Greetings all, > Re whales "choosing" to return to the sea.
wow, i'm surprised a little by the reaction that proposition is getting. The statement seems > to turn natural selection on its head. i don't think so. >My understanding of evolution is that > it's a question of adapt or die out. this is an over-simplification. >As the environment changes the more > adaptable in a species live and thus reproduce ever more adaptable > offspring, while those that fail simply die off. this may well be one way that evolution occurs. almost certainly. but why couldn't a mutation occur which enables a creature to occupy a *new* niche, absent environmental pressure. > The changes are totally random, due to the chromosome scatter which occurs > with each birth i.e no offspring is an exact copy of its parent, hence each > is a mutation of some degree. Some of this mutation is adaptable, some > irrelevant, some not and some harmful. > If the mutation increases survivability in a changing environment the > possessor will survive to produce more offspring with similar mutational > trends. In this way we have species change. . . hmm. again, this over-simplifies things. in fact, i would suggest that it inverts evolution as much as anything i've said. many, if not most species occupy specific niches, living off a narrow spectrum of foods. sometimes a single, specific thing. how does that square with "survival of the 'fittest'"? does it represent an evolutionary cul de sac? or a choice? > The changes are incremental and often miniscule, occurring on time scales of > hundreds of thousands and even millions of years, hence the outcome surely > cannot be attributed to choice. not necessarily. in fact, the indications seem to be that very significant mutations can occur over much shorter timescales than what has been the conventional wisdom. which makes total sense IMO, because otherwise certain evolutionary changes become very hard to explain. for example, take the original proto-air breathers. those fish that had both gills and primitive lungs. where did those lungs come from? was there a tortuous process akin to ptolemy's planetary orbits, whereby these different tissues developed independently, to finally, in one last incremental mutation, become linked as a whole respiratory system? or instead, maybe there once was a little fish fetus with a mutation in its "switching" genes such that it remained in one growth phase longer than usual. regardless, we now have this fish that can obtain oxygen from the atmosphere as well as from water. plus these funky, overgrown fins. why does it ultimately leave the water? does it *have to* be that it did so out of necessity? or perhaps simply because it could? because it chose to? -------------- next part -------------- An HTML attachment was scrubbed... URL: /pipermail/attachments/20110520/67195ff8/attachment.html _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/sustainablelorgbiofuel Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (70,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/
