Imagine a stable population in which a favorable new genotype has appeared and is increasing. That sure looks like selection FOR the new genotype to me. On the other hand, if we start with the same population and change the environment so some of the old genotypes no longer do well, I'd call that selection AGAINST those genotypes.
This is all just semantics. If confused, stick to "differential reproduction". Jane At 07:16 AM 7/13/2006, Malcolm McCallum wrote: >Am I understanding you correct? =20 >Natural Selection selects against unfavorable phenotypes. >Sexual Selection selects for favorable phenotypes. >=20 >=20 >=20 >VISIT HERPETOLOGICAL CONSERVATION AND BIOLOGY www.herpconbio.org = ><http://www.herpconbio.org>=20 >A New Journal Published in Partnership with Partners in Amphibian and = >Reptile Conservation >and the World Congress of Herpetology. >=20 >Malcolm L. McCallum >Assistant Professor >Department of Biological Sciences >Texas A&M University Texarkana >2600 Robison Rd. >Texarkana, TX 75501 >O: 1-903-223-3134 >H: 1-903-791-3843 >Homepage: https://www.eagle.tamut.edu/faculty/mmccallum/index.html >=20 > >________________________________ > >From: Ecological Society of America: grants, jobs, news on behalf of = >James J. Roper >Sent: Thu 7/13/2006 6:37 AM >To: ECOLOG-L@LISTSERV.UMD.EDU >Subject: Re: Maldaptation, Extinction and Natural selection > > > >But Wirt, > >Natural selection doesn't "cull" but rather it "favors." And selecting >"for" something is very different than selecting "against" something.=20 >Favoring a trait leads to adaptation. That is, those with a trait leave >more descendents. Even so, it is not that simple. At any rate, John >Endler does a wonderful job of clearing things up with "Natural >Selection in the Wild" and I highly recommend it for anyone who has not >read it, and, don't forget, "The Extended Phenotype" by Dawkins, that >should also be required reading. > > > Interpreting literally what I wrote leads to a condition that I = >normally rail > > against myself. Selection never selects "for" anything. Selection = >operates > > only as a culling mechanism, removing the least appropriate, least = >competitive > > phenotypes of the demic excess that currently fills the competitive = >arena. > > =20 >What the heck does "demic excess" really mean? > >Cheers, > >Jim ================================================================================================== "The whole person must have both the humility to nurture the Earth and the pride to go to Mars." --Wyn Wachhorst, The Dream of Spaceflight Jane Shevtsov co-founder, <http://www.worldbeyondborders.org/>World Beyond Borders visit my blog, <http://perceivingwholes.blogspot.com/>Perceiving Wholes "Perhaps one day... the world, our world, won't be upside down, and then any newborn human being will be welcome. Saying, "Welcome. Come. Come in. Enter. The entire earth will be your kingdom. Your legs will be your passport, valid forever."" --Eduardo Galeano, Latin American writer
