Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site cybvax0.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!qantel!dual!lll-crg!seismo!harvard!think!mit-eddie!cybvax0!mrh From: mrh@cybvax0.UUCP (Mike Huybensz) Newsgroups: net.origins Subject: Re: Why ain't life homogenized today? Message-ID: <752@cybvax0.UUCP> Date: Mon, 16-Sep-85 11:36:25 EDT Article-I.D.: cybvax0.752 Posted: Mon Sep 16 11:36:25 1985 Date-Received: Thu, 19-Sep-85 07:31:08 EDT References: <2649@vax4.fluke.UUCP> Reply-To: mrh@cybvax0.UUCP (Mike Huybensz) Distribution: net Organization: Cybermation, Inc., Cambridge, MA Lines: 38 In article <2649@vax4.fluke.UUCP> hopeful@fluke.UUCP (Buford Wanttruth) writes: > "WHY IS LIFE NOT HOMOGENOUS TODAY WITH > MYRIADS OF INTERGRADING FORMS MAKING CLASSIFICATION IMPOSSIBLE? Good question. There's a good answer too. Let's assume for the moment that you miscegenated with a sheep, and the ewe gave birth to your firstborn son, the smartest offspring a sheep ever had, and the wooliest offspring of any human ever. This new creature grows up into a fine example of thinghood, but has some problems. It can't compete well with either humans or sheep. The rams butt him away from the ewes, and he can't fight back because he hasn't big horns or enough brains to use tools. Human females laugh at him because he is too hairy and stupid. Your offspring will likely have less success at reproduction than if you had bred with something human. And thus you will have fewer grandchildren than if you had bred with something human. This is a general phenomenon, due to specialization. Offspring between two different specialists are not likely to be able to compete well with either parent species in parental habitats. Thus, it is beneficial to specializing organisms to stick to their own kind, and not waste their reproductive energies on mates that will produce inferior children. This is the driving evolutionary force producing barriers to reproduction between species. Assume for a moment that somehow two species have come about, and meet in a zone where hybridization takes place. Natural selection will favor individuals in both species which do not miscegenate, no matter what the reason (wrong smell, whatever.) These characteristics will be selected for, and spread throughout the populations, eventually forming the barriers to reproduction that we know today. This process is visible between quite a number of sibling species, such as the leopard frogs, various grasshoppers, white-footed and deer mice, voles, etc. Individuals from where the species overlap will not miscegenate. Individuals from where the species don't overlap will miscegenate. -- Mike Huybensz ...decvax!genrad!mit-eddie!cybvax0!mrh Brought to you by Super Global Mega Corp .com