Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!think!husc6!necntc!adelie!cdx39!jc From: jc@cdx39.UUCP (John Chambers) Newsgroups: sci.bio Subject: Re: The Red Queen Message-ID: <530@cdx39.UUCP> Date: Mon, 22-Dec-86 17:00:30 EST Article-I.D.: cdx39.530 Posted: Mon Dec 22 17:00:30 1986 Date-Received: Tue, 23-Dec-86 21:41:06 EST References: <741@aecom.UUCP> <925@husc6.UUCP> Distribution: na Organization: Codex Corp, a division of Motorola; Canton, MA, USA Lines: 31 Summary: remember random mutations... > >It has often been argued that biological change (evolution, I daresay) > >can occur even in the absence of environmental change. To some this has > >been used to discredit the entire evolutionary scenario. Anyone that argues that environmental changes are necessary to drive evolution is simply ignorant of the low-level mechanisms. Consider the scenario: A stray alpha particle comes zipping along, smashes through the fringes of a DNA helix, and when the electrons settle down again, a nucleotide or two have been changed. About 3 times out of each billion such occurrences, this is in a cell that produces a sperm or ovum, and the change is passed on to offspring. Furthermore, there's no problem coming up with 'constant' features of the environment that exert selective pressures. One such is called 'predators'. Even if the predators were unchanging, they would still select for avoidance capabilities in a prey species. Alpha particles and predators are part of the environment of all living creatures. [OK, a flying alpha particle isn't a feature of a 'constant' environment. But in that sense, there is no evolution in a truly constant environment, because everything is at absolute zero and there is no life.] -- John M Chambers Phone: 617/364-2000x7304 Email: ...{adelie,bu-cs,harvax,inmet,mcsbos,mit-eddie,mot[bos]}!cdx39!{jc,news,root,usenet,uucp} Smail: Codex Corporation; Mailstop C1-30; 20 Cabot Blvd; Mansfield MA 02048-1193 Clever-Saying: For job offers, call (617)484-6393 evenings and weekends.