Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site utastro.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!ihnp4!zehntel!hplabs!hao!seismo!ut-sally!utastro!ethan From: ethan@utastro.UUCP (Ethan Vishniac) Newsgroups: net.origins Subject: Re: Kinds Message-ID: <534@utastro.UUCP> Date: Fri, 14-Sep-84 16:35:13 EDT Article-I.D.: utastro.534 Posted: Fri Sep 14 16:35:13 1984 Date-Received: Tue, 25-Sep-84 02:31:10 EDT References: <286@uwmacc.UUCP> Organization: UTexas Astronomy Dept., Austin, Texas Lines: 34 [This space is blank] A while ago, in a fit of cynicism, I offered the following definitions: Variation within kinds - changes in the characteristics of any population of animal or plant which are well documented in the historical record. Variation between kinds - all others In the absence of any definition of "kind" other than "sharing a common ancestral population" I seem to have been more accurate than I thought. There is a recurrent problem in biology about the definition of species which other people have mentioned, i.e. what is a "species" anyhow? "Everyone" knows the answer to this in the sense that observers from different cultures will, in analyzing a given ecosystem, divide up creatures into the same sets of species. (I think this comparison has actually been done for American ornithologists and Papuan headhunters). However, inevitable ambiguities arise. From an evolutionary point of view this is normal. Speciation occurs as isolated breeding groups develope incompatible habits and biochemistry. There will always be examples of groups that are somewhat distinct, have slightly different ranges or habits, and do not *normally* interbreed. Many of them may never become truly distinct species. From a creationist point of view this ambiguity is more irritating. The definition suggested by Paul Dubois (I know he didn't make it up, but I forget his source), gets around this problem but only by making variation between "kinds" impossible by definition. Ethan Vishniac