Path: news.f.de.plusline.net!news-fra1.dfn.de!news.visyn.net!news2.arglkargh.de!nuzba.szn.dk!pnx.dk!news.germany.com!out02a.usenetserver.com!news.usenetserver.com!in02.usenetserver.com!news.usenetserver.com!in03.usenetserver.com!news.usenetserver.com!hwmnpeer01.phx!news.highwinds-media.com!hw-filter.phx!newsfe12.phx.POSTED!53ab2750!not-for-mail Message-ID: <458C75F4.5404@cox.net> From: Larry Coon X-Mailer: Mozilla 3.01Gold (WinNT; I) MIME-Version: 1.0 Newsgroups: comp.databases.theory Subject: Re: Hierarchal vs Non-Hierarchal Interfaces to Biological Taxonomy References: <1166126176.587678.119920@t46g2000cwa.googlegroups.com> <4581D951.2571@assist.org> <458C44D8.5C1@cox.net> <1166827188.436596.159730@80g2000cwy.googlegroups.com> <1l_ih.36472$cz.536566@ursa-nb00s0.nbnet.nb.ca> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 44 Date: Fri, 22 Dec 2006 16:19:00 -0800 NNTP-Posting-Host: 68.225.236.214 X-Complaints-To: admin@cox.net X-Trace: newsfe12.phx 1166833140 68.225.236.214 (Fri, 22 Dec 2006 17:19:00 MST) NNTP-Posting-Date: Fri, 22 Dec 2006 17:19:00 MST Organization: Cox Xref: news.f.de.plusline.net comp.databases.theory:40532 Bob Badour wrote: Answering several distinct posts at once here... > >>Which opens the floor to: "How many species did you have > >>before B went extinct?" One. > > These kinds of questions are always interesting. And they > > often lead me to the same conclusion, which is that > > the concept being discussed is a construct of the > > human mind, and not of the natural world. The > > very idea of "species" is an abstraction. A useful > > one, but an abstraction nonetheless. Correct. > Here's an even better one: Suppose a retrovirus comes along that conveys > some fitness advantage so that it becomes ubiquitous among a species: > ducks for instance. Suppose as well that the virus crosses over from the > domesticated duck population into pigs and humans where it too becomes > ubiquitous. > > At that point, humans, ducks and pigs all share a unique recent > ancestor. Where does that put us in the taxonomy with ducks and pigs? Your "at that point, humans, ducks and pigs all share a unique recent ancestor" is an incorrect premise. A percentage of the human genome (I want to say 8%, but I don't remember for sure) came from outside organisms like virii, but that doesn't make them our ancestors. A facinating and related topic is mitochondria. There's evidence that it was orignally a separate organism that got incorporated into cells in a symbiotic relationship: cells provide the sugars that mitochondria need, and mitochondira provide the ATP that cells need. So a basic feature of eukariotic organisms (animals, plants and fungi) was acquired. Larry Coon University of California