Xref: utzoo sci.bio:2710 rec.pets:10987 Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!swrinde!emory!mephisto!mcnc!ecsvax.uncecs.edu!dukeac!wolves!ggw From: ggw@wolves.uucp (Gregory G. Woodbury) Newsgroups: sci.bio,rec.pets Subject: Re: What distinguishes a species? Summary: species is both genetic and ecological Message-ID: <1990Feb9.062446.923@wolves.uucp> Date: 9 Feb 90 06:24:46 GMT References: <22448@siemens.siemens.com> <202@53iss6.Waterloo.NCR.COM> <25520@gryphon.COM> <3251@hp-sdd.hp.com> <2285@uwm.edu> Reply-To: ggw@wolves.UUCP (Gregory G. Woodbury) Followup-To: sci.bio,rec.pets Organization: Wolves Den UNIX BBS Lines: 33 In article <2285@uwm.edu> debbie@csd4.csd.uwm.edu (Debbie Forest) writes: >In article <3251@hp-sdd.hp.com> andrea@hp-sdd.UUCP (Andrea K. Frankel) writes: >> >>Physical difficulties notwithstanding - if you (ahem) gathered sperm >>from a St. Bernard and artificially inseminated a Chihuahua in heat, >>you would get offspring which were themselves fertile. > >yes, all dogs are the same species. but why then aren't wolves in the >species too, since dogs and wolves can cross-breed? The simple case of cross-fertilization (with or without fertile offspring) is not sufficient to define a species. The other half of species definition is the ecological niche the new species occupies in comparison to the parent group. When an adaptive shift occurs which allows the offspring to occupy a niche which tends to isolate the new group from the old further adaptations in the new group can accelerate the isolation of the new species. Wolves and Dogs (canis lupus vs canis familiaris) occupy different niches in general, but not so different that contact is eliminated. Some purists would like to say that lupus and familiaris are "sub-species", but general usage has its effect as well. ------------- Just some additional fuel for the discussion to justify being in sci.bio ;-) -- Gregory G. Woodbury Sysop/owner Wolves Den UNIX BBS, Durham NC UUCP: ...dukcds!wolves!ggw ...dukeac!wolves!ggw [use the maps!] Domain: ggw@cds.duke.edu ggw@ac.duke.edu ggw%wolves@ac.duke.edu Phone: +1 919 493 1998 (Home) +1 919 684 6126 (Work) [The line eater is a boojum snark! ]