Mark, It seems likely that we will never have "precise" parameters for defining species. It is a misleading question in terms of importance, though many act as though it is of profound significance. A "species" in real life is dynamic but our *species concept* is, for now, a static one. Other problems include the fact that a species of *Romulea* is not analogous to a species of *Aster* and so on. Our understanding of populations, ideally a prerequisite for delimiting species, is ever-changing. A useful system of classification must be flexible enough to not fall apart every time new insights are published. We can expect our state of knowledge and interpretation to change constantly, but a taxonomy needs to weather such changes and not react (with name changes, e.g.) with every discovery. We must accept the fact that some species are more well-defined or "natural" than others and that some plants do not fit the pigeonholes to our satisfaction at all. This should be seen as a stimulation to our curiosity and not as a source of dismay. Dylan On 3 February 2013 12:07, Mark BROWN <brown.mark@wanadoo.fr> wrote: > What are the precise parameters for defining a species and now that > genetics are here? > > Mark > > > > > > > > Message du 03/02/13 19:51 > > De : "Hannon" > > A : "Pacific Bulb Society" > > Copie à : > > Objet : Re: [pbs] TAXONOMY DISCUSSION > > > > "*The days of the Mexican stand off between so called 'lumpers and > > splitters' is effectively soon to be at an end with these new tools and > > allowing an inarguable case, more often than not, to be made one way or > > another.*" > > > > Who would make the "inarguable case"? A consensus or a central authority? > > The arbiter is the scientific community, which derives much of its > strength > > from the heterodox nature of its members. Friction between the latter can > > be more productive than agreement. > > > > I don't think the problem of ranking taxa, ultimately a subjective > > necessity, can be resolved in a landscape of new information and evolving > > interpretations. Two botanists with a similar, comprehensive > understanding > > of a group may forward different and equally valid views on the > > organization of taxa into a formal classification. Such differences > provide > > a crucial forum for the improvement of phylogenies and taxonomy. > > > > > > Dylan > > _______________________________________________ > > pbs mailing list > > pbs@lists.ibiblio.org > > http://pacificbulbsociety.org/list.php > > http://pacificbulbsociety.org/pbswiki/ > > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ >