Definition of INVADE 1 : to enter and spread within either normally (as in development) or abnormally (as in infection) often with harmful effects <protect the body from invading viruses> <branches of a nerve invade the skin area>
On Sun, May 27, 2012 at 10:59 PM, Matt Chew <[email protected]> wrote: > > We don’t need to have a linguistic discussion, because labeling a process > consisting of unintended arrival, survival and successful reproduction of > organisms an “invasion” is a conceptual, categorical error. That makes it > a philosophical discussion, but hardly an arcane one. I'll only use a few > terms borrowed from philosophy, and then only because they precisely > represent the necessary concepts. > > Whether deliberately or reflexively applied to biota, “invasion” denotes > biogeographical anomaly and connotes reprehensible, willful misbehavior. More > importantly, it always elides description or explanation and rushes to > judgment. There are understandable reasons for doing that; either we feel > threatened, or we sympathize with someone else who feels threatened, or we > project those feelings onto things that can’t feel threatened and feel > threatened on their behalf. All very human. The trouble, for present > purposes, is the space where the science of ecology can add anything unique > or valuable to the discussion is limited to the descriptive, explanatory > steps we skip over in the rush to judgment. > > > > Returning to cases, nobody who suddenly finds they can’t depend on all > locally procured truffles to be equally valuable needs an ecologist to > explain commercial value or truffle sorting. Folk taxonomy and practical > business acumen is sufficient to the task. Nor can an ecologist improve > the situation by simply echoing and reifying the truffle > hunter/dealer/buyer’s lament. Worse yet, claiming from a stance of > (supposed) scientific authority, “Chinese truffles are invading Europe” > makes that statement out to be a scientific assessment. It isn’t > scientific at all. It neither describes nor explains any actual phenomenon. > > > > It does, however, vaguely (and yes, pejoratively) lump the European advent > of Chinese truffles together with a broad range of reputedly deplorable > cases likewise labeled “invasive species.” It also incidentally serves to > distinguish the "bad" invaders from useful species celebrated for > economically or aesthetically comporting with proximate human objectives. > That's pretty ironic, because field crops are the only plants that > effectively occupy and hold territory while completely excluding all > others. Our mutualists are not called invasive, even when cultivating them > arguably meets defensible criteria for description as a biological > invasion. Nobody needs ecologists, ecology or an ecological education to > draw such categories. That's why the basic ideas involved were already > worked out in the 1830s. Explaining why they are still current among > ecologists is more of a puzzle. It all could have ended with Darwin, and > certainly should have ended with the "modern synthesis." > > > > No so-called “invasive” species is doing anything anomalous. None has any > capability to persist where it is unfit. None has any responsibility to > perish where it is fit simply because it is novel there by human standards. > None is responsible for issues of time or distance. Ecologists may, > retrospectively, be able to work out the details of why particular cases > proceeded in particular ways in particular places at particular times. What > we cannot say, in our roles as ecologists, is whether the dispersal events > leading to those cases should have occurred. > > > > We can, of course, apply personal preferences to cases and announce whether > we like them or not. But (contra the implications of Aldo Leopold’s ‘world > of wounds’) our preferences do not arise from an ecological education. > Neither does any privilege of holding or expressing them. If you prefer to > maximize beta diversity, fine; you may know what that shorthand means > because of an ecological education, but preferring it doesn’t follow from > knowing precisely how ecologists describe it. All you need to know is that > you like different “places” to be as different as possible. As an > ecologist, you should realize that the amounts and types of rapid traffic > bringing formerly isolated locations into practical contact renders such a > preference increasingly unrepresentative of the real world real plants and > animals live in. > > > > Beta diversity means nothing until you learn its definition. Lacking that > knowledge, you might envision something, but there is a low possibility > that anyone would randomly hit upon its accepted ecological meaning. > Unlike beta diversity, “invasion” is not a legitimate ecological term, or > even a useful shorthand. Invasion is a common concept with a longstanding > military meaning. It is useful as a metaphor because its meaning is stable. > Ecologists who protest that “invasion” has a specific, ecological meaning > wholly divested of its common metaphorical associations are mistaken. > Perhaps they are rationalizing our inability or unwillingness to (a) > construct a coherent, defensible ecological category or (b) abandon the > advantages of investing their personal valorization preferences with > scientific authority. > > > Several times I have been warned by thoughtful, well-intentioned ecologists > who acknowledge the categories native, alien and invasive are theoretically > weak (even empty) that repudiating them would be too costly--in terms of > lost societal and political influence--to contemplate. In my view, failing > to repudiate them will be costlier still. I suspect most of us still > haven't really thought about it much. > > > Matthew K Chew > Assistant Research Professor > Arizona State University School of Life Sciences > > ASU Center for Biology & Society > PO Box 873301 > Tempe, AZ 85287-3301 USA > Tel 480.965.8422 > Fax 480.965.8330 > [email protected] or [email protected] > http://cbs.asu.edu/people/profiles/chew.php > http://asu.academia.edu/MattChew -- Robert J. Miller Marine Science Institute University of California Santa Barbara Santa Barbara CA 93106-6150 (805) 893-6174
