C'mon, Bill S,
It sounds like you're advocating rational policy based on
case-by-case evaluation with regard to consensus values. Where ya gonna get
with that?
Martin Meiss
2010/5/11 William Silvert <cien...@silvert.org>
> Although Jim Crants in a later post raised questions about whether by being
> fuzzy we risk avoiding responsible for human actions, I have to take issue
> with Roper's definitions. In large part this is because in some cases the
> distinction between humans and (other) animals is not relevant.
>
> Clearly in cases like the introduction of the rabbit to Australia we have a
> clear case of introduction, 100% in fuzzy terms. But consider the following
> cases:
>
> When American Bison migrate they disperse parasites and disease organisms,
> clearly this is a natural process.
>
> When Bison are depleted due to human depredation they may travel in search
> of mates, again dispersing parasites and disease organisms.
>
> Indians used to stampede Bison over cliffs as a means of hunting them, the
> survivors may flee and disperse parasites and disease organisms.
>
> Cattle grazing in the lands where Bison used to be plentiful may disperse
> parasites and disease organisms in the same way.
>
> Human herders following the cattle may disperse parasites and disease
> organisms on their clothing.
>
> And so on. Are nomadic tribes totally different from migrating animals?
>
> Crants later writes that "Invasive species biology loses most of its social
> relevance if native and exotic species are not ecologically
> distinguishable." but I do not think that we need to draw sharp lines
> between them. Migrations can be blocked by fences and roads, nomads may be
> confined within national boundaries. I don't think that invasive species
> biology requires that every species be either totally invasive or totally
> natural. And imagine what would happen if some exotic species that we blamed
> on ballast water transport turned out to arrive via a parasitic life stage
> on some migratory fish! All those papers to be withdrawn!
>
> One of the greatest invasions in ecological history occurred when the
> Mediterranean connected to the Atlantic Ocean. How fundamentally different
> is that from the opening of the Suez or Panama canals?
>
> Bill Silvert
>
> ----- Original Message ----- From: "James J. Roper" <jjro...@gmail.com>
>
> To: <ECOLOG-L@LISTSERV.UMD.EDU>
> Sent: segunda-feira, 10 de Maio de 2010 22:52
>
> Subject: Re: [ECOLOG-L] Ecology Terminology and associated phenomena
> Colonizing species etc
>
>
> But that question is easy to answer. If humans put the species in a place
>> or it arrived in a place that it would not have gotten to on its own, then
>> it is introduced, otherwise it is native or natural.
>> James Crants wrote on 10-May-10 12:51:
>>
>>>
>>> In the discussion off-forum, we were unable to come to any conclusions
>>> because we could not agree on answer to even the most fundamental
>>> question:
>>> is the distinction between exotic and native species ecologically
>>> meaningful? If you can't agree on that, there's no point in going on to
>>> ask
>>> whether there's such a thing as an invasive exotic species, whethere
>>> invasive exotics are a problem, and what, if anything, we should do about
>>> it.
>>>
>>
