Phylogeny and Conservation

[James Francis Lyons-Weiler]

On Tue, 27 Jan 1998, Shueyi wrote:

> There seems to be at least a couple of threads spinning in reponse to my
> original reponse to Russell Seymour - less than I'd hoped but still fun.  Here
> are my personal thoughts on some of the threads:
>
>
> 2 - the evultionary uniqueness argument.  I do not really buy this argument.
> Building on my comments above - are some biological lineages more important
> than others?  Would I modify my assessment of  the conservation need of a
> living fossil over a more imperiled but less divergent species?  No.
> Importance is a judgement call, and is usually based on the interest that a
> species generates.
>
> 3 - the phylogenetic divergence at the population level approach.  Again, I
> don't buy into this as an optimal way to protect biodiversity.  The rhino
> example is pretty illustrative.  If an animal with a pretty open population
> structure like a rhino has diverged significantly at the population genetic
> level, then chances are that many other species that co-occur with the two
> populations have experienced similar pressures.  Is it really ethical to air-
> lift out the rhinos and allow the diversity of one or another of these
> communities to become extinct?  No.  A better approach would be to use a
> targeting system that differentiates amoung the environmental gradients that
> produced the divergence, and to select targets (entire communities) that
> capture the other 100,000 or so lineages in addition to the rhino.  There is
> nothing in my ethical background that says that a rhino is more important than
> an owlfly.  Wasting resources to conserve populations of cool giant
> vertebrates is certainly not ethical if those resources could have been used
> to conserve the entire commuity - saving the rhino and much, much more.

        That position presumes that you have that option.  If the
        rhino populations have a 90% chance of being decimated,
        it seem more unethical to allow them to be destroyed while
        conservation biologists and community ecologists get around
        to selecting targets.

>
> And finaly, I loved 99% of Stuart G. Poss post - with one exception of course.
> Measuring relative species richness alone is not really a great way to select
> targets.  For example, in Indiana caves support very low diversity
> communities, but almost 30% of the community of 20-30 species may be endemic
> to a "cave-shed".  Certain botanical communities are likewise species poor but
> highly endemic - Alabama glades come to mind.  That's why I love targeting
> communities, because the caves of the Lost River system in Indiana support a
> different community than do the caves in the Mitchell Karst Plain, just 15
> miles away.  Between the systems there is about a 40% species turn over, but
> within the each geological formation the communities are reasonably
> consistent.  Thus, we target a few caves in both systems to capture all
> species of both community types.

        This position is identical to the phylogenetic unqiueness
        argument.

        James LW