Phylogeny and Conservation

Stuart G. Poss sgposs at WHALE.ST.USM.EDU
Thu Jan 29 15:08:10 CST 1998


In this thread it has been said:

>Phylogenetic considerations are
> rather a luxury when we don't even know, for most species, how many
> populations in which spatial arrangements will be most viable.

>Studing species richness, evolutionary relationships, and so on -  does not equal conservation.


Discussion of evolutionary processes and phylogeny are, for a variety of
reasons, seldom in the foreground of political motivation.  Such
discussion is rarely easily used to explain perspectives or justify
actions.  Surely, their complexity does not lend itself well to building
the necessary righteousness seemingly needed in our current highly
charged political environment to outcompete other potentially more
immediate or important adgendas.  However, let us not delude ourselves
into thinking that such issues are not pertinent.

When we speak of conservation, we are now faced largely with addressing
situations of dire immediacy in deciding which lineages shall continue
to evolve and which shall not.  Certainly, by preventing the wholesale
modification of areas encompassing relatively unique habitats, we can
expect more diversity and lineages to be concommitantly saved.  FOR
EVOLUTIONARY REASONS, it is important to include consideration of
contiguity of habitat and community structure, as well as the need to
conserve as much area and diversity of ecological communities as
possible.  Nonetheless, the "ecology" and "habitat requirements" of
species are themselves in the process of evolution and those that we now
see are the consequences of evolution, phylogeny.

As conservationists and evolutionary biologists, we make our choices and
must await the outcome of our experiments.  While we wait, we should not
assume that these communities of organisims, most individually or
collectively unique, remain in a state of stasis.  What we believe we
have saved today may be gone tomorrow, in part because we have failed to
fully understand or account for evolutionary processes.  A better
understanding of phylogeny can tell us much about these processes.

The situation in Florida provides a good example and it might be
reasonably argued that the strong collective conservation ethic among
its citizens has emerged in large measure from natural selection imposed
by massive environmental alteration.  While the total real estate and
conservation value now being saved is large, so have been the previous
adverse impacts on collective biodiversity.  I have seen estimates as
high as 30% of the fauna/flora of the state is non-native.  Unimpacted
virgin "habitat" is low, probably less than 5% by area.  Should we be
surprised by the equally strong conservation ethic in the San Francisco
Bay area, perhaps the most heavily impacted estuary in the world?
Should the efforts to bring back the Hudson or Cuyahoga Rivers from the
brink of total ecological collapse be seen out of historical context?
Perhaps more importantly, should we assume that increasingly large
expenditures of public funds will be enough to prevent future loss of
biodiversity, without using some of these resources to study what the
record of evolutionary history tells us about the taxa we we attempt
conserve?

Theodore Roosevelt made tremendous conservation efforts, which in terms
of today's real estate values dwarf most existing programs.  However,
much of what was once "conserved" is no longer secure.  Not only have
political perspectives and human impacts changed, but so has the
composition and extent of biodiversity in the areas once "conserved".
If we seek to prevent the loss of biodiversity, we must admit that our
viewpoint is severely limited by our relatively short life spans and our
own peculiar biology and evolutionary history, not to mention our
incredible collective ignorance of taxonomy and phylogeny that are
essential to an understanding of evolutionary process and the taxa
involved.

If as conservationists, we expect to understand the outcomes of our
experiments, we must be prepared to embrace the study of evolutionary
processes and of necessity, the science of phylogenetic reconstruction,
which attempts to develop a cummulative historical record of the
consequences of natural selection on organisms (observed outcomes
[=genotypes/phenotypes] over time).  These in turn govern the rules
dictating the evolution of the attributes of organisms collectively
(populations, subspecies, species, communities, and ecosystems) that we
often more directly associate with conservation efforts made during our
lifetimes.

We in Biology should not deny the importance of Physics simply because
the explanations we often use to account for biological phenomena need
not invoke the scale of explanation sought by physicists to be
meaningfully communicated.  Instead, we recognize that physical
principles influence the chemical behavior of molecules that influence
the physiology of organisms, whose evolution we are interested in
explaining.  Biologists have learned a great deal by pursuing a better
understanding of Physics.  There is a similar relationship between
Systematics (and more broadly Evolutionary Biology) and Conservation
Biology.

It has been said that those who ignore history are condemed to repeat
it. Ironically the evolutionary history of most linneages suggests that,
in the long run, the vast majority of species don't get an unlimited
number of chances to make such mistakes.  Since evolution is not a
cyclical process, we need an accurate historical context in order to
carefully assess our progress and our mistakes, as well as, to assess
the limitations and adaptability of the genetic heritage we hope to
conserve.

My comments are not meant to castigate, but rather to argue that we must
openly admit to the enormous complexity and uncertainty of the systems
we are talking about.  From my own perspective, I have been working on
the taxonomy and systematics of scorpaeniform fishes for over twenty
years, a minute (some 1,500 species), but interesting sliver of world
biodversity.  I must reluctantly confess I still know relatively little
about the subject.  However, I argue that knowing something about their
taxonomy and phylogeny tells me a great deal of value to their
conservation.

Nonetheless, setting the importance of the historical record of natural
selection and evolutionary processes to conservation aside, these
remarks of our colleagues provide an important lesson for those of us in
the community of taxonomists and systematists.  Namely, that we too must
evolve to alter the perceptions of our science.  We must seek more
effective ways to insure that the implications of the seemingly arcane
knowledge we have labored to discover are more widely understood and
utilized by those in other disciplines.

As taxonomists and systematists we must COLLECTIVELY develop and use new
and more sophisticated tools to conduct our research as well as to
disseminate the results of our labors.  There is no reason that we
should continue to be perceived as an early sister-group of other
sociological and scientific disciplines, a conservative evolutionary
lineage seemingly largely unchanged, little understood, and presumably
irrelevant.  While it has been many years since we first evolved as a
formal scientific discipline dedicated to studying AND CONSERVING world
biodiversity, we belong to a philosophical lineage that retains the
capacity to radiate into new and unexplored niches.

Let us reach out to colleagues studying other taxa and evolutionary
phenomena to make the importance of our discipline better understood.
Let us use the full breadth of perspectives that exist within our
community.  Not only do these perspectives range across all taxa, they
extend from the molecular to the ecosystem-wide.  We deal with events
that occur on a grain of sand to those that take place on a global
scale.  Phylogeny encompasses the history of evolutionary events that
occur in microseconds, as well as those measured only in geologic time.

The year 2000 is almost at hand.  Let us not wait to put Systematics
Agenda 2000 into action.  Let us make futher use of TAXACOM for this
purpose.  However, we must develop more coordinated use of the Internet
as a whole, as well as traditional media, that can be seen, used, and
appreciated by a broader segment of the public.  Many in our community
have much to be proud of already, but we can and must do much more.  As
our colleages point out, we don't have the luxury of time.

Stuart Poss

--
_____________________________________________________________________
Stuart G. Poss                       E-mail: sgposs at whale.st.usm.edu
Senior Research Scientist & Curator  Tel: (228)872-4238
Gulf Coast Research Laboratory       FAX: (228)872-4204
P.O. Box 7000
Ocean Springs, MS  39566-7000




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