Pattern versus process in conservation

John Grehan jrg13 at PSU.EDU
Mon Jun 1 09:16:34 CDT 1998

In response to discussion by Russell Seymour on pattern vs process and

I would take the position that geographic distribution is essential for
conservation purposes, but rather than priviliging it over gene flow etc
(which would simply be reversing the binary opposition) I would see it as
both complementary and necessary. I agree with Russell that taxa are
geographically (and temporaly) localized entities, and thus defining taxa
for conservation purposes without specifying the spatiotemporal coordinates
is to treat taxa as spatiotemporally unrestricted entities. In the context
of this perspective, conservation is about the conservation of
biogeographic pattern and process.

There are some comments on this question in the forthcoming book
"Panbiogeography: tracking the history of life" which may be published
sometime later this year or early next.

Sincerely, John Grehan

>Dear All,
>Following a seminar in which I was flamed (or distinctly singed at least!)
>for suggesting that pattern (geographic distribution) is more important
>than process (gene flow, drift, speciation events, ?, etc) for conservation
>purposes I would like to gauge a broader set of opinions.
>My own interest is directed towards subspecific distribution of mammals. I
>argued that if subspecies (I use this term loosely to mean any uniquely
>diagnosable group within a species) are to be used as 'conservation units'
>it is the pattern of distribution which must be elucidated so that the
>ranges may be delimited and management directed accordingly.
>My understanding of the argument against me is essentially that it must be
>some kind of process (natural selection? hybridisation zones?) that causes
>the observed differences so it is this process that needs to be protected.
>The patterns we see now are simply transitory. Distributions seen in 1998
>are different to those of a century ago, a millenium ago or further back.
>Indeed, in many cases they may be different to a decade ago. Hence it is
>the process and not the patterns derived from the process that must be
>identified and measures implemented to protect it (the process) into the
>I understand this argument but isn't it detached from reality? Legislation
>is one of the few tools available to large scale conservation but it
>requires specifics. It needs names and defined ranges. To acquire special
>protection for a 'conservation unit' it needs some particulars attached to
>it - specifically a name (implying a diagnosable unit) and range.
>To me pattern implies process. If a unique morphology or widely diverging
>DNA sequence (or whatever) is found then a process is occurring. At this
>point in time it is pretty much irrelevant what that is. The thing to do is
>to take action to protect the whole system. This way by identifying and
>protecting the pattern you effectively protect the process too.
>Ultimately perhaps this is a matter of semantics as both approaches reach
>the same goal but it seems that the pragmatic approach, which will best
>suit the pathways of legislation and politics which need to be traversed,
>is the pattern approach. I am interested in your opinion.
>P.S. I have sent this message to TAXACOM and CONSBIO. Sorry if you get it
>Russell Seymour
>PhD Research Student
>Institute of Zoology            and     Durrell Institute of
>Zoological Society of London            Conservation and Ecology
>Regents Park                            University of Kent
>London                                  UK
>NW1  4RY
>Tel: + 44 (0)171 449 6621
>Fax: + 44 (0)171 586 2870

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