Undue concern about morphospecies?

Richard Jensen rjensen at SAINTMARYS.EDU
Thu Jan 7 14:25:43 CST 1999


Peter Rauch wrote:

> [was] Re: (no subject)
> Your points (about lack of alternatives) are of course fine and
> well-taken. My point, however, was not intended to amuse, so much as to
>

sorry, I meant amusing in the sense of  diverting or absorbing, not in the
sense of being funny.

> > ...  Interestingly, when I asked them how they determined which
> > specimens they used to identify their samples, they had to admit that
> > they used a morphological criterion to establish the pooled samples
> > for their analyses.
>
> Hopefully, they also addresses what they felt were the consequences of
> "pooling" data of somewhat unknown meaning/content... ?

As an example, in an attempt to quantify gene frequencies in a population,
individuals were sampled randomly and the data pooled to allow calculation
of frequencies of each putative allele.  This whole venture, however, was
based on the assumption that the morphologically defined individuals sampled
all belonged to the same species.

>
>
> > I will be the first to admit that the morphospecies is not necessarily
> > the best concept to use for evolutionary studies, but when one is
> > conducting biodiversity surveys, I see little in the way of a
> > *practical* alternative.
>
> Yes, "practicality" looms large here (mostly thanks to our concerns to
> protect the environment). The unamusing issue is to make sure that those
> who must use biodiversity surveys (the "consumers" of the products, if
> you will) do so with adequate appreciation of what it means to be using
> possibly "not the best concept".

One thing we need to make clear is that all "consumers" understand the
necessity for the use of different species concepts.  The species concept
that is best for field identification may not be the same as the concept
that is best for evolutionary studies.  For example, throughout its range in
North America, the common red oak is a morphologically well-defined entity.
However, I would not argue that populations of this taxon in New England
belong to the same evolutionary species as do populations from western
Kentucky.  This, of course, opens up the entire question of what a species
is; why don't I recognize the New England and western Kentucky populations
as different species?  Well, while these populations have experienced
different evolutionary histories (perhaps by virtue of local introgression
with different species of oaks), there is no diagnosable character to allow
recognition as different species.... and so it goes.

> I think it is even more important to be prepared to address this issue
> (of uncertainty about what those observed units ("morphospecies") really
> mean in a diversity study or survey) when the study/survey is being
> challenged by those "consumers" whose goal it is to discredit the
> studies/surveys so that commerce and industry can progress unfettered by
> concerns for environmental protection, especially ESA (in the U.S., for
> example), "nonsense" and "hassle", as they seem to perceive it.

This is why we have to get the consumers to recognize that we biologists are
not disagreeing when some of us prefer morphological species concepts and
others prefer genetic or evolutionary species concepts.  I would argue that
our goals are different in some fundamentally important ways.  Use of a
morphospecies concept porbably provides a conservative estimate of
biodiversity.  There is nothing that should prevent us from recognizing that
in many cases, a single morphospecies may consist of populations that are
genetically different and therefore warrant protection in their own right.

--
Richard J. Jensen              TEL: 219-284-4674
Department of Biology      FAX: 219-284-4716
Saint Mary's College         E-mail: rjensen at saintmarys.edu
Notre Dame, IN  46556     http://www.saintmarys.edu/~rjensen




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