Holotype fragment (botany)

Richard Pyle deepreef at BISHOPMUSEUM.ORG
Thu Jan 12 08:25:30 CST 2006

Thanks, Dick.

> Well...the first problem is that of knowing precisely what is meant by
> "genetically coherent individual organisms or colonies"

Regarding "genetically coherent individual organism or colonies", this is
something I just made up -- not prescribed by the ICZN Code.  I added
"genetically coherent" part for exclusivity, not inclusivity; "individual"
is the key word.  For example, a bee colony may consist of many, many
genetically identical clones, but (I believe) that name-bearing types are
selected as inviduals; not the colony as a whole.  So, just because what
amounts to two unambiguosly different individual organisms share and
identical genome, does not mean that the scope of the name-bearing type
includes all genetic clones.

> A museum specimen (for many plants, a complete individual)  is generally
> unambiguous: it constitutes the entire organism or a component (of the
> individual; e.g., a branch with leaves and flowers, or a branch
> with fruits, or
> simply a branch)  that reflects the diagnostic characters on
> which the name is
> based.

All of the above may also be true of zoological specimens as well.

> Could a mammalian name be based solely on the left hind
> foot of the animal?

The mammalian name would be based on (anchored to) the entire individual
organism from which the left hind foot was extracted -- regardless of
whether that left hind foot was all the original describer had access to, or
was all that remained after a fire burned down the museum collection.

> Could an insect name be based on just the thorax?

Yes, as above.

> Could a tapeworm
> name be based on a single segment?

Yes, as above.

> Given that plants and animals are so fundamentally different (in
> general), I
> think the answer is yes.  The trees I work with produce literally
> thousands of
> duplicate structures any one of which may be sufficient for
> identifying the
> species to which the individual is assigned.  Collecting the
> entire "genetically
> coherent" individual is not logical or practical.

Nobody ever said you had to collect the entire individual.  The point is
whether the name-bearing type is defined in terms of what gets preserved in
a Museum, vs. what the "limits" of an individual organism is/was.  I gather
from the discussion here that botanical names are anchored to a portion of
an organism as defined by a Museum specimen; whereas zoological names are
anchored to some cohesive unit of organism as defined by a taxonomist.  Both
kinds of definitions involve some level of ambiguity and subjectivity; but
it's not clear to me which involves more ambiguity, or whether there are
bioological reasons why one definition makes sense in one paradigm (plants
vs. animals) or the other.

For example, if there is a high frequency of cases involving ambiguity in
what constitutes a "genetically coherent individual organism" (e.g., a
single trees are often clones of many surrounding trees, and their roots may
even by physically connected -- analagous to a coral colony consisting of
many clonal and connected polyps), and a low frequency of such ambiguous
cases in the zoological world (seldom is it ambiguous where one insect
individual ends and the next begins), then perhaps there is a rational
foundation for defining the scope of a name-bearing type differently for
plants and animals.


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