Hybrids and genera

[Stanley A. Gorodenski]

With my email software (Netscape 4.7) sometimes text I compose after a
right carrot character gets truncated after I submit it. Here goes
anyway.

Jeff Oliver wrote:
> 
> >Taxonomy is not intended to provide an accurate map of the evolutionary
> >process,
> 
> Again, if it could, why not?  Now there are hints of the Linnean hierarchy
> v. Phylogenetic taxonomy in the air...

I agree. To add to it, even though it (taxonomy) is not intended to
provide an accurate map of the evolutionary process, nevertheless the
Linnaean hierarchical classification system upon which contemporary
taxonomy is based lends one to easily interpret the structural placement
of species in this hierarchical structure as implying some sort of
evolutionary relationship, and many, it appears, interpret it this way.
In fact, as additional evidence is obtained on evolutionary
relationships (from things such as mitochondrial differences between
populations and species) a species sometimes will be moved from one
genus to another. The discussion about Cynthia that started this thread
is an example of this. The Linnaean system, I believe, increases the
difficulty of thinking about and determining evolutionary relationships
because these are constrained by the Linnaean classification system
itself. Given that we still do not fully understand the process of
speciation, do not have a working species concept that is accepted by
all researchers, and still do not know the evolutionary relationships of
all species (and never will for _all_ species), the relationships of
species within the Linnaean system will always have to be revised,
including some significant revisions at taxa higher than the genus
level. This is cumbersome and adds to confusion of citing species in the
literature. Maybe it is time to scrap the Linnaean classification system
and adopt something similar to the Phylocode concept. 

> 
> >Last, I disagree with the implication that there is an "objective biological
> >definition" of species.
> 
> So would I.  Who implied this?  Species concepts are just that: concepts.
> 

It may be that species concepts are concepts, and in fact they are by
definition, nevertheless they are very important to the study of biology
in general, evolutionary biology, and population genetics; having a good
working species concept is very important. For example, understanding
how the many bee species of the genus Perdita could have arisen,
understanding how a large number of cichlid fish (I believe) could have
arisen in some post glacial lakes, and understanding species swarms in
general is very difficult with the Biological Species Concept. Some
things are better understood with the Phylogenetic and Cohesive species
concepts. Sympatric speciation also was irreconcilable with the BSC, and
the BSC became a barrier, it seems, to explaining and understanding some
species relationships.

Stan

 
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