Dear Bruce and others,

Interesting read indeed, and interesting reactions too. For the case you
could be interested, here are my two cents as the molecular biologist I once
was.

Molecular Biology is a powerful tool, but don't forget it is used by human
minds. To have some results you first have to choose a DNA fragment, then
sequence it from different sources and compare them. And thus, the first
problem: depending on the fragment you choose, you will obtain different
results. If you compare cit. C gen you get indeed all mankind togheter as a
species... beside all monkeys, and probably cows and mices too. On the other
hand, if you choose HLA genes, you can tell apart every human as different
from any other. Of course, there are all the intermediate possibilities you
may want, so what do you choose?

In Dr. Hebert interview it is cited like a great success that they could
distinguish the different species "with 100% accuracy" in a group of 200
lepidopterans. One must suppose that these species was previously defined by
morphological means, and then, what? Which is the role of molecular taxonomy
here? Furthermore, what would happened if they used a gen other than
cytochrome C oxidase? Easy: they would have obtained a quite different
grouping. How do they know cytochrome C oxidase gen was the right to use?
Easy: the results obtained was confirmed by morphological taxonomy...
Something fails here.

As to decide between conflictive hypothetical species, something alike
applies: if you want them to be different (or the opposite), you just have
to choose the appropiate sequence to prove your previous thought... Oh,
sorry, I forgot science was an objective and disappasionate matter. Anyway,
you could present all Cypraeas as a single group or distinguish between
every single C. tigris in the world.

About construction of phylogenetic trees, molecular biology presents also
similar problems as cladistic: depending on the method you choose to manage
the data, you will obtain several probable trees among which you must choose
using your knowledge and preferences (wait!, just like in morphological
taxonomy!). Since the data source must also be chosen by the researcher
(like in morphological taxonomy again) as mentioned, there's no guarantee
that results are much more "real"

It is however true that, once you have defined the species (by any mean),
molecular biology could readily assign any specimen to any previously
defined species through a simple test (just like clinic tests), which would
be very useful for Museums and collectors indeed, and it will be when it
could be affordable.

In the meanwhile, DNA sequencing provides just another set of data to take
into account in taxonomic disscussions, data which, like morphologic data,
must be handled with care.

Best regards,

Alfonso Pina
Málaga, Spain
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www.eumed.net/malakos