Re: Alpha taxonomic drought & molecular meanderings
- Subject: Re: Alpha taxonomic drought & molecular meanderings
- From: &* R* <c*@ecoanalysts.com>
- Date: Mon, 21 Jul 2008 16:38:28 -0700
This is a really important
issue. The same thing is happening in the zoological realm as well. There is a
big misconception that genes are all you need. Taxonomy and systematics is
being forced into purely molecular based research, ignoring the ecological and morphological
aspects. Genes are but one tool (and a very good tool) in the tool box for identifying
organisms. The problems are as follows: 1.
Less than one tenth
of one percent of the species of the world have had their genes sequenced. So,
this makes it difficult to define taxa. 2.
Morphological
identifications are used to identify the organisms before they are sequenced,
so despite what some genetic only proponents say, you still need morphology to
have a starting point. 3.
It is a very rare thing
that any more than one or two individuals from a population are sequenced. This
often results in two or more populations called out as separate species, when
no one really knows what the inherit genetic variability of the species is in
the first place. This is painfully obvious in groups like the naked mole rats
of Africa and the Middle east which are morphologically indistinguishable, yet
molecularly can be separated into two or three species up to 50% genetically
different, verses the Hawaiian fruit flies which morphologically, behaviorally,
and ecologically can be separated into several well reproductively isolated
species (they literally cannot eat the same food, cannot live in the same
humidity, are sexually active at different times of the year, and live at
different altitudes), yet genetically they are less than 1% different. 4.
I am an associate
editor for an international zoological journal, and I am always receiving and
rejecting genetic papers where the researcher(s) did not deposit any specimens.
One of the tenants of the scientific method is reproducibility. Anyone should
be able to reproduce the results of someone else’s experiment. It amazes me how
often some genetics type will revise a genus, family, or species group, but
does not deposit any specimens in a museum. If I cannot go to the museum, find
their material and recreate their work, it is not science. 5.
Genetic barcoding and
Phylocode are also problematic. The vast
majority of my professional work and the work of my colleagues is
bioassessment, in which we use invertebrate community structure as a meter
stick of habitat health functionality. This type of habitat assessment is far
more accurate and precise at measuring habitat functionality then chemical
testing, because you are gauging the suitability and health of the habitat
using the organisms that are actually using the habitat: organisms that are
adapted to a given habitat or niche. I conduct this work in aquatic and
terrestrial habitats. What does this have to do with the classification debate?
The traditional Linnaean classifications provide us with the means of
understanding the ecology of the habitats we study. Certain orders, families,
genera and species in my quantitative samples have certain ecological meaning.
I can take a one square meter sample from a river, for example, and depending
on what taxa are there, I can tell you what metals and pollutants are present,
what nutrients, what the dissolved oxygen levels are, what the flow regime is,
how long an impacted site will take to recover, or if a restored habitat is
beginning to function naturally, how clean the water is, etcetera. Different
species, genera, and families of invertebrates mean very different things
ecologically. I could give dozens of general, and hundreds of specific examples.
Certain subfamilies of flies in the family Dixidae will tell you different
things than others. Different mayfly genera will give you different information
concerning heavy metals. Different midge genera will tell you what type of
nutrient loading (if any) is occurring in a given site. My beloved crustaceans
at order level can tell me about pesticide contamination in certain areas. Most
larval insects cannot be identified beyond family or genus level, yet they are
important ecological indicators of water quality! Furthermore, I need
dichotomous keys to orders, families, genera and species to identify the
organisms in my samples, and some of these samples may harbor more than 10,000
individual organisms. I need taxonomical hierarchy to identify my specimens. There
is an international bioassessment industry (I work all over the world), borne
of the desire for clean water, clean soil and clean air, as well as natural and
restored wildlife habitat, that relies on Linnaean taxonomy. Therefore, to
those of us who work in this field much of phyllocode, barcoding and least inclusive
taxonomic units are of little use, and to some of us in this industry represent
"ivory tower thinking". Organisms are a function of their
environment. Their taxonomy, in terms of their biology and ecology, are of far
greater significance to the general public who wants clean water, clean air,
and a healthy environment. If you take an organism out of its environment, and
reduce it to a mere terminus on a line, you may risk losing everything that
made it what it is. Just my two cents worth! I hope
that I have not strayed! But why do we collect these amazing plant? For their
genes or to appreciate their beauty and complexity? Happy days, Christopher D. Christopher Rogers Senior Invertebrate Ecologist/
Taxonomist ((,///////////=======< EcoAnalysts,
Inc. 1.530.756.4481 1.530. 383.4798 (cell) 1307 "L" Street Davis, CA 95616 USA ŸInvertebrate
Taxonomy ŸEndangered
Species ŸEcological
Studies ŸBioassessment ŸInvasive
Species ŸPlankton ŸPhycology Moscow, Idaho Ÿ Bozeman, Montana Ÿ Davis, California Ÿ Joplin, Missouri Selinsgrove, Pennsylvania ecoanalysts.com From:
aroid-l-bounces@gizmoworks.com [mailto:aroid-l-bounces@gizmoworks.com] On
Behalf Of Peter Boyce Dear Leland, Well, where I live unless there is a
change in education policy to imbue those few (and it is FEW) students with
some botanical aptitude, to gain knowledge of the basic building blocks of
botany, notably comparative morphology, ecology & geomorphology, the
spectre of no wide-experience field botanists, already a fact in many parts of
Asia, will become a region-wide problem. In fact the whole of taxonomy,
let alone systematics, is in danger of slipping off the curriculum in
universities throughout the region such that only the minute hard-core
(essentially botanically hard-wired) folks will make it through and continue.
The problem then will be that there are increasingly fewer jobs that call for
taxonomic expertise such that those few that wish to remain in the field
usually end up earning a living doing something at the best only tangentially
associated with their passion. Of course the irony is that there has never
been a greater need for taxonomic expertise in order to make the rational
decisions required to protect the remaining tropical habitats. Curiously, I am not anywhere near as
doubtful or indeed pessimistic about the increasing use of molecular data and
also don't altogether agree with the total genome argument. Regarding the
function of various parts of the molecular code, in recent years there has been
made enormous strides in understanding what various coding regions 'do' such
that the link with this and evo-devo is now a well established area of
scientific exploration. Of course some of these areas are ferociously expensive
but with molecular extraction methodologies and analyses programmes increasingly
simplified costs are dropping such that even quite sophisticated extraction and
analyses methodologies are well within the budget of even quite modest research
establishments. Regarding the usefulness of molecular data,
especially vis-a-vis the ability of the molecular practitioners to actually
identify the organisms they are studying, yes, I agree, that still far too many
molecular research outputs are the product of lab rats without any practical
field training and worse are oftentimes undertaken without or with only minimal
taxonomic cross fertilization. However, that situation is fast becoming history
as more and more multi-author research outputs based on sound alpha-taxonomy,
with the molecular toolbox being opened only once a decent 'traditional'
taxonomy is established and is testable. This is much the approach we are
using, with a multi-stranded project that is investigating alpha-tax. and then
phylogentics and then using the phylogenies to investigate spatial evolution,
etc. We have been very fotunate to find good students who are willing to spend
the necessary field time as part of their molecular-based research and as a
result have a much more complete biological research toolbox. Cheers Peter |
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