Thursday, September 30, 2010
Discussion Question 2 (History and Biodiversity pattern and process) comments due Oct 5th
In the near future it may be possible to identify any species from a small, non-destructive, DNA sample. Given this fact, and the fact that acquiring taxonomic expertise can take a lot of time and work, is the ability to identify and classify species a skill that every conservation biologist should possess?
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Even if we can identify species by analyzing their DNA, taxonomic expertise is still an important skill for conservation biologists to possess.
DNA barcoding is not a perfected technology. It is too variable and simple to stand alone in the identification of species. You may be able to take a DNA sample and identify the species it came from, but you can take a variety of samples from the same species or even from the same organism. Therefore, it is not sufficient to rely on DNA sampling as a way to define a species for conservation purposes. Genetic diversity is important to the overall health of a species, and when we use DNA barcoding to drive conservation movements, we risk eliminating that genetic diversity. It also draws the focus of species conservation to the genes of that species rather than to the species itself.
However, taxonomic methods are not perfect either. There are so many ways to define a species. Some methods define a species too broadly, others too narrowly, so that when you are trying to conserve a species you could be mating two very similar species and thereby destroying the species you were trying to conserve.
If used in tandem, taxonomy and DNA barcoding could be checks on each other. Conservation biologists could have more accuracy if they were able to identify a species in two ways. DNA barcoding would also allow a species data base to be formed and initiate a greater understanding of the diversity that exists within a species. It could speed up some biodiversity assessments and allow taxonomists to define species with confidence.
Having every conservative biologist able to identify or classify species would be very helpful but it would also not be very easy to accomplish. It would be helpful if there was a single defined definition for species, but there is not. There are a number of different species concepts that are utilized by different parties depending on their different purposes or uses but it could also come down to what the taxonomist will determine as a new species. The problem with there not being a single concept for what is a species is that speciation may be too general or too broad. Species may be grouped together based on morphological features when they are actually different species, or new sub species may be named because of a difference in a certain stretch of DNA. Having speciation too narrowed may lead to losing focus on what species one is originally attempting to conserve. If new species are continuously being discovered or identified it brings into question where resources should be focused. At what point and in how many differences of DNA will it take before one no longer calls something a completely new species. Once a single definition of species is utilized by all conservation biologists and taxonomists then will it be most beneficial for all conservation biologists to possess taxonomic expertise to name and identify new species.
Although I agree that taxonomy is a valuable and necessary skill, I'm not sure that it is one every conservation ecologist must master. Instead I would argue that all conservation biologists should have a background in taxonomy and a portion of them should take the time and effort to become experts.
To quote Albert Einstein, "never memorize something you can look up." Although I dont think Einstein was talking referencing DNA barcoding in taxonomy, I think the gist of the argument is that you should not waste time and effort in memorizing answers that are easily available to you. If DNA sampling is generally effective in identifying a species I don't think it should be necessary for everyone to be an expert in taxonomy when their time, effort, and skill can be better allocated elsewhere.
Generally speaking taxonomic support is decreasing, which means it is harder to gain funds and support for research and learning. In addition, studying taxonomy requires access to specimen, large amounts of literature, multiple technical vocabularies, colleague's expertise, computers for data, as well as wet labs for genetic info. Clearly it is both expensive and time consuming to become and expert in taxonomy. Rather then train everyone as experts I think it would be smart to train some experts and use the extra time and money left over for other conservation biology projects such as studying endangered species, preserving land, helping wildlife conservation efforts.
REF:
Erwin, T. Hamilton, A. Pearson, D. Recovery Plan For the Endangered Taxonomy Profession. Bioscience, 61, 58-63. http://p8888-ucelinks.cdlib.org.proxy.library.ucsb.edu:2048/sfx_local?&url_ver=Z39.88-2004&url_ctx_fmt=info:ofi/fmt:kev:mtx:ctx&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.atitle=Recovery%20Plan%20for%20the%20Endangered%20Taxonomy%20Profession&rft.aufirst=David%20L%2E&rft.aulast=Pearson&rft.date=2011&rft.epage=63&rft.genre=article&rft.issn=0006-3568&rft.issue=1&rft.jtitle=BIOSCIENCE&rft.pages=58-63&rft.spage=58&rft.stitle=BIOSCIENCE&rft.volume=61&rfr_id=info:sid/www.isinet.com:WoK:WOS&rft.au=Hamilton%2C%20Andrew%20L%2E&rft.au=Erwin%2C%20Terry%20L%2E&rft_id=info:doi/10%2E1525%2Fbio%2E2011%2E61%2E1%2E11
It is necessary for every conservation biologist to be able to identify and classify species because this expertise will only better support identification through DNA bar coding. Both taxonomic approaches complement each other and yield the most thorough understanding of a species. Each can fill the gaps left by the other. Identification of inter- and intra- specific phenotype variability can be better understood and defined with DNA identification methods, however taxonomic expertise in the traditional sense should not be replaced with the DNA identification. Instead the DNA identification should be used as a tool, not as a replacement. The continual progress of each must be maintained in order for the most thorough understanding of species.
It was mentioned in the paper, "Species Delimitation: New Approaches for Discovering Diversity", that DNA barcoding would make taxonomy widely accessible to non-specialized conservationists. In this respect I think the DNA barcoding is worth investing time into because a wider range of expertise would be opened. On the other hand, with so many opinions from different fields, the work of taxonomists could be made more difficult.
From either side, the need for a balance between the two methods for classifying and identifying species is clear. The two should be used to complement each other.
Weins, J. (2007). Species Delimitation: New Approaches for Discovering Diversity. Syst Biol (2007) 56 (6): 875-878. doi: 10.1080/10635150701748506
http://web.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=9c3c4b36-2d6c-473a-830e-313dd9a2f53e%40sessionmgr13&vid=10&hid=17
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