[Taxacom] Justifying species?

Derek Sikes ffdss at uaf.edu
Sat Feb 16 21:16:38 CST 2008


Another good paper with a similar approach is:

Johnson JB, Dowling TE, Belk MC (2004) Neglected taxonomy of rare  
desert fishes: Congruent evidence of two species of Leatherside chub.  
Systematic Biology 53(6):841–855

I wouldn't say this approach is common but it is increasing in  
frequency.

-Derek


On Feb 16, 2008, at 5:47 PM, Bob Mesibov wrote:

> In this recent paper:
>
> Palmer, C.M., Trueman, J.H. & Yeates, D.K. 2007.  Systematics of the
> Apteropanorpidae (Insecta : Mecoptera) based on morphological and
> molecular evidence. Invertebrate Systematics 21(6): 589-612.
>
> the authors report what seems to be a routine systematic exercise:
> cladistic analysis of a 36-character morphology dataset, COI sequence
> data, and a combined morph/mol dataset, from 21 sampled populations  
> of a
> genus with two described species.
>
> My query for the TAXACOM list is: is what follows also becoming  
> routine
> in systematics, or is it unusual?
>
> What the authors do next is review their results in the light of at
> least 6 different species concepts. For example, cladistic analysis
> identifies a lowland clade of this mainly mountain-dwelling taxon.  
> These
> lowland populations have a distinct genitalic morphology, which  
> 'agrees
> with the potentially interbreeding biological species criterion of de
> Queiroz (1988)'. 'As members of this clade also form a distinct  
> cluster
> of haplotypes, and form a diagnosable monophyletic group, this clade
> also conforms to the genotypic cluster species definition of Mallet
> (1995), and the autapomorphic (Donoghue 1985) and diagnosable
> phylogenetic (Eldredge and Cracraft 1980; Cracraft 1983; Nixon and
> Wheeler 1990) species concepts. These populations also inhabit a
> different altitudinal range from all other members of the family, and
> are therefore congruent with the ecological species concept of Van  
> Valen
> (1976), and the adaptive zone criterion of de Queiroz (1998). These
> populations are therefore regarded as a distinct, undescribed species'
>
> which the authors go on to describe in the formal taxonomic section of
> their paper. They also describe a second new species because
>
> 'Adults of the population from Hartz Peak possess a unique combination
> of morphological characters... Males from Hartz Peak also possess
> distinct, readily diagnosable, genitalic autapomorphies... These
> features of the genitalia indicate that this population is
> reproductively isolated from all others. The haplotype of the Hartz  
> Peak
> population is also different from that of all other members of the
> family, and constitutes its own, well-supported clade. The Hartz Peak
> population therefore meets the biological species concept,  
> autapomorphic
> and diagnosable phylogenetic species concepts, and genotypic species
> definition, and is regarded as a separate, undescribed species.'
>
> Some (fill in the number of your choice here) years ago, a
> morphology-only taxonomist presented with the same 21 samples might  
> have
> erected the two new species on genitalic differences alone, either
> without worrying about species concepts or by assuming that genitalic
> difference means reproductive isolation means two new BSC species.
>
> Here we have taxonomists explicitly considering varied species  
> concepts
> and using their character evidence to build what I might call a
> 'defense' of their decision to erect new species. *In other words, the
> more species concepts the taxon fits, the greater the justification  
> for
> naming it a Linnean species.*
>
> I haven't seen this philosophical approach to erecting new species
> before. Is it becoming more common now?
> -- 
> Dr Robert Mesibov
> Honorary Research Associate, Queen Victoria Museum and Art Gallery
> and School of Zoology, University of Tasmania
> Contact: PO Box 101, Penguin, Tasmania, Australia 7316
> (03) 64371195; 61 3 64371195
>
> Australian millipedes checklist
> http://www.qvmag.tas.gov.au/zoology/millipedes/index.html
> Tasmanian multipedes
> http://www.qvmag.tas.gov.au/zoology/multipedes/mulintro.html
> Spatial data basics for Tasmania
> http://www.utas.edu.au/spatial/locations/index.html
> Biodiversity salvage blog
> http://biodiversitysalvage.blogspot.com
> ---
>
>
>
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++++++++++++++++++++++++++++++++++++++++++++++
Derek S. Sikes, Curator of Insects
Assistant Professor of Entomology
University of Alaska Museum
907 Yukon Drive
Fairbanks, AK   99775-6960

dsikes at alaska.edu
http://homepages.ucalgary.ca/~dsikes/sikes_lab.htm

phone: 907-474-6278
FAX: 907-474-5469


"Remember that Truth alone is the matter you are in Search after; and  
if you have been mistaken, let no Vanity reduce you to persist in  
your mistake." Henry Baker, London, 1785

University of Alaska Museum of the North -
http://www.uaf.edu/museum/
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