Failed species, innominate forms, and the vain search for species limits: cryptic diversity in dusky salamanders (Desmognathus) of eastern Tennessee
Article first published online: 27 JUN 2013
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Ecology and Evolution
Volume 3, Issue 8, pages 2547–2567, August 2013
How to Cite
Ecology and Evolution 2013; 3(8): 2547–2567
- Issue published online: 12 AUG 2013
- Article first published online: 27 JUN 2013
- Manuscript Accepted: 6 MAY 2013
- Manuscript Revised: 30 APR 2013
- Manuscript Received: 10 JAN 2013
- Blakeslee Fund for Genetics Research
- B. Elizabeth Horner Fund
- Smith College
Vol. 3, Issue 9, 3194, Article first published online: 8 SEP 2013
- Desmognathus ;
Cytochrome B sequences and allozymes reveal complex patterns of molecular variation in dusky salamander (Desmognathus) populations in eastern Tennessee. One group of allozymically distinctive populations, which we refer to as the Sinking Creek form (SCF), combines morphological attributes of Desmognathus fuscus with cytB sequences characteristic of Desmognathus carolinensis. This form is abruptly replaced by D. fuscus just north of Johnson City, TN with no evidence of either sympatry or gene exchange. To the south, allozymic markers indicate a broad zone of admixture with populations characterized by distinct cytB sequences and that may or may not be ultimately referable to Desmognathus conanti. A third distinctive group of populations, which we refer to as the Lemon Gap form (LGF), occurs in the foothills of the Great Smoky and southern Bald Mountains and exchanges genes with Desmognathus santeetlah along the escarpment of the Great Smokies, D. carolinensis in the southern Bald Mountains, and populations of a different haplotype clade in the Ridge and Valley. We treat all these as innominate forms that may represent “failed species,” recognizing that it may never be possible to reconcile species limits with patterns of phylogeny, morphology, and gene exchange in these salamanders.