Background: The Mormon Metalmark (Apodemia mormo) species complex occurs as isolated and phenotypically variable colonies in dryland areas across western North America. Lange's Metalmark, A. m. langei, one of the 17 subspecies taxonomically recognized in the complex, is federally listed under the U.S. Endangered Species Act of 1973. Metalmark taxa have traditionally been described based on phenotypic and ecological characteristics, and it is unknown how well this nomenclature reflects their genetic and evolutionary distinctiveness. Genetic variation in six microsatellite loci and mitochondrial cytochrome oxidase subunit I sequence was used to assess the population structure of the A. mormo species complex across 69 localities, and to evaluate A. m. langei's qualifications as an Evolutionarily Significant Unit. Results: We discovered substantial genetic divergence within the species complex, especially across the Continental Divide, with population genetic structure corresponding more closely with geographic proximity and local isolation than with taxonomic divisions originally based on wing color and pattern characters. Lange's Metalmark was as genetically divergent as several other locally isolated populations in California, and even the unique phenotype that warranted subspecific and conservation status is reminiscent of the morphological variation found in some other populations. Conclusions: This study is the first genetic treatment of the A. mormo complex across western North America and potentially provides a foundation for reassessing the taxonomy of the group. Furthermore, these results illustrate the utility of molecular markers to aid in demarcation of biological units below the species level. From a conservation point of view, Apodemia mormo langei's diagnostic taxonomic characteristics may, by themselves, not support its evolutionary significance, which has implications for its formal listing as an Endangered Species.
|BMC Evolutionary Biology
|Published - Apr 25 2015
Bibliographical noteFunding Information:
We thank Jim Brock, Evi Buckner, Chuck and Cindy Harp, Dan Rubinoff, Eric Runquist, and Ray Stanford for additional collections, and the ‘All Leps’ campaign of the ‘Barcode of Life’ initiative of the University of Guelph, Ontario, for sequencing the ‘barcode’ fragment of mtDNA in these specimens. We thank Jennifer Frei, Betsy Radke, John Steiner and David Wright for permits to collect A. mormo langei; and Anthony Cognato, Becky Miller, and Robert Reed for field assistance at Antioch. We also thank all the people who contributed to the northern collections that are documented in detail in Proshek et al. , and Corey Davis for his advice on microsatellite genotyping of the additional material in the current study. Lab and field activities were funded by an NSERC Discovery Grant and a Hatch grant to Felix Sperling. Finally, we thank Boyd Mori for analytical assistance, and Bryan Brunet, Jason Dombroskie, Lisa Lumley, and Thomas Simonsen for advice and assistance in preparing this manuscript.
© 2015 Proshek et al.; licensee BioMed Central.
- Apodemia mormo langei
- Conservation prioritization
- Endangered species act
- Evolutionarily significant unit
- Mitochondrial DNA
- Population genetics
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics