Allopatry as a Gordian Knot for Taxonomists: Patterns of DNA Barcode Divergence in Arctic-Alpine Lepidoptera

Abstract

Many cold adapted species occur in both montane settings and in the subarctic. Their disjunct distributions create taxonomic complexity because there is no standardized method to establish whether their allopatric populations represent single or different species. This study employs DNA barcoding to gain new perspectives on the levels and patterns of sequence divergence among populations of 122 arctic-alpine species of Lepidoptera from the Alps, Fennoscandia and North America. It reveals intraspecific variability in the barcode region ranging from 0.00–10.08%. Eleven supposedly different species pairs or groups show close genetic similarity, suggesting possible synonymy in many cases. However, a total of 33 species show evidence of cryptic diversity as evidenced by the presence of lineages with over 2% maximum barcode divergence in Europe, in North America or between the two continents. Our study also reveals cases where taxonomic names have been used inconsistently between regions and exposes misidentifications. Overall, DNA barcodes have great potential to both increase taxonomic resolution and to make decisions concerning the taxonomic status of allopatric populations more objective.

Diversity, specificity and speciation in larval Diplostomidae (Platyhelminthes: Digenea) in the eyes of freshwater fish, as revealed by DNA barcodes

“…4), and the scale at which diplostomid species are sampled is not a significant predictor of CO1 NN ratios, once sampling effort is taken into account. Overall, the data provide additional evidence that the effect of spatial scale on species delineation and specimen identification using CO1 is small in many (Hebert et al, 2004;Lukhtanov et al, 2009;Mutanen et al, 2012;Huemer et al, 2014;Locke et al, 2015) if not all cases (Meyer and Paulay, 2005;Bergsten et al, 2012).…”

Study on Phylogenetic Status of Javan Plover Bird (Charadrius, Charadriidae, Charadriiformes) through DNA Barcoding Analysis

“…In some other bird groups, genetic divergence between species within a genus has a value that varies widely. DNA Barcoding is based on the 2003b; Mutanen et al, 2012), and the sister-bird species average found genetic distance of 5.1% (Klicka and Zink, 1997), 3.5% (Johns and Avise, 1998), and 4 % (Hebert et al, 2003a;Mutanen et al, 2012). In most mammal species average intraspecific divergence were less than 2-3% and interspecific distances within most genera were more than 3% (Luo et al, 2011).…”

Allopatric cryptic diversity in the alpine species complex Phtheochroa frigidana s. lat. (Lepidoptera: Tortricidae)

“…In such species the phylogenetic concept (Cracraft 1989) may be adopted and species concepts are rather based on diagnosability. To avoid artificial oversplitting, Mutanen et al (2012) suggested species status for allopatric populations with a divergence in two or more independent characters. We follow this compromise and reserve species status for five allopatric populations, supported by both morphological characters and DNA barcode divergence.…”

“…The taxonomy in many of these taxa is disputed and different species concepts have been applied by various authors. Modern molecular studies (Hebert et al 2003(Hebert et al , 2009) have helped to resolve some of the critical issues (Huemer & Hebert 2011;Huemer & Mutanen 2015), although others have remained unresolved (Mutanen et al 2012).…”