Abstract

Species identities are best indicated by analyses of nuclear DNA which is the material representing the working points of evolution. Additional good indicators of species identities are those expression products of nuclear DNA which are least modified by environmental influence and, as a consequence, show the highest correlation with the genetical core information. Among expression products such as morphology, products of metabolism and ethological or ecological traits, morphology is rated here as indicator with the highest correlation. The use of morphology as most important accessory indicator is furthermore favored by the leading position it played in species descriptions over 280 years of taxonomic research. Focusing on the example of ants, the paper considers 13 studies with parallel application of mtDNA barcoding, analysis of nuclear DNA and application of Numeric Morphology-Based Alpha- Taxonomy (NUMOBAT). Selected were only studies based on sufficiently high within-species numbers of samples. With nuclear DNA and NUMOBAT used as objective and testable control systems, the average classification error of mtDNA barcoding per sample or individual was 16.8% over 10 genera with 66 species with the extremes ranging from 0 to 32%. Ancient hybridization is considered a much more likely cause for mtDNA mismatches in ants than incomplete lineage sorting.

Keywords:Species classification; Ants; mtDNA barcoding; Nuclear DNA; Morphology; Based numeric; Alpha-taxonomy