Collembola, the biological species concept and the underestimation of global species richness

• Published in: Molecular ecology Vol. 22; no. 21; pp. 5382 - 5396
• Main Authors: Cicconardi, Francesco, Fanciulli, Pietro P., Emerson, Brent C.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.11.2013; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Arthropods; Arthropods - classification; Arthropods - genetics; Bayes Theorem; Biodiversity; Biological and medical sciences; Biological evolution; Cell Nucleus - genetics; Collembola; cryptic species; DNA, Mitochondrial - genetics; Evolutionary biology; Fundamental and applied biological sciences. Psychology; General aspects; Genetic diversity; Genetic Speciation; Genetic Variation; Genetics of eukaryotes. Biological and molecular evolution; Insecta; Invertebrates; Lepidocyrtus; Likelihood Functions; Linkage Disequilibrium; Mitochondrial DNA; molecular lineage; Molecular Sequence Data; Panama; Phylogeny; Population genetics, reproduction patterns; Sequence Analysis, DNA; Sympatry; Synecology; Central America; Panama; America; Concept; Lepidocyrtus; molecular lineage; Arthropoda; Insecta; Tropical zone; Panama; Cryptic species; Collembola; Invertebrata; Biodiversity; Species richness; biodiversity; cryptic species
• DOI: 10.1111/mec.12472
• ISSN: 0962-1083

Despite its ancient origin, global distribution and abundance in nearly all habitats, the class Collembola is comprised of only 8000 described species and is estimated to number no more than 50 000. Many morphologically defined species have broad geographical ranges that span continents, and recent molecular work has revealed high genetic diversity within species. However, the evolutionary significance of this genetic diversity is unknown. In this study, we sample five morphological species of the globally distributed genus Lepidocyrtus from 14 Panamanian sampling sites to characterize genetic diversity and test morphospecies against the biological species concept. Mitochondrial and nuclear DNA sequence data were analysed and a total of 58 molecular lineages revealed. Deep lineage diversification was recovered, with 30 molecular lineages estimated to have established more than 10 million years ago, and the origin almost all contemporary lineages preceding the onset of the Pleistocene (~2 Mya). Thirty‐four lineages were sampled in sympatry revealing unambiguous cosegregation of mitochondrial and nuclear DNA sequence variation, consistent with biological species. Species richness within the class Collembola and the geographical structure of this diversity are substantially misrepresented components of terrestrial animal biodiversity. We speculate that global species richness of Collembola could be at least an order of magnitude greater than a previous estimate of 50 000 species.