From ‘cryptic species’ to integrative taxonomy: an iterative process involving DNA sequences, morphology, and behaviour leads to the resurrection of Sepsis pyrrhosoma (Sepsidae: Diptera)

Abstract

R. (2010). From 'cryptic species' to integrative taxonomy: an iterative process involving DNA sequences, morphology, and behaviour leads to the resurrection of Sepsis pyrrhosoma (Sepsidae: Diptera). -Zoologica Scripta, 39, 51-61. The increased availability of DNA sequences has led to a surge of 'cryptic species' in the literature. These units are usually proposed based on finding genetically distinct lineages within species that were initially defined based on morphological characters. However, few authors attempt to confirm whether these 'cryptic' units are species and even fewer authors are explicit about which species concept is applied. Here, we use an example from Sepsidae (Diptera) to demonstrate how cryptic species can be validated by an iterative process involving several data sources and an evaluation of the data under different species concepts. A phylogeographic analysis based on 50 specimens for five species of the flavimana group revealed deep mitochondrial splits within Sepsis flavimana which was suggestive of a cryptic species. We resolve the initial conflict between DNA sequences and morphology by adding new morphological data as well as behavioural evidence and tests for reproductive isolation. One cryptic species is confirmed and Sepsis pyrrhosoma, a former synonym of S. flavimana, is here shown to be a valid species under most species concepts. We can thus document that the same data can lead to similar conclusions under conflicting concepts once different kinds of data are integrated.

A response to recent proposals for integrative taxonomy

“…Also, a considerable number of systematists have now begun to adopt the term 'integrative taxonomy' to frame their use of different lines of evidence for discovering and delimiting species (e.g. Mengual et al, 2006;Lanzone, Ojeda & Gallardo, 2007;Roe & Sperling, 2007;Alström et al, 2008;Fonseca, Derycke & Moens, 2008;Cardoso, Serrano & Vogler, 2009;Castroviejo-Fisher, Guayasamín & Kok, 2009a;Castroviejo-Fisher et al, 2009b;Gibbs, 2009;Puillandre et al, 2009;Vieites et al, 2009;Glaw et al, 2010;Lumley & Sperling, 2010;Tan et al, 2010;review by Schlick-Steiner et al, 2010). In general, most authors share the view that it is necessary to construct a more integrative species taxonomy that is able to handle evidence, data, and methods originally developed by other biological disciplines, such as population genetics, phylogeography, and phylogenetics.…”

Out of the deep: Cryptic speciation in a Neotropical gecko (Squamata, Phyllodactylidae) revealed by species delimitation methods

“…Despite the unquestionable value of those methods in assessing cryptic diversity (Leaché and Fujita, 2010), it is advisable to use independent morphological or ecological data to corroborate molecular-based hypotheses of cryptic diversification (Bauer et al, 2011;Burbrink et al, 2011;Sistrom et al, 2012). In this context, morphological data can be used to test the placement of individuals within the reconstructed molecular clades and evaluate the validity of such lineages (Hebert et al, 2004;Sistrom et al, 2013;Tan et al, 2010). This integrative approach can provide valuable support when delimiting 'candidate species' for conservation management strategies (Morando et al, 2003;Padial et al, 2010).…”

How many species are there in the subgenus Bursaphis (Hemiptera: Sternorrhyncha: Aphididae)? CO-I evidence

“…Therefore, ecological specificity is the most important feature when trying to classify living things, followed by morphological and molecular analyses [see Rakauskas (2009) for wider discussion]. The experience of the authors leads them to support the opinion that DNA barcoding is not a replacement for morphology-(and ecology!-) based taxonomy (Coeur d'acier et al, 2007;Mitchell, 2008;Žurovcová et al, 2010;Tan et al, 2010).…”