Phylogeny and Classification of the Trapdoor Spider Genus Myrmekiaphila: An Integrative Approach to Evaluating Taxonomic Hypotheses

Abstract

BackgroundRevised by Bond and Platnick in 2007, the trapdoor spider genus Myrmekiaphila comprises 11 species. Species delimitation and placement within one of three species groups was based on modifications of the male copulatory device. Because a phylogeny of the group was not available these species groups might not represent monophyletic lineages; species definitions likewise were untested hypotheses. The purpose of this study is to reconstruct the phylogeny of Myrmekiaphila species using molecular data to formally test the delimitation of species and species-groups. We seek to refine a set of established systematic hypotheses by integrating across molecular and morphological data sets.Methods and FindingsPhylogenetic analyses comprising Bayesian searches were conducted for a mtDNA matrix composed of contiguous 12S rRNA, tRNA-val, and 16S rRNA genes and a nuclear DNA matrix comprising the glutamyl and prolyl tRNA synthetase gene each consisting of 1348 and 481 bp, respectively. Separate analyses of the mitochondrial and nuclear genome data and a concatenated data set yield M. torreya and M. millerae paraphyletic with respect to M. coreyi and M. howelli and polyphyletic fluviatilis and foliata species groups.ConclusionsDespite the perception that molecular data present a solution to a crisis in taxonomy, studies like this demonstrate the efficacy of an approach that considers data from multiple sources. A DNA barcoding approach during the species discovery process would fail to recognize at least two species (M. coreyi and M. howelli) whereas a combined approach more accurately assesses species diversity and illuminates speciation pattern and process. Concomitantly these data also demonstrate that morphological characters likewise fail in their ability to recover monophyletic species groups and result in an unnatural classification. Optimizations of these characters demonstrate a pattern of “Dollo evolution” wherein a complex character evolves only once but is lost multiple times throughout the group's history.

Phylogenetic structure and species boundaries in the mountain pitviper Ovophis monticola (Serpentes: Viperidae: Crotalinae) in Asia

“…However, despite many efforts to this end, there are few nuclear markers available that provide genetic resolution at low taxonomic levels (Malhotra et al, 2010;Steele et al, 2008;Willows-Munro et al, 2005). Despite the fact that molecular approaches to taxonomy have dominated the literature in recent years, combined analyses of genetic and morphological datasets remain a highly informative (Bailey et al, 2010;Bart et al, 2010;Sanders et al, 2004Sanders et al, , 2006. For these reasons, and because morphological data is available for a large collection of specimens, we determine species boundaries based on morphological analysis in combination with molecular analysis.…”

A toolbox for integrative species delimitation in Machilis jumping bristletails (Microcoryphia: Machilidae)

“…Integrative taxonomy (DeSalle et al, 2005;Padial et al, 2010;Schlick-Steiner et al, 2010) has proven to significantly improve the rigour of species delimitation in various animal taxa (SchlickSteiner et al, 2006;Fontaneto et al, 2007;Bond and Stockman, 2008;Macías-Hernández et al, 2008;Leaché et al, 2009;Bailey et al, 2010;Damm et al, 2010;Glaw et al, 2010;Lumley and Sperling, 2010;Ross et al, 2010;Steiner et al, 2010;Birky et al, 2011;Gurgel-Gonç alves et al, 2011;Moyal et al, 2011;Seppä et al, 2011). Multi-source approaches take advantage of complementarities amongst disciplines: It is assumed that the strength of any species delimitation hypothesis rises with the independence of the information sources , i.e.…”

Phylogenetic reconsideration of Myrmekiaphila systematics with a description of the new trapdoor spider species Myrmekiaphila tigris (Araneae, Mygalomorphae, Cyrtaucheniidae, Euctenizinae) from Auburn, Alabama

“…As discussed by Bailey et al (2010), Myrmekiaphila torreya remains a paraphyletic species with respect to Myrmekiaphila coreyi , and now Myrmekiaphila tigris . Solutions to resolving the conflict between the gene tree and the taxonomy of this species group include recognizing all “basal” lineages as species (speciation by remote control sensu Templeton 1998) or collapsing the entire clade into a single species.…”