Biological Sciences

2019 Strickland Entomology Seminar

At the University of Alberta, Edmonton, on Thursday, March 21, 2019. 
Refreshments at 3:30 pm, Strickland Lecture at 4:00-5:00 pm in CW-410 Biological Sciences Building.

The lecture will be given by: 
Dr. Greg Edgecombe
The Natural History Museum
London, U.K.

Title: Myriapod systematics: the state of play after 20 years of molecular phylogenetics.

Abstract: Myriapods include the centipides, millipedes, pauropods and symphylans. The systematic status of Myriapoda – whether mono-, para- or polyphyletic – and the position of myriapods in the arthropod tree were open questions for over a century. Molecular data decisively answered in favour of monophyly and a sister group relationship to pancrustaceans. With regard to how the four main myriapod groups interrelate, numerous molecular analyses have contradicted a seemingly well-corroborated morphological and developmental hypothesis in which millipedes and pauropods are sister groups, and instead group pauropods with symphylans. Transcriptome-scale datasets suggest that the attraction of pauropods and symphylans (=Edafopoda) is a tree reconstruction artefact, and yield relationships that are congruent with classical morphological hypotheses. Centipede phylogenetics has transitioned from taxonomically well-sampled morphological and multilocus analyses of all major groups, including an injection of new characters from understudied character systems such as the foregut and spiracles, to a growing sample of taxa for which transcriptomes offer vastly larger character sets. Higher-level centipede phylogeny illustrates the trade-off between matrix occupancy and gene number (i.e., the amount of missing data), with morphology serving as a “reality check”. Molecular data have impacted on myriapod systematics at the species-level as well: the longstanding challenge of morphological delimitation of centipede species is complemented by integrative taxonomy using molecular tools, including coalescent approaches to quantitative species delimitation, and molecular dating is increasingly used to test biogeographic hypotheses, including examples of ancient vicariance.