Species radiation of carabid beetles (broscini: mecodema) in new zealand.
New Zealand biodiversity has often been viewed as Gondwanan in origin and age, but it is increasingly apparent from molecular studies that diversification, and in many cases origination of lineages, postdate the break-up of Gondwanaland. Relatively few studies of New Zealand animal species radiations have as yet been reported, and here we consider the species-rich genus of carabid beetles, Mecodema. Constrained stratigraphic information (emergence of the Chatham Islands) and a substitution rate for Coleoptera were separately used to calibrate Bayesian relaxed molecular clock date estimates for diversification of Mecodema. The inferred timings indicate radiation of these beetles no earlier than the mid-Miocene with most divergences being younger, dating to the Plio-Pleistocene. A shallow age for the radiation along with a complex spatial distribution of these taxa involving many instances of sympatry implicates recent ecological speciation rather than a simplistic allopatric model. This emphasises the youthful and dynamic nature of New Zealand evolution that will be further elucidated with detailed ecological and population genetic analyses.
Department of Morphology, Systematics and Evolutionary Biology, J.F. Blumenbach Institute of Zoology & Anthropology, Georg-August-University Göttingen, Göttingen, Germany.
Julia
J
Goldberg
Department of Anatomy, University of Otago, Dunedin, New Zealand.
Michael
M
Knapp
Department of Ecology, Lincoln University, Canterbury, New Zealand.
Rowan M
RM
Emberson
Independent Researcher, Levin, New Zealand.
J Ian
JI
Townsend
Ecology Group, Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand.
Steven A
SA
Trewick
D000818:Animals; D001499:Bayes Theorem; D001517:Coleoptera / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D049810:Genetic Speciation; D019476:Insect Proteins / Q000235:genetics; D016013:Likelihood Functions; D008957:Models, Genetic; D058889:Molecular Typing; D009520:New Zealand; D010802:Phylogeny; D058974:Phylogeography; D017422:Sequence Analysis, DNA
D004272:DNA, Mitochondrial; D019476:Insect Proteins; D003576:Electron Transport Complex IV