Abstract:
A systematic classification of Namib Desert darkling beetles (Coleoptera: Tenebrionidae)
based on morphological characters is complicated as strong selection pressures exerted by
desert conditions have led to a suite of convergent morphological characteristics. Here we
present a first and preliminary insight into the relationships within the tribes Zophosini,
Eurychorini and Adesmiini using molecular methods. We analysed partial sequences of the
mitochondrial genes cytochrome oxidase II and cytochrome b of 16 individuals comprising
12 species. Minimum Evolution, Maximum Parsimony, Maximum Likelihood and Bayesian
inference were applied for analysing sequence data. The genus Pimelia was used as outgroup
and for calibrating divergence time estimates. Overall, results supported phylogenies constructed
on morphological characters. The proposed monophyly of the artificially defined tribe
Zophosini did receive sufficient support. Speciation events in Namibian darkling beetles likely
occurred during periods of aridification about 35 Mya, 16 Mya and 5–10 Mya. Those periods
could be related to geological events and climate change due to the glaciation of Antarctica and
the development of the Benguela current.
