New Guinea highland origin of a widespread arthropod supertramp

Abstract

The biologically and geologically extremely diverse archipelagos of Wallacea, Australasia and Oceania have long stimulated ecologists and evolutionary biologists. Yet, few molecular phylogenetic analyses of the terrestrial fauna have been carried out to understand the evolutionary patterns. We use dense taxon and character sampling of more than 7000 bp DNA sequence data for a group of diving beetles ranging from the Holarctic throughout Asia to as far east as French Polynesia. We here show that an ecologically diverse, common and widespread (Portugal to New Zealand) arthropod supertramp species originated in the highlands of New Guinea, ca 6.0-2.7 Myr ago. The approximately 25 closely related species are narrow endemics in Australasia/Oceania. The ancestor of this clade colonized that region from Eurasia ca 9-7 Myr ago. Our finding contradicts the widely held view of local endemism as an evolutionary dead end, as we find multiple peripatric speciation events within the Pleistocene and complex colonization patterns between the Oriental and Australian zoogeographic regions, including the recolonization of Eurasia, jumping across Wallace's line and colonization of continental Australia out of New Guinea. Our study strongly highlights the importance of dispersal over water gaps in shaping biogeographic patterns.

Nucleotide substitution rates for the full set of mitochondrial protein-coding genes in Coleoptera

“…A similar rate was also found in other studies comparing more closely related species of Coleoptera and using different combinations of mitochondrial genes, both ribosomal and protein-coding (e.g., Leys et al, 2003;Pons and Vogler, 2005;Pons et al, 2006;Balke et al, 2009;Ribera et al, 2010).…”

The towering orogeny of New Guinea as a trigger for arthropod megadiversity

“…In order to calibrate the topology and since the fossil record is scarce for diving beetles, we used the information of three recent publications on Coleoptera in which a divergence rate for the same cytochrome c oxidase subunit 1 fragment used in this study was calculated, that is on dytiscid beetles 56 (mean rate ¼ 0.0195 substitutions per site per million years per lineage, subs/s/Myr/l), on tenebrionid beetles 57 (mean rate ¼ 0.0177 subs/s/Myr/l) and on carabid beetles 58 (mean rate ¼ 0.0145 subs/s/Myr/l). We set the ucld.mean with a normal distribution encompassing the three mean rates recovered in these studies (0.0145-0.0195 subs/s/Myr/l).…”

Multiple transgressions of Wallace's Line explain diversity of flightlessTrigonopterusweevils on Bali

“…As a result, we were not able to use a secondary calibration for the Trigonopterus radiation. In a first calibration, several substitution rates of Coleoptera have been used (calculated for the COI marker using multiple fossils and geological evidences [31][32][33]-see [34] for a rationale on the use of this interval). The early diversification of Trigonopterus would have taken place more than 60 Ma which appears significantly too old.…”