Diversification mechanisms in the Andean grasshopper genus Orotettix (Orthoptera: Acrididae): ecological niches and evolutionary history

SCATOLLINI, M.C.; CONFALONIERI, V.A.; LIRA-NORIEGA, A. ; PIETROKOVSKY, S; CIGLIANO, M. M.

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018 vol. 123 p. 697 - 711

0024-4066

The Andes harbour an outstanding taxonomic and ecological diversity, for which several mechanisms promotingdiversification, including ecological gradients and allopatric speciation, have been cited. The grasshopper genusOrotettix is an informative but challenging group to study diversification mechanisms because species in the genusare morphologically very similar, have low vagility and display local endemism over a complex topography in theCentral Andes. We conducted several tests using ecological niche overlap and predictions of geographical distributionsof Orotettix species on a phylogenetic framework to disentangle their speciation patterns. A multilocus molecularphylogeny was generated for Orotettix. Niche similarity tests were performed and the degree of niche overlap wasestimated between species. Ecological niche models were generated to assess the realized ecological niche and potentialdistribution. The phylogenetic signal between the phylogenetic relatedness and niche overlap, and geographicaland the environmental distances were analysed. Our findings suggest that speciation was not restricted to a singleperiod and that species origins might have coincided with glacial?interglacial cycles of the Pleistocene. Given thatwe only found cases of niche conservatism for Orotettix, we infer that allopatric speciation had the primary role inits diversification. No significant phylogenetic signal was found, probably due to an island-like radiation process.