April 18, 2017

A new paper led by Camille Pitteloud (University of Lausanne) and co-authored by Tomasz Suchan has been published in the Proceedings of the Royal Society B. It addresses the question whether the niche shift evolution is faster in sympatrically than allopatrically evolving species, applied to a the Palearctic butterflies of genus Pyrgus.

The study presents a rare case when the impact of a spatial context of speciation has been explored for an entire clade. A comparison of evolutionary rates along the climate variables across pairs of sister species revealed that the niche shift is faster when speciation occurs in sympatry rather than in allopatry. It is assumed than in sympatric speciation, ecological divergence is essential as a mechanism to avoid competition when species co-occur. Our results support this hypothesis – although the defined biogeographic areas significantly differed in climate, the niche shift was higher when speciation occurred sympatrically. The study also pointed to the importance of spatial scale in comparative phylogeography – when the biogeographic areas were too broadly defined, the analysis revealed the higher rates of niche shifts in allopatry.

Citation

Pitteloud C, Arrigo N, Suchan T, Mastretta-Yanes A, Vila R, Dincă V, Hernández-Roldán J, Brockmann E, Chittaro Y, Kleckova I, Fumagalli L, Buerki S, Pellissier L, Alvarez N, 2017. Climatic niche evolution is faster in sympatric than allopatric lineages of the butterfly genus Pyrgus. Proceedings of the Royal Society B 285: 20170208 DOI