title: Climate and soil type together explain the distribution of microendemic species in a biodiversity hotspot.
abstract: The grasshopper genus Caledonula, endemic to New Caledonia, was studied to understand the evolution of species distributions in relation to climate and soil types. Based on a comprehensive sampling of 80 locations throughout the island, the genus was represented by five species, four of which are new to science, of which three are described here. All the species have limited distributions in New Caledonia. Bioclimatic niche modelling shows that all the species were found in association with a wet climate and reduced seasonality, explaining their restriction to the southern half of the island. The results suggest that the genus was ancestrally constrained by seasonality. A molecular phylogeny was reconstructed using two mitochondrial and two nuclear markers. The partially resolved tree showed monophyly of the species found on metalliferous soils, and molecular dating indicated a rather recent origin for the genus. Adaptation to metalliferous soils is suggested by both morphological changes and radiation on these soils. The genus Caledonula is therefore a good model to understand the origin of microendemism in the context of recent and mixed influences of climate and soil type.
authors.affiliation: Muséum national d'Histoire naturelle, Département Systématique et Evolution, Paris, France ; Laboratoire Evolution, Génomes et Spéciation, UPR 9034 CNRS, Gif sur Yvette, France and Université Paris Diderot, Sorbonne Paris Cité, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Nattier
authors.affiliation: Muséum national d'Histoire naturelle, Département Systématique et Evolution, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Grandcolas
authors.affiliation: Muséum national d'Histoire naturelle, Département Systématique et Evolution, Paris, France.
authors.forename: Roseli
authors.initials: R
authors.lastname: Pellens
authors.affiliation: Institut Méditerranéen de Biodiversité et d'Ecologie terrestre et marine, Aix-Marseille Université/CNRS/IRD/UAPV, UMR 237 IRD, Centre IRD de Nouméa, Nouméa, Nouvelle-Calédonie.
authors.forename: Hervé
authors.initials: H
authors.lastname: Jourdan
authors.affiliation: Genoscope, Centre national de Séquençage, Evry, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Couloux
authors.affiliation: Muséum national d'Histoire naturelle, Département Systématique et Evolution, Paris, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Poulain
authors.affiliation: Muséum national d'Histoire naturelle, Département Systématique et Evolution, Paris, France.
authors.forename: Tony
authors.initials: T
authors.lastname: Robillard
mesh_terms: D000818:Animals; D044822:Biodiversity; D002980:Climate; D006110:Grasshoppers; D009510:New Caledonia; D010802:Phylogeny; D012621:Seasons; D012987:Soil; D012988:Soil Microbiology
chemical_list: D012987:Soil