Processes driving the adaptive radiation of a tropical tree ( Diospyros , Ebenaceae) in New Caledonia, a biodiversity hotspot - Université de Montpellier Accéder directement au contenu
Article Dans Une Revue Systematic Biology Année : 2016

Processes driving the adaptive radiation of a tropical tree ( Diospyros , Ebenaceae) in New Caledonia, a biodiversity hotspot

Résumé

Due to its special geological history, the New Caledonian Archipelago is a mosaic of soil types, and in combination with climatic conditions this results in a heterogeneous environment across relatively small distances. A group of over 20 endemic species of Diospyros (Ebenaceae) has rapidly and recently radiated on the archipelago after a single long-distance dispersal event. Most of the Diospyros species in the radiating group are morphologically and ecologically well differentiated, but they exhibit low levels of DNA variability. To investigate the processes that shaped the diversification of this group we employed restriction site associated DNA sequencing (RADseq). Over 8400 filtered SNPs generally confirm species delimitations and produce a well-supported phylogenetic tree. Our analyses document local introgression, but only a limited potential for gene flow over longer distances. The phylogenetic relationships point to an early regional clustering among populations and species, indicating that allopatric speciation with respect to macrohabitat (i.e., climatic conditions) may have had a role in the initial differentiation within the group. A later, more rapid radiation involved divergence with respect to microhabitat (i.e., soil preference). Several sister species in the group show a parallel divergence in edaphic preference. Searches for genomic regions that are systematically differentiated in this replicated phenotypic divergence pointed to loci potentially involved in ion binding and cellular transport. These loci appear meaningful in the context of adaptations to soil types that differ in heavy-metal and mineral content. Identical nucleotide changes affected only two of these loci, indicating that introgression may have played a limited role in their evolution. Our results suggest that both allopatric diversification and (parapatric) ecological divergence shaped successive rounds of speciation in the Diospyros radiation on New Caledonia.
Fichier principal
Vignette du fichier
Munzinger_etal_Syst_Biol_2016_65_2.pdf (973.73 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

hal-01957319 , version 1 (17-12-2018)

Identifiants

Citer

Ovidiu Paun, Barbara Turner, Emiliano Trucchi, Jérôme Munzinger, Mark W Chase, et al.. Processes driving the adaptive radiation of a tropical tree ( Diospyros , Ebenaceae) in New Caledonia, a biodiversity hotspot. Systematic Biology, 2016, 65 (2), pp.212-227. ⟨10.1093/sysbio/syv076⟩. ⟨hal-01957319⟩
109 Consultations
113 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More