Origins of old lineages in New Caledonia: A geologically informed test of the island-hopping hypothesis

• Published in: Journal of Biogeography
• Main Authors: Malem, Julien, Robillard, Tony, Cluzel, Dominique, Bellier, Loic, Nattier, Romain, Grandcolas, Philippe, Legendre, Frédéric
• Other Authors: Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Université de la Nouvelle-Calédonie (UNC), Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), European Regional Development Fund; Conseil regional de Guyane; Conseil general de Guyane; Direction de l'Environnement, de l'Amenagement et du Logement; Ministere de l'Education nationale, de l'Enseignement superieur et de la Recherche; Parc amazonien de Guyane; Societe entomologique Antilles-Guyane; ?Our Planet Reviewed' expedition in New Caledonia; MNHN program in partnership; Conservatoire d'espaces naturels de Nouvelle-Caledonie; Province Nord; Office des Postes et Telecommunications; Prince Albert II of Monaco Foundation; Stavros Niarchos Foundation; Total Foundation; Fondation d'entreprise EDF; Fonds Pacifique; Spiecapag; Entrepose Contracting; New-Caledonia Government; Reef Foundation; Belgian National Lottery; COLAS Group; Veolia Water; SYNTHESYS European program; program Action Transversale' of MNHN; program ANR Biodiversite' of the French National Agency for Research
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: BioGeoBEARS; competing hypotheses; historical biogeography; insects; New Caledonia; palaeogeography; palaeoendemics; phylogenetic dating; relicts; stepping stones; vanished islands; [SDU]Sciences of the Universe [physics]; Pacific; New Zealand; Stepping Stones; Antarc*; Antarctica
• Online Access: https://hal.science/hal-04198375; https://hal.science/hal-04198375/document; https://hal.science/hal-04198375/file/Malem-et-al_2023_Journal%20of%20Biogeography%20-%202023%20-%20Malem%20copie.pdf; https://doi.org/10.1111/jbi.14673

International audience Aim: Although New Caledonia (NC) is now considered an oceanic island that emerged ca. 60 Ma, a few terrestrial clades are significantly older, raising the question of the origin of these groups. Classically, old lineages on more recent islands are hypothesized to originate through a process of hopping on now-vanished islands (i.e., island-hopping hypothesis) or other territories. We aim to test this hypothesis by studying a group of cockroaches with several lineages found in NC. Location: New Caledonia, New Zealand, Australia. Taxon: Insects: Blattodea. Methods: We generated a dated phylogeny for blattid cockroaches (Blattidae and Tryonicidae) using Bayesian inference along with fossil calibrations. We reviewed studies on the palaeogeography of the Southwest Pacific region, including hypotheses about the existence of yet-to-be-discovered past islands, and constructed biogeographical tests accordingly. We computed ancestral area estimation under different models in BioGeoBEARS (DEC, BAYAREALIKE, DIVALIKE, with or without +J) to test the role of an island-hopping hypothesis in the establishment of NC blattid fauna. Results: We find divergence times older than 60 Ma for two NC clades. We show that these 'old' endemic lineages can partially be explained by indirect dispersal from Australia or New Zealand through now disappeared islands. Alternative hypotheses suggest multiple independent colonizations of NC from Antarctica or Australia. Main Conclusions: Our results indicate that island-hopping may explain the presence of old groups in NC. The island-hopping hypothesis is nonetheless only supported for a period-area from which geological evidence is ambiguous. Our work highlights both the fruitful interactions between geology and biogeography and the underlying difficulties. The multiple colonization events inferred for NC provide additional insights into the composite nature of NC biota.