Article Dans Une Revue Philosophical Transactions of the Royal Society B: Biological Sciences Année : 2008

New Caledonia: a very old Darwinian island?

Résumé

New Caledonia has generally been considered a continental island, the biota of which largely dates back to Gondwanan times owing to its geological origin and the presence of phylogenetic relicts. This view is contradicted by geological evidence indicating long Palaeocene and Eocene submersions and by recent biogeographic and phylogenetic studies, with molecular or geophysical dating placing the biota no older than the Oligocene. Phylogenetic relicts do not provide conclusive information in this respect, as their presence cannot be explained by simple hypotheses but requires assumption of many ad hoc extinction events. The implication of this new scenario is that all the New Caledonian biota colonized the island since 37 Ma Local richness can be explained by local radiation and adaptation after colonization but also by many dispersal events, often repeated within the same groups of organisms. Local microendemism is another remarkable feature of the biota. It seems to be related to recent speciation mediated by climate, orography, soil type and perhaps unbalanced biotic interactions created by colonization disharmonies. New Caledonia must be considered as a very old Darwinian island, a concept that offers many more fascinating opportunities of study.

Dates et versions

hal-04915980 , version 1 (28-01-2025)

Identifiants

Citer

Philippe Grandcolas, Jérôme Murienne, Tony Robillard, Laure Desutter-Grandcolas, Hervé Jourdan, et al.. New Caledonia: a very old Darwinian island?. Philosophical Transactions of the Royal Society B: Biological Sciences, 2008, 363 (1508), pp.3309-3317. ⟨10.1098/rstb.2008.0122⟩. ⟨hal-04915980⟩
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