Abstract
Past global change may have forced animal-dispersed plants with megafaunal fruits to adapt or go extinct, but these processes have remained unexplored at broad spatio-temporal scales. Here, we combine phylogenetic, distributional and fruit size data for more than 2500 palm (Arecaceae) species in a time-slice diversification analysis to quantify how extinction and adaptation have changed over deep time. Our results indicate that extinction rates of palms with megafaunal fruits have increased in the New World since the onset of the Quaternary (2.6 million years ago). In contrast, Old World palms show a Quaternary increase in transition rates towards evolving small fruits from megafaunal fruits. We suggest that Quaternary climate oscillations and concurrent habitat fragmentation and defaunation of megafaunal frugivores in the New World have reduced seed dispersal distances and geographical ranges of palms with megafaunal fruits, resulting in their extinction. The increasing adaptation to smaller fruits in the Old World could reflect selection for seed dispersal by ocean-crossing frugivores (e.g. medium-sized birds and bats) to colonize Indo-Pacific islands against a background of Quaternary sea-level fluctuations. Our macro-evolutionary results suggest that megafaunal fruits are increasingly being lost from tropical ecosystems, either due to extinctions or by adapting to smaller fruit sizes.
Original language | English |
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Article number | 20180882 |
Journal | Proceedings of the Royal Society B: Biological Sciences |
Volume | 285 |
Issue number | 1880 |
Early online date | 13 Jun 2018 |
DOIs | |
Publication status | Published - 13 Jun 2018 |
Bibliographical note
This research was funded by the Netherlands Organization for Scientific Research (824.15.007) and the University of Amsterdam (starting grant) to W.D.K., the SNF Early Postdoc.Mobility grant (P2ZHP3_161991) to R.E.O., a grant from the Garfield Weston Foundation to the Global Tree Seed Bank Project at the Royal Botanic Gardens, Kew to W.J.B., the Agence Nationale de la Recherche (ANR-15- CE02-0002-01) to T.L.P.C., and the Carlsberg Foundation Semper Ardens project MegaPast2Future (CF16-0005) and the Villum Investigator project ‘Biodiversity Dynamics in a Changing World’ funded by Villum Fonden (16549) to J.-C.S.Data accessibility
The phylogenetic data and the fruit size data that support the findings of this study are available from the Dryad Digital Repository: http://dx.doi.org/10.5061/dryad.cm4nm. The palm species distribution data are available from the World Checklist of Selected Plant Families (http://apps.kew.org/wcsp). The R script and program to perform the simulations are available from the electronic supplementary material. Additional data files are available from the authors on request.
Keywords
- biodiversity
- extinction
- frugivory
- global change
- megafauna