Abstract
Aim
Fruit selection by animal dispersers with different mobility directly impacts plant geographical range size, which, in turn, may impact plant diversification. Here, we examine the interaction between fruit colour, range size and diversification rate in palms by testing two hypotheses: (1) species with fruit colours attractive to birds have larger range sizes due to high dispersal ability and (2) disperser mobility affects whether small or large range size has higher diversification, and intermediate range size is expected to lead to the highest diversification rate regardless of disperser.
Location
Global.
Time Period
Contemporary (or present).
Major Taxa Studied
Palms (Arecaceae).
Methods
Palm species were grouped based on likely animal disperser group for given fruit colours. Range sizes were estimated by constructing alpha convex hull polygons from distribution data. We examined disperser group, range size or an interaction of both as possible drivers of change in diversification rate over time in a likelihood dynamic model (Several Examined State-dependent Speciation and Extinction [SecSSE]). Models were fitted, rate estimates were retrieved and likelihoods were compared to those of appropriate null models.
Results
Species with fruit colours associated with mammal dispersal had larger ranges than those with colours associated with bird dispersal. The best fitting SecSSE models indicated that the examined traits were not the primary driver of the heterogeneity in diversification rates in the model. Extinction rate complexity had a marked impact on model performance and on diversification rates.
Main Conclusions
Two traits related to dispersal mobility, range size and fruit colour, were not identified as the main drivers of diversification in palms. Increased model extinction rate complexity led to better performing models, which indicates that net diversification should be estimated rather than speciation alone. However, increased complexity may lead to incorrect SecSSE model conclusions without careful consideration. Finally, we find palms with more mobile dispersers do not have larger range sizes, meaning other factors are more important determinants of range size.
Fruit selection by animal dispersers with different mobility directly impacts plant geographical range size, which, in turn, may impact plant diversification. Here, we examine the interaction between fruit colour, range size and diversification rate in palms by testing two hypotheses: (1) species with fruit colours attractive to birds have larger range sizes due to high dispersal ability and (2) disperser mobility affects whether small or large range size has higher diversification, and intermediate range size is expected to lead to the highest diversification rate regardless of disperser.
Location
Global.
Time Period
Contemporary (or present).
Major Taxa Studied
Palms (Arecaceae).
Methods
Palm species were grouped based on likely animal disperser group for given fruit colours. Range sizes were estimated by constructing alpha convex hull polygons from distribution data. We examined disperser group, range size or an interaction of both as possible drivers of change in diversification rate over time in a likelihood dynamic model (Several Examined State-dependent Speciation and Extinction [SecSSE]). Models were fitted, rate estimates were retrieved and likelihoods were compared to those of appropriate null models.
Results
Species with fruit colours associated with mammal dispersal had larger ranges than those with colours associated with bird dispersal. The best fitting SecSSE models indicated that the examined traits were not the primary driver of the heterogeneity in diversification rates in the model. Extinction rate complexity had a marked impact on model performance and on diversification rates.
Main Conclusions
Two traits related to dispersal mobility, range size and fruit colour, were not identified as the main drivers of diversification in palms. Increased model extinction rate complexity led to better performing models, which indicates that net diversification should be estimated rather than speciation alone. However, increased complexity may lead to incorrect SecSSE model conclusions without careful consideration. Finally, we find palms with more mobile dispersers do not have larger range sizes, meaning other factors are more important determinants of range size.
| Original language | English |
|---|---|
| Pages (from-to) | 1724-1736 |
| Number of pages | 13 |
| Journal | Journal of Biogeography |
| Volume | 50 |
| Issue number | 10 |
| Early online date | 4 Jul 2023 |
| DOIs | |
| Publication status | Published - Oct 2023 |
Bibliographical note
ACKNOWLEDGEMENTSThis work was supported by the Biodiversity and Ecosystem Services in a Changing Climate Strategic Research Area at the University of Gothenburg. C.C.S. was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil and the São Paulo Research Foundation (FAPESP; 2020-09164-0). S.F. was supported by the Swedish Research Council (2017-03862); C.D.B. and M.F.T.J. were supported by the Swedish Research Council (2017-04980). The computation was enabled by resources provided by the National Academic Infrastructure for Supercomputing in Sweden (NAISS) and the Swedish National Infrastructure for Computing (SNIC) at PDC and HPC2N, respectively, partially funded by the Swedish Research Council through grant agreements no. 2022-06725 and no. 2018-05973. There were no permits required for this work.
Data Availability Statement
The palm fruit colour and geographical occurrence data used for the analyses are publicly available in Kissling et al. (2019) (https://doi.org/10.6084/m9.figshare.9766919) and Global Biodiversity Information Facility (GBIF; ttps://doi.org/10.15468/dl.rjmqfy), respectively. The code for cleaning the data is available on GitHub.(https://github.com/mftorres/palm_leaf/blob/master/notebooks/01_GBIF_variables_data_prep.ipynb)
Keywords
- Arecaceae
- dispersal
- diversification rate
- evolutionary dynamics
- frugivory
- fruit colour
- geographical range size
- macroecology
- palm distribution
- plant traits