Evolutionary time drives global tetrapod diversity
journal contribution
posted on 2023-05-20, 02:54authored byMarin, J, Rapacciuolo, G, Costa, GC, Graham, CH, Thomas BrooksThomas Brooks, Young, BE, Radeloff, VC, Behm, JE, Helmus, MR, Hedges, SB
Global variation in species richness is widely recognized, but the explanation for what drives it continues to be debated. Previous efforts have focused on a subset of potential drivers, including evolutionary rate, evolutionary time (maximum clade age of species restricted to a region), dispersal (migration from one region to another), ecological factors and climatic stability. However, no study has evaluated these competing hypotheses simultaneously at a broad spatial scale. Here, we examine their relative contribution in determining the richness of the most comprehensive dataset of tetrapods to our knowledge (84% of the described species), distinguishing between the direct influences of evolutionary rate, evolutionary time and dispersal, and the indirect influences of ecological factors and climatic stability through their effect on direct factors. We found that evolutionary time exerted a primary influence on species richness, with evolutionary rate being of secondary importance. By contrast, dispersal did not significantly affect richness patterns. Ecological and climatic stability factors influenced species richness indirectly by modifying evolutionary time (i.e. persistence time) and rate. Overall, our findings suggest that global heterogeneity in tetrapod richness is explained primarily by the length of time species have had to diversify.
History
Publication title
Proceedings of the Royal Society B: Biological Sciences
Volume
285
Issue
1872
Article number
20172378
Number
20172378
Pagination
1-8
ISSN
0962-8452
Department/School
Institute for Marine and Antarctic Studies
Publisher
Royal Soc London
Place of publication
6 Carlton House Terrace, London, England, Sw1Y 5Ag