RT Journal Article
SR Electronic
T1 Angiosperm speciation speeds up near the poles
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 619064
DO 10.1101/619064
A1 J. Igea
A1 A. J. Tanentzap
YR 2019
UL http://biorxiv.org/content/early/2019/04/26/619064.abstract
AB Recent evidence has questioned whether the Latitudinal Diversity Gradient (LDG), whereby species richness increases towards the Equator, results from higher rates of speciation in the tropics. Allowing for time heterogeneity in speciation rate estimates for over 28,000 angiosperm species, we found that the LDG does not arise from variation in speciation rates because lineages speciated faster outside the tropics. These results were consistently retrieved using two other methods to test the association between occupancy of tropical habitats and speciation rates. Our speciation rate estimates were robust to the effects of both undescribed species and missing taxa. Overall, our results show that speciation rates follow an opposite pattern to global variation in species richness. Greater ecological opportunity in the temperate zones, stemming from less saturated communities and greater environmental change, may ultimately explain these results.