Angiosperm speciation cools down in the tropics. (11th February 2020)

• Record Type: Journal Article
• Authors: Igea, Javier; Tanentzap, Andrew J.
• Editors: Davies, Jonathan
• Is Part Of: Ecology letters. Volume 23:Number 4(2020)
• Page Start: 692
• Page End: 700
• Publication Date: 2020-02-11
• Subjects: angiosperms -- biodiversity -- biogeography -- latitudinal diversity gradient -- macroevolution -- speciation; Ecology -- Periodicals; 577
• DOI: 10.1111/ele.13476
• Languages: English
• ISSNs: 1461-023X

Abstract

Abstract: Recent evidence has questioned whether the Latitudinal Diversity Gradient (LDG), whereby species richness increases towards the Equator, results in higher rates of speciation in the tropics. Allowing for time heterogeneity in speciation rate estimates for over 60, 000 angiosperm species, we found that the LDG does not arise from variation in speciation rates because lineages do not speciate faster in 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, higher species turnover or greater environmental change, may ultimately explain these results. Abstract : 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. Using data for over 60, 000 flowering plant species, we found that the LDG does not arise from variation in speciation rates because lineages do not speciate faster in the tropics. Overall, our results show that speciation rates follow an opposite pattern to global variation in species richness