Editor: Solomon Dobrowski
Life on a tropical planet: niche conservatism and the global diversity gradient
Article first published online: 1 NOV 2012
© 2012 Blackwell Publishing Ltd
Global Ecology and Biogeography
Special Issue: Long-term perspectives in macroecology: keys to the past and future of biodiversity. Guest Editors: Jeremy Kerr and Solomon Dobrowski
Volume 22, Issue 3, pages 344–350, March 2013
How to Cite
Romdal, T. S., Araújo, M. B. and Rahbek, C. (2013), Life on a tropical planet: niche conservatism and the global diversity gradient. Global Ecology and Biogeography, 22: 344–350. doi: 10.1111/j.1466-8238.2012.00786.x
- Issue published online: 17 FEB 2013
- Article first published online: 1 NOV 2012
- Danish National Science Foundation. Grant Number: J. no. 21-03-0221
- EC FP6 ECOCHANGE project. Grant Number: GOCE-CT-13 2006–036866
- Clade radiation patterns;
- fossil record;
- latitudinal diversity gradient;
- niche Conservatism;
The niche conservatism hypothesis proposes that species distribution patterns are, by and large, governed by ancestral climatic affinities. Here, we test this hypothesis by combining information on current diversity gradients among lineages, lineage initiation dates, and palaeoclimatic reconstructions.
We test the niche conservatism hypothesis by comparing slopes of latitudinal diversity gradients among terrestrial and aquatic lineages derived from 343 studies from around the world. The prediction is that clades originating during warm periods should be very species rich in tropical regions, exhibiting a steeper richness gradient from lower to higher latitudes than clades originating during cold periods, which are expected to exhibit shallower latitudinal species richness gradients.
Latitudinal gradients for clades that originated in warm climates are steeper and with a strong tropical affinity, whereas organisms originating in colder periods exhibit a shallower diversity gradient or no tropical affinity.
For a broad variety of plants and animals of both marine and terrestrial realms our results are consistent with the idea that higher diversities have arisen among tropical clades because the earth has been predominantly tropical throughout most of its history. Most clades radiated in tropical climates, with subsequent climate changes causing a retraction in distributions. Our study implies that global climate change by itself, even when developing over tens of millions of years, could have shaped the large-scale patterns of diversity prevailing on earth today.