Abstract
I propose that global patterns in numbers of range-restricted endemic species are caused by variation in the amplitude of climatic change occurring on time-scales of 10-100 thousand years (Milankovitch oscillations). The smaller the climatic shifts, the more probable it is that palaeoendemics survive and that diverging gene pools persist without going extinct or merging, favouring the evolution of neoendemics. Using the change in mean annual temperature since the last glacial maximum, estimated from global circulation models, I show that the higher the temperature change in an area, the fewer endemic species of mammals, birds, reptiles, amphibians and vascular plants it harbours. This relationship was robust to variation in area (for areas greater than 10(4) km2), latitudinal position, extent of former glaciation and whether or not areas are oceanic islands. Past climatic change was a better predictor of endemism than annual temperature range in all phylads except amphibians, suggesting that Rapoport's rule (i.e. species range sizes increase with latitude) is best explained by the increase in the amplitude of climatic oscillations towards the poles. Globally, endemic-rich areas are predicted to warm less in response to greenhouse-gas emissions, but the predicted warming would cause many habitats to disappear regionally, leading to species extinctions.
Full Text
The Full Text of this article is available as a PDF (434.6 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Cronin T. M. Speciation and stasis in marine ostracoda: climatic modulation of evolution. Science. 1985 Jan 4;227(4682):60–63. doi: 10.1126/science.227.4682.60. [DOI] [PubMed] [Google Scholar]
- Dynesius M., Jansson R. Evolutionary consequences of changes in species' geographical distributions driven by Milankovitch climate oscillations. Proc Natl Acad Sci U S A. 2000 Aug 1;97(16):9115–9120. doi: 10.1073/pnas.97.16.9115. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jetz Walter, Rahbek Carsten. Geographic range size and determinants of avian species richness. Science. 2002 Aug 30;297(5586):1548–1551. doi: 10.1126/science.1072779. [DOI] [PubMed] [Google Scholar]
- Myers N., Mittermeier R. A., Mittermeier C. G., da Fonseca G. A., Kent J. Biodiversity hotspots for conservation priorities. Nature. 2000 Feb 24;403(6772):853–858. doi: 10.1038/35002501. [DOI] [PubMed] [Google Scholar]
- Peltier W. R. Ice age paleotopography. Science. 1994 Jul 8;265(5169):195–201. doi: 10.1126/science.265.5169.195. [DOI] [PubMed] [Google Scholar]
- Pimm S. L., Russell G. J., Gittleman J. L., Brooks T. M. The future of biodiversity. Science. 1995 Jul 21;269(5222):347–350. doi: 10.1126/science.269.5222.347. [DOI] [PubMed] [Google Scholar]
- Templeton A. R. Nested clade analyses of phylogeographic data: testing hypotheses about gene flow and population history. Mol Ecol. 1998 Apr;7(4):381–397. doi: 10.1046/j.1365-294x.1998.00308.x. [DOI] [PubMed] [Google Scholar]