Ole Seehausen and Gaku Takimoto contributed equally to the work (authorship in alphabetical order).
Speciation reversal and biodiversity dynamics with hybridization in changing environments
Article first published online: 22 NOV 2007
© 2007 The Authors. Journal compilation © 2007 Blackwell Publishing Ltd
Volume 17, Issue 1, pages 30–44, January 2008
How to Cite
SEEHAUSEN, O., TAKIMOTO, G., ROY, D. and JOKELA, J. (2008), Speciation reversal and biodiversity dynamics with hybridization in changing environments. Molecular Ecology, 17: 30–44. doi: 10.1111/j.1365-294X.2007.03529.x
- Issue published online: 22 NOV 2007
- Article first published online: 22 NOV 2007
- Received 23 February 2007; revision accepted 27 July 2007
- hybrid speciation;
- speciation reversal
A considerable fraction of the world's biodiversity is of recent evolutionary origin and has evolved as a by-product of, and is maintained by, divergent adaptation in heterogeneous environments. Conservationists have paid attention to genetic homogenization caused by human-induced translocations (e.g. biological invasions and stocking), and to the importance of environmental heterogeneity for the ecological coexistence of species. However, far less attention has been paid to the consequences of loss of environmental heterogeneity to the genetic coexistence of sympatric species. Our review of empirical observations and our theoretical considerations on the causes and consequences of interspecific hybridization suggest that a loss of environmental heterogeneity causes a loss of biodiversity through increased genetic admixture, effectively reversing speciation. Loss of heterogeneity relaxes divergent selection and removes ecological barriers to gene flow between divergently adapted species, promoting interspecific introgressive hybridization. Since heterogeneity of natural environments is rapidly deteriorating in most biomes, the evolutionary ecology of speciation reversal ought to be fully integrated into conservation biology.