PROGRESS TOWARD A GENERAL SPECIES CONCEPT
Article first published online: 15 FEB 2011
© 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.
Volume 65, Issue 4, pages 923–931, April 2011
How to Cite
Hausdorf, B. (2011), PROGRESS TOWARD A GENERAL SPECIES CONCEPT. Evolution, 65: 923–931. doi: 10.1111/j.1558-5646.2011.01231.x
- Issue published online: 4 APR 2011
- Article first published online: 15 FEB 2011
- Received September 15, 2010, Accepted January 3, 2011
New insights in the speciation process and the nature of “species” that accumulated in the past decade demand adjustments of the species concept. The standing of some of the most broadly accepted or most innovative species concepts in the light of the growing evidence that reproductive barriers are semipermeable to gene flow, that species can differentiate despite ongoing interbreeding, that a single species can originate polyphyletically by parallel evolution, and that uniparental organisms are organised in units that resemble species of biparental organisms is discussed. As a synthesis of ideas in existing concepts and the new insights, a generalization of the genic concept is proposed that defines species as groups of individuals that are reciprocally characterized by features that would have negative fitness effects in other groups and that cannot be regularly exchanged between groups upon contact. The benefits of this differential fitness species concept are that it classifies groups that keep differentiated and keep on differentiating despite interbreeding as species, that it is not restricted to specific mutations or mechanisms causing speciation, and that it can be applied to the whole spectrum of organisms from uni- to biparentals.