Glossary of "Ecology (6th ed.)" by Krebs (2009)
- the evolution of two or more species that interact closely with one another, with each species adapting to changes in the other.
Glossary of "Plant Biology (1st ed.)" by Graham et al. (2003)
- Reciprocal evolutionary influences exerted by two or more organisms on each other.
Glossary of "Evolution (4th ed.)" by Futuyma & Kirkpatrick (2017)
- Strictly, the joint evolution of two (or more) ecologically interacting species, each of which evolves in response to selection imposed by the other. Sometimes used loosely to refer to evolution of one species caused by its interaction with another, or simply to a history of joint divergence of ecologically associated species.
- Graham, L. E., Graham, J. M. & Wilcox, L. W. 2003. Plant Biology. -xxxv + 497 pp. Pearson Education, Inc., Upper Saddle River.
- Krebs, C. J. 2009. Ecology, 6th ed. -xvi + 655 pp. Pearson Benjamin Cummings, San Francisco.
- Futuyma, D. J. & Kirkpatrick, M. 2017. Evolution, 4th ed. -xviii + 602 pp. Sinauer Associates, Inc., Sunderland.