FUNCTIONAL GENETIC DIVERGENCE IN HIGH CO2 ADAPTED EMILIANIA HUXLEYI POPULATIONS
Version of Record online: 18 OCT 2012
© 2012 The Author(s). Evolution © 2012 The Society for the Study of Evolution.
Volume 67, Issue 7, pages 1892–1900, July 2013
How to Cite
Lohbeck, K. T., Riebesell, U., Collins, S. and Reusch, T. B. H. (2013), FUNCTIONAL GENETIC DIVERGENCE IN HIGH CO2 ADAPTED EMILIANIA HUXLEYI POPULATIONS. Evolution, 67: 1892–1900. doi: 10.1111/j.1558-5646.2012.01812.x
- Issue online: 1 JUL 2013
- Version of Record online: 18 OCT 2012
- Accepted manuscript online: 27 SEP 2012 10:55AM EST
- Manuscript Accepted: 13 SEP 2012
- Manuscript Received: 30 JUN 2012
- German Federal Ministry of Education and Research
- experimental evolution;
- genetic divergence;
- ocean acidification;
Predicting the impacts of environmental change on marine organisms, food webs, and biogeochemical cycles presently relies almost exclusively on short-term physiological studies, while the possibility of adaptive evolution is often ignored. Here, we assess adaptive evolution in the coccolithophore Emiliania huxleyi, a well-established model species in biological oceanography, in response to ocean acidification. We previously demonstrated that this globally important marine phytoplankton species adapts within 500 generations to elevated CO2. After 750 and 1000 generations, no further fitness increase occurred, and we observed phenotypic convergence between replicate populations. We then exposed adapted populations to two novel environments to investigate whether or not the underlying basis for high CO2-adaptation involves functional genetic divergence, assuming that different novel mutations become apparent via divergent pleiotropic effects. The novel environment “high light” did not reveal such genetic divergence whereas growth in a low-salinity environment revealed strong pleiotropic effects in high CO2 adapted populations, indicating divergent genetic bases for adaptation to high CO2. This suggests that pleiotropy plays an important role in adaptation of natural E. huxleyi populations to ocean acidification. Our study highlights the potential mutual benefits for oceanography and evolutionary biology of using ecologically important marine phytoplankton for microbial evolution experiments.