Biodiversity is known to increase many ecosystem properties, for example aboveground productivity, and this effect has been shown to strengthen over time. The mechanisms underlying this so-called biodiversity effect, however, are still debated. The authors could for the first time establish whether epigenetic or genetic divergence is responsible for the observed biodiversity effects in an experiment with meadow plants. The hypothesis was that plants growing in mixtures develop more beneficial interactions via selection on genetic or epigenetic variation already present in a population, sexual recombination or by new mutations arising over time. Vice versa, plants growing in monoculture would be selected for high performance in the absence of other plant species, for example better defense against specialized pathogens, again via genetic or epigenetic mechanisms. The study could prove that the described adaptations occurred due to genetic divergence at the level of base-pair sequences in DNA molecules in five perennial plant species. In contrast, epigenetic changes, i.e. differences in methylation of bases between DNA molecules, was mostly following the genetic differences and contributed little independent variation for the observed evolutionary change.
The authors thus show that rapid evolution can happen in grasslands dominated by perennial plant species in a very short period of time (here approximately 10 years). Relatively fast evolutionary adaptation based on genetic changes so far was known from bacteria, often after hundreds to thousands of generations. This paper changes existing views on plant community evolution, but more importantly has far-reaching implications for conservation and restoration practices.
Further reading and contact
van Moorsel, S. J., M. W. Schmid, C. A. M. Wagemaker, T. P. van Gurp, B. Schmid, and P. Vergeer. 2019. Evidence for rapid evolution in a grassland biodiversity experiment. Molecular Ecology in press. DOI 10.1111/mec.15191.
Molecular Ecology 28:4097–4117 DOI 10.1111/mec.15191.
Twitter: @sofiavanmoorsel, @BWSchmid