Evidence for rapid evolution in a grassland biodiversity experiment

Area of Science:

• Ecology
• Evolutionary Biology
• Genetics

Background:

• Long-term grassland experiments show biodiversity effects on plant productivity increase over time.
• These biodiversity effects persist in new environments, suggesting underlying adaptation.
• Community diversity may act as a selective agent, driving genetic divergence within species.

Purpose of the Study:

• To test the hypothesis that community diversity selects for genetic and epigenetic differences in grassland plants.
• To investigate if selection history (monoculture vs. mixture) influences genetic and epigenetic composition.
• To determine if these changes persist across different environments.

Main Methods:

• Utilized offspring from the Jena Experiment's eleven-year monoculture and mixture plots.
• Grew plants under controlled glasshouse conditions in monocultures and two-species mixtures.
• Employed epiGBS (epigenotyping-by-sequencing) for integrated genetic and DNA methylation analysis.

Main Results:

• Significant genetic and DNA methylation divergence observed in three of five perennial species based on selection history.
• DNA methylation differences largely mirrored genetic divergence.
• Current diversity levels in the glasshouse showed minimal impact on epigenetic variation.

Conclusions:

• Selection for genetic variants, and potentially epigenetic variants, rapidly created distinct monoculture and mixture types within plant species.
• Adaptation to monoculture or mixture environments appears to be driven by selection acting on genetic and epigenetic variation.
• These findings highlight the role of selection in shaping plant populations within diverse or simplified communities.