Genetic diversity

The effects of interspecific biodiversity on intraspecific genetic diversity: a community genomics approach

Principle Investigators: Prof. Dr. Holger Schielzeth, Jena; Prof. Dr. Jochen B. W. Wolf, München

Genetic diversity provides the raw material for evolutionary adaptation. The processes that maintain or deplete genetic variation are therefore of central concern in changing environments. Interestingly, inter- and intraspecific genetic diversity often covary positively in natural populations (a phenomenon known as species-genetic diversity correlations SGDC). However, the causes for this covariation are still unknown. One reason for the lack of knowledge is the paucity of long-term experimental studies that manipulate species diversity and thus allow an assessment of feedbacks on genetic diversity. Our project unites population genetics and community ecology in an approach that has become known as community genetics.

We address the following questions: (1) Does plant species diversity influence the maintenance of intraspecific standing genetic variation of plant populations? (2) Does plant species diversity influence the distribution of genetic variation across individuals? (3) Did plant species systematically change in their genetic composition across the 18 years of experimental manipulation of the Jena Experiment? We study intraspecific and inter-individual genetic diversity in a set of 12 focal plant species (three species per functional group) across the full species-diversity gradient of the Jena Experiment using modern genotyping-by-sequencing approaches. We will then replicate and generalize to the full set of 60 species, including samples from the founding population from 2002 (stored as seed material) and species-specific samples taken from contemporary high and low diversity communities. This approach allows us to test for the first time in a field experimental setting how species diversity of the community affects intra-specific genetic.