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Developing an evolutionary framework for understanding species co-existence: importance of intraspecific genetic variaiton for community ecology

Final Report Summary - COMGEN (Developing an evolutionary framework for understanding species co-existence: importance of intraspecific genetic variaiton for community ecology)

1. Executive summary

The project had two main objectives, to provide the fellow with a new set of theoretical skills and to promote the Thymus system as a model for community genetic studies. The fellow attended a course at the university on modeling in biology and the remaining of the training was by "hands on" under supervision of the scientist in charge. The theoretical skill of fellow was improved during the project period . She obtained experience in using the software Matematica (Wolfram) and build together with supervisors a likelihood model which analyse obtained experimental data that specifically address the topic of the project (importance of intraspecific genetic variation for species co-existence). Further exploration of this model was also obtained by a monte carlo markow chain approach. Both likelihood approach and MCMC add skill to the fellow.
In addition, a significant amount of time was devoted to obtain empirical data on both the species co-existense in thyme communities and maintenance of the genetic polymorphism for chemotype variation in thyme which is relevant for species richness and diversity. A transcriptome study was launched to obtain data on the genetics behind the chemical variation. The obtained data will be used in future collaboration with the host lab on building a landscape genetic model to understand the processes involved in maintaining the chemical variation in thyme.
The work performed has so far resulted in one peer reviewed publication, and two in progress. The work also involved collaboration with other groups inside the host institution. Besides the host lab (Ecological and Evolutionary genetics), work was carried out in the chemical lab (gas chromatograhy to obtain chemical composition of aromatic plants), and at the University of Montpellier (ISEM).
In summary, regarding the main objectives of the study, the fellow obtained theoretical skills by hands on training on a models in community genetics. At least two peer reviewed papers are expected to come out of the project which combine experimental and theoretical work that will aid the establishment of the Thymus system as a model system for community genetics. The collaboration with host lab, and other labs in the host institution, are planned to extend beyond the project period and further funding for doing so are currently being pursued.

2. Summary description of project context and objectives

Project context and objectives:
The research project had two main objectives: to advance the field of community genetics, and to provide the beneficiary with a new set of theoretical skills
Scientific context: Understanding how species compete or facilitate each other's presence and how these interactions vary across environments are at the essence of understanding species co-existence and biodiversity. The nature of interactions is not frozen but can evolve over time . “Community Genetics” is an emerging discipline that aims to integrate evolutionary biology and population genetics with community ecology. Considering genetic variation in studies of several interacting species allows us to understand the genetic and evolutionary basis of community processes. This approach has the potential to make scientific break-troughs in understanding species interactions and their ecological and evolutionary consequences.
So far, European model systems who can address these questions are scarce and the project had as a goal to establish the Thymus system as an empirical model for studying community genetics.
Career development of fellow: By "hands on" experience the project had as objective to provide the beneficiary with a new set of theoretical skill. The fellow obtained experience in using the software Matematica (Wolfram) and build together with supervisors a likelihood model to analyze obtained experimental data that specifically address the topic of the project (importance of intraspecific genetic variation for species co-existence). Further exploration of this model was also obtained by a Monte Carlo Markow Chain approach. Both approaches added new skill to the fellow

3. Description of the main S&T results

Main scientific results:
Working on data obtained on plant species composition in thyme communities the fellow published during the project period a research paper (An allelopathic plant facilitates plant species richness, Journal of Ecology) showing how plant species richness was affected by thyme and that this effect varied with the intra-specific variation for chemical compounds produced by thyme.
A larger co-existence experiment was performed during the project which showed how closely related competing species may co-exist in the presence of thyme. A likelihood model was developed in collaboration with supervisors to disentangle the processes behind these observations. Data obtained from this experiment are currently being analysed using this model.
Beneficiary also engaged in a collaboration with a PhD student from the host lab. Using available data on species co-existence in thyme communities, a species specific facilitation model was developed allowing to group species with respect to their co-existence pattern with thyme. This is currently work in progress.
During the project period, detailed information on the climatic variation among different thyme communities was obtained using data loggers. The chemical compound production in thyme along a natural gradient in chemical variation in the study region was obtained from mother plants and their offspring. Chemical compound production in these plants were obtained via gas chromatography at the host institution. Transcriptomic data of the different chemical types, are currently made available via a collaboration with INRA and U. Montpellier. All these data will be combined and used to build a landscape genetic model aiming at quantifying the selection operating on the Thymus system to understand how this variation is maintained. The chemical polymorphism in Thyme is important for both species co-existence and composition, and it is therefore important to understand what maintains this chemical variation.

Potential impact: The work performed during the project show that the Thymus system is a suitable model system to study to how intra specific variation in dominant species can affect species co-existence and biodiversity. The publication that will come out of this project will aid in establishing this system as a European model for studying community genetics.