Determinants of genetic diversity: Important Factors For Ecosystem Resilience

Project Information

DIFFER

Grant agreement ID: 891088

DOI

10.3030/891088

Project closed

EC signature date 27 February 2020

Start date 1 October 2020

End date 30 September 2023

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 304 724,16

EU contribution

€ 304 724,16

Coordinated by

UNIVERSITAT BASEL
Switzerland

Periodic Reporting for period 1 - DIFFER (Determinants of genetic diversity: Important Factors For Ecosystem Resilience)

Reporting period: 2020-10-01 to 2023-09-30

Summary of the context and overall objectives of the project

Human activities and the effects of climate change are causing a significant loss of biodiversity, which is having negative impacts on ecosystems. The underlying basis of all biodiversity is genetic diversity – the variation of DNA sequences among individuals. Maintaining genetic diversity is thus crucial for the survival and reproduction of organisms, especially in the face of changing environments. The most direct source of all genetic diversity are germline mutations. However, we don't fully understand how the rate of these mutations varies between different species and how this variation affects genetic diversity. There are other factors at play as well, like the size of a population, natural selection, how genes are reshuffled, an organism's life history, and the size of its genome. All of these factors can influence genetic diversity.
In my research project I thoroughly examined the role of these potential determinants of genetic diversity, with the aim of identifying the main determinants of genetic diversity.
In conclusion, I found correlations of life history traits and the ecological niche with genetic diversity. Importantly, I found highly variable mutation rates that are positively correlated with heterozygosity, indicating their contribution to genetic diversity and species richness. These results help us to better understand how organisms and their mutation rates evolve. It also gives us new insights into how to manage genetic diversity in ecosystems.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

What is the impact of different life history and ecological traits on genetic diversity? To investigate this, I collected life-history and ecological information for 200 species of cichlid fishes (WP1.1) as well as genetic information on diversity, selection, recombination, and demography (WP1.2) and used linear modeling to see how those traits affect genetic diversity (WP3). In analyzing these relationships, body size showed a negative correlation with genetic diversity, supporting higher diversity in smaller, shorter-lived species. The ecological niche also had an impact, with open-water species being more genetically diverse.
What is the relative contribution of the de novo mutation rate to genetic diversity? To answer this question, I raised fish families in aquaria, sequenced their DNA (WP 1.2) and screened their genome to find new mutations (WP2) – changes in the DNA that are present only in the offspring and not in the parents. On average, these fishes have about seven new mutations per generation. This rate can vary quite a bit between different species, with some having rates as much as six times faster than others. Interestingly, species with more mutations belong to taxonomic groups that are also more species rich. However, population size and other factors need to be considered.
Overview of the exploitation and dissemination actions of the project results: 3 peer-reviewed publications, 2 outreach articles, 2 invited talks, 3 conferences attended, 2 workshops attended, 3 dissemination events organized.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The loss of biodiversity has implications for ecosystems and their benefits they provide to us. Yet, high genetic diversity allows species to be resilient over longer terms, providing sustainable ecosystem services and thus have socio-economic impacts. In this project, progress beyond the state of the art towards the use of genomic tools to assess this diversity were made. Genomic analyses can support management actions, but collaborations between scientists and nature manager are important to make this work.

Candidate determinants of genetic diversity