Genetic Variability Under the Seedbank Coalescent

Area of Science:

• Population Genetics
• Evolutionary Biology
• Theoretical Ecology

Background:

• Understanding genetic variability in populations with dormant stages is crucial for evolutionary studies.
• Previous models have not fully captured the impact of large seedbanks on population genetics.

Purpose of the Study:

• To introduce and analyze a novel coalescent framework, the seedbank coalescent, for populations with large seedbanks.
• To investigate how seedbanks influence genetic diversity, time to the most recent common ancestor, and site-frequency spectrum.
• To provide a method for detecting the presence of seedbanks in natural populations from genetic data.

Main Methods:

• Developed a new coalescent structure, the seedbank coalescent, modeling dormant and active lineages.
• Utilized a Wright-Fisher model with seedbank component and mutation to illustrate the coalescent.
• Derived recursions for key population genetic statistics (e.g., time to most recent common ancestor, number of segregating sites).
• Conducted simulations to compare genetic distance statistics and analyze the site-frequency spectrum with and without a seedbank.

Main Results:

• The seedbank coalescent accurately describes genealogies of populations with large seedbanks.
• Dormant lineages qualitatively alter genetic diversity patterns and time to the most recent common ancestor.
• Simulations show significant changes in distance statistics and site-frequency spectrum due to seedbanks.
• Genetic data can be used to detect the presence of large seedbanks.

Conclusions:

• The seedbank coalescent provides a powerful tool for studying populations with dormancy.
• Large seedbanks have a detectable impact on population genetic structure.
• This framework enables empirical detection of seedbank effects in natural populations.