Dissertation

Spatial populations with seed-bank

In populations with a seed-bank, individuals can temporarily become dormant and refrain from reproduction until they can become active again. The repository of all dormant individuals in the population is called the seed-bank. Seed-banks are observed in many taxa, including plants, bacteria and other micro-organisms.

Author

Oomen, M.

Date

18 November 2021

Links

Thesis in Leiden Repository

In populations with a seed-bank, individuals can temporarily become dormant and refrain from reproduction until they can become active again. The repository of all dormant individuals in the population is called the seed-bank. Seed-banks are observed in many taxa, including plants, bacteria and other micro-organisms. Typically, they arise as a response to unfavourable environmental conditions. In this thesis we study the effect of a seed-bank on the genetic diversity in a population. The individuals in the population carry one of two gene types, live in colonies and can be either active or dormant. Active individuals can migrate between the colonies, resample and become dormant. Dormant individuals can only become active: they do not migrate and they do not reproduce themselves. The model is described by a system of interacting Fisher-Wright diffusions. Analysing this system of interacting diffusions, we show that the seed-bank enhances the genetic diversity in a population. If the individuals can become dormant for long enough times, the seed-bank can even prevent that a gene type becomes extinct.