Offspring or survival: Antagonistic effects and the maintenance of genetic variation in an isolated island population of Seychelles warblers (RICHARDSON_UBIO16EE) Offspring or survival: Antagonistic effects and the maintenance of genetic variation in an isolated island population of Seychelles warblers (RICHARDSON_UBIO16EE)

Primary Supervisor: Prof David S Richardson (

Project Description

This project will investigate how different mechanisms - including antagonistic effects on survival and reproduction - interact to maintain genetic variation within a population of the Seychelles warbler.

Genetic variation provides the building blocks for evolution and underpins biodiversity. It is key to the adaptive potential of populations, affecting their probability of extinction. How genetic variation is maintained in natural populations, especially small ones, is therefore a fundamental question in evolutionary and conservation biology. Nowhere is diversity more important than at immune genes, which underpin the ability of individuals and populations to combat pathogens. However we still do not understand how different mechanisms interact to maintain such diversity within natural populations. Only by using modern molecular tools in conjunction with detailed information on individual fitness within populations will we resolve these issues.

Our long-term study of an island population of Seychelles warblers provides an excellent system in which to do this. We have shown that major histocompatibility complex (MHC) variation has been maintained in this bottlenecked species through a combination of natural and sexual selection.Moreover, a single MHC allele can provide individuals with a five-fold greater life expectancy but, intriguingly, the frequency of this allele in the population has not increased. These contradictory results suggest the presence of antagonist effects that counterbalance the positive effect of this allele on survival by negative effects on reproduction.

Now we need a researcher to test the interacting effects of MHC variation on survival and reproduction, and the role of pathogens, using the amazing dataset available for the Seychelles warbler.

This interdisciplinary project will develop an exceptional range of skills in the successful candidate including fieldwork techniques, molecular tools, bioinformatics and analytical expertise. 


i) Spurgin LG, & Richardson DS. (2010). How pathogens drive genetic diversity: MHC, mechanisms and misunderstandings. PRS B 277(1684),979-988.

ii) Richardson DS, et al (2005) MHC-based patterns of social and extra-pair mate choice in the Seychelles warbler. PRS B. 272(1564):759-767

iii) Brouwer L & Richardson DS (2010). MHC‐dependent survival in a wild population: Mol. Ecol, 19(16),3444-3455.

iv) Wright (2014) Evolutionary and conservation genetics of the Seychelles warbler. Thesis dissertation, UEA.

Deadline: 23:59 on Wednesday 6 January 2016

Start date: October 2016
Programme: PhD
Mode of Study: Full Time
Entry Requirements: Acceptable First Degree: Biology or Ecology
Minimum Entry: Standard: 2:1

For further information and to apply, please visit our website: