Updated June 2013


Dr. Adam Hayward

Career Research Interests Collaborations Publications

ERC-funded Post-doctoral Research Associate

Department of Animal and Plant Sciences
University of Sheffield
Western Bank
Sheffield S10 2TN, U.K.
a.hayward@sheffield.ac.uk - twitter: @adhayward18 - more info: http://adhayward.wordpress.com/


2007 – 2011: PhD Evolutionary Ecology, University of Edinburgh

    • Thesis title: “Parasites and Life-History Variation in a Wild Mammal Population”
    • Supervisors Prof. L.E.B. Kruuk, Dr A.J. Wilson, and Prof. J.M. Pemberton.

2003 – 2006: BSc. (Honours) Biology, University of Nottingham

Research interests:

My general research interest is in attempting to understand the causes and consequences of natural variation in life-history traits. I am also interested in studying senescence in life-history traits that occurs in late life, how such traits change with environmental conditions, and how environmental conditions experienced in early life may shape senescence. Finally, I am interested in investigating how the genetic and phenotypic associations between traits vary across ages and heterogeneous environmental conditions.

PhD Research:

My PhD research focused on the relationship between parasite infection and life-history variation in the natural population of Soay sheep on the island of Hirta in the St Kilda archipelago, NW Scotland. The majority of work on host-parasite interactions has been performed on laboratory populations of model organisms, and despite the detailed knowledge these studies have given us, such populations are far from the genetically variable, resource-limited and age-structured human and wildlife populations for which parasites are a concern. During my PhD, I provided the first results consistent with senescence in parasite resistance in a longitudinally-monitored wild population, and that senescence was accelerated in individuals which had experienced more adverse environmental conditions earlier in their lives. In another analysis, I showed that this was reflected in lamb parasite resistance, with lower resistance in lambs born to older mothers. In addition, males born into large litters, and females commencing reproduction earlier in their lives had lower parasite resistance as adults, emphasizing the importance of early life conditions in determining performance, and that such effects can persist into adulthood. I have also investigated the strength of selection on parasite resistance, and found strong selection in lambs but not adults, and changes in the strength of selection on parasite resistance and body weight across varying environmental conditions. I am also finalising work describing age-specific changes in reproductive performance, and providing evidence for varying senescence patterns across five different reproductive traits of females. Recently, I have also been working on associations between measures of immune phenotype, parasite burdens, and host life-history traits, in an extension of previous work with collaborators which was the first longitudinal study of the associations between immune phenotype and fitness in a wild mammal.

Current work:

I hope to continue to do some work on the Soay sheep. With collaborators, I aim to further investigate associations between different parasite species and immune phenotype, and how they influence aspects of host fitness.

During my post-doctoral position, I will be investigating the phenotypic and genetic relationships between human life-history traits and fitness using data collected from pre-industrial populations of Finns. Possible avenues of research include determining the fitness consequences of food availability around the time of birth, and how conditions around the time of birth interact with current conditions to influence survival and reproductive performance. Another potential subject are the changes in genetic variance in life history traits across environmental conditions and across ages, and how these could impact on the evolution of such traits in human populations. Finally, a large longitudinal data set could enable us to study changes in genetic variance and trade-offs across the time series of the data, from the late eighteenth to mid-twentieth century, potentially giving insight into how modernization has impacted on the potential for selection and evolution in recent human history.  


  • Dan Nussey, University of Edinburgh

  • Andrea Graham, Princeton University

  • Georgii Bazykin, Russian Academy of Sciences


Hayward A.D., Rickard IJ & Lummaa V 2013 The influence of early-life nutrition on mortality and reproductive success during a subsequent famine in a pre-industrial population. Proceedings of the National Academy of Sciences of U.S.A. accepted with minor revision.

Hayward, A.D. & Lummaa, V. (2013) Testing the evolutionary basis of the Predictive Adaptive Response hypothesis in a preindustrial human population. Evolution, Medicine and Public Health 106–117. PDF

Hayward, A.D., Wilson, A.J., Pilkington, J.G., Pemberton, J.M. & Kruuk, L.E.B. (2013) Reproductive senescence in female Soay sheep: variation across traits and contributions of individual ageing and selective disappearance. Functional Ecology 27: 184-195. PDF

Brown, E.A., Pilkington, J.G., Nussey, D.H., Watt, K.A., Hayward, A.D., Tucker, R., Graham, A.L., Paterson, S., Beraldi, D., Pemberton, J.M. & Slate, J. (2012) Detecting genes for parasite burden and immunological traits in a wild population: testing the candidate gene approach. Molecular Ecology 22: 757-773. PDF

Hayward, A.D., Holopainen, J., Pettay, J. & Lummaa, V. (2012) Food and fitness: associations between crop yields and life-history traits in a longitudinally-monitored preindustrial human population. Proceedings of the Royal Society of London B 279: 4165-4173. PDF

Hayward, A.D., Wilson, A.J., Pilkington, J.G., Clutton-Brock, T.H., Pemberton, J.M. & Kruuk, L.E.B. 2011 Natural selection on a measure of parasite resistance varies across ages and environmental conditions in a wild mammal. Journal of Evolutionary Biology 24(8): 1664-1676 PDF

Graham, A.L., Hayward, A.D., Watt, K.A., Pilkington, J.G., Pemberton, J.M. & Nussey, D.H. (2010) Fitness correlates of heritable variation in antibody responsiveness in a wild mammal. Science 330, 662-665. PDF

Hayward, A.D., Pilkington, J.G., Pemberton, J.M. & Kruuk, L.E.B. (2010) Maternal effects and early-life performance are associated with parasite resistance across life in free-living Soay sheep. Parasitology 137, 1261-1273. PDF

Hayward, A.D., Wilson, A.J., Pilkington, J.G., Pemberton, J.M. & Kruuk, L.E.B. (2009) Ageing in a variable habitat: environmental stress affects senescence in parasite resistance in St Kilda Soay sheep. Proceedings of the Royal Society of London B- Biological Sciences 276, 3477-3485. PDF
(and press coverage in Metro, The Scotsman, Daily Express, The Sun, BBC Radio Scotland, BBC News Scotland, GMTV Scotland)