Social Evolution


Social Evolution

  Long-term longitudinal field studies | Comparative analyses


We ask Evolutionary and Mechanistic questions about Cooperation, Conflict and Dispersal in Animal Societies,
and their impacts on Life-histories.
We do this through a combination of long-term longitudinal field studies of wild social vertebrates, such as cooperatively breeding sparrow-weavers in the Kalahari desert, and comparative studies across taxa.

Our research on Social Evolution spans two broad themes:


Selection on Cooperation in the Wild

Selection on Cooperation in Variable Environments
Globally, cooperative breeding is associated with highly variable rainfall regimes, suggesting that cooperation may yield particular benefits in such environments. Our long-term field research on sparrow weavers in the Kalahari desert is investigating whether this is the case and why.

Variable environments.jpg

Identifying the Benefits and Costs of Cooperation
Our research combines ecological and molecular approaches to investigating the benefits and costs of cooperation. We have an interest in the roles of Natural and Kin Selection and the interactions between them, and the importance of considering helping in a life-history context and attending to demography.

Origins of Individual Variation in Cooperation

Genes and the Early-Life Environment
We are investigating how genes and the early life environment interact to shape cooperative tendencies in sparrow-weaver societies, using our long-term social and environmental data, our genetic pedigree and genomic tools.

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Trade-offs with other traits
We are investigating the role that trade-offs between cooperation and other tactics may play in generating individual variation and sex differences in cooperative behaviour, and the evolution of alternative life-history trajectories.


Dispersal and Reproductive Strategies

Dispersal Strategies and their Evolutionary Implications
We are investigating dispersal strategies in cooperative societies, and their impacts on population genetic structure, patterns of inbreeding, and the evolution of cooperation and sexually selected traits.


We use automated radio-tracking to study dispersal, and genomics to investigate its impacts on kin structure and inbreeding.

Reproductive Conflict
We are interested in the tactics that dominants employ to monopolise reproduction, and how sexual and kin selection interact to shape the associated traits.

Parental Investment
We are investigating how parents adjust pre- and post-natal investment in offspring according to their environment, and the roles that constraint and adaptation play in such plasticity.

Social Effects on Ageing and Lifespans

COMPETITION and the Evolution of Ageing and Lifespan
We are investigating the impacts of intra-sexual competition on sex differences in ageing, and of reproductive monopolies on rank-related patterns of somatic deterioration in societies.

COOPERATION and the Evolution of Ageing and Lifespan
We are also investigating the impacts of cooperation on key mechanistic pathways implicated in the ageing process. And we are interested more broadly in the impacts of extreme reproductive skews and helping on the evolution of ageing and lifespans in highly cooperative organisms.


Explaining negative kin discrimination in a cooperative mammal society Thompson et al. (2017) PNAS

Sex differences in senescence: the role of intra-sexual competition in early adulthood
Beirne, Delahay & Young (2015) Proc Roy Soc B

The oxidative costs of reproduction are group-size dependent in a wild cooperative breeder
Cram, Blount & Young (2015) Proc Roy Soc B

The origins of consistent individual differences in cooperation in wild banded mongooses

Sanderson et al. (2015) Animal Behaviour

Oxidative status and social dominance in a wild
cooperative breeder
Cram et al. (2015) Functional Ecology

Workforce effects and the evolution of complex sociality in wild Damaraland mole-rats Young et al. (2015) Am Nat

Population genetic structure and direct observations reveal sex-reversed patterns of dispersal in a cooperative bird
Harrison, York & Young (2014) Molecular Ecology

Resolving social conflict among females without overt aggression Cant & Young (2013) Phil Trans Roy Soc B

Intra-sexual selection in cooperative mammals and birds: why aren’t females bigger and better armed?
Young & Bennett (2013) Phil Trans Roy Soc B

Extra-group mating increases inbreeding risk in a cooperatively breeding bird
Harrison, York, Cram & Young (2013) Mol Ecol


MAJOR Model Systems:



This cooperatively breeding bird is our primary model system. We have been continuously monitoring the life-histories of all birds from egg through to senescence in >40 social groups in the Kalahari desert since 2007. We now have >decade of life-history data covering >1700 individuals monitored throughout their lives to date, as well as egg, nestling and cooperative provisioning data from >900 breeding attempts.

Find out more about The Sparrow Weaver Project


Badger 300 (1 of 1).jpg


The UK Animal Plant and Health Agency (APHA) have been monitoring the lives of all individuals in 40 social groups of European badgers for the past 40 years, with a particular focus on their role in bovine tuberculosis dynamics. This work has yielded an incredible longitudinal data set of life-history, morphology, molecular and disease status information on >5000 individuals.

We use this phenomenal model to study the evolution and mechanisms of ageing, and their interactions with sociality and disease, in close collaboration with APHA.

Cooperative mammals, insects and microbes...

We also use a range of other social organisms as models. My PhD and early fellowship work focussed on conflict and cooperation in meerkat societies, and then I set up a longitudinal field study of Damaraland mole-rats. I am now also engaged in collaborative research on cooperation and conflict in banded mongoose and social insect societies, and have recently begun collaborative experimental evolution work on social microbes. We also use published data to conduct comparative studies across social taxa.