Mechanisms, development, function and evolution of individual variation in groups

Lead Research Organisation: University of Bristol
Department Name: Biological Sciences

Abstract

In this project I will generate a body of evidence-based theory about individual variation in group-living animals. Group-living animals are extremely important to the functioning of the world's ecosystems, but a crucial aspect of groups - that individuals are very variable in behaviour and appearance - has not been thoroughly studied. The natural world abounds with animals associating in groups, which can be as transient as flocks of birds, as persistent as the perennial colonies of ants, or somewhere in between, such as teams of people in engaged in business enterprise. The behaviour of individuals cooperating in groups combines in complex ways to form the collective behaviour of the group. Evidence is accumulating that, even when individual group members superficially appear similar, such as in honeybees, they are in fact highly variable. For example, honeybees vary in their readiness to perform different tasks. It is clear that such variation must be useful, otherwise natural selection should have eliminated it. Our current understanding of consistent individual differences in behaviour ("personality") is based on models of unrelated individuals competing over resources. In fact, personality in humans and other animals often develops whilst they grow-up in groups. The first part of this project will involve the construction of mathematical models that will help us to understand how personality develops in group-living animals, whether through individual differences in body morphology or in the development of behaviour. I will test these models by examining published data on the development of individual variation in groups of juvenile animals such as tadpoles, caterpillars and birds. In the second part of the project I will identify how ecological factors influence the extent of specialisation. Variation enables some individuals to be specialists at particular tasks, either because they develop the specialised morphology (e.g. the jaws of soldier ants) or become highly skilled in that task (e.g. the flower handling of foraging bees). However, too much specialisation reduces group flexibility, in which case, if conditions change, the group may perform certain tasks poorly. I will construct models to make predictions about how individual variation should be affected by factors such as task number, environmental changeability, group size, and relatedness amongst group members. This body of work will unite currently separate studies of persistent groups of related individuals (e.g. army ants) on the one hand and transient groups of unrelated individuals (e.g. foraging fish) on the other. I will test these models using data on variation among workers of social bees, ants and wasps. I concentrate on this group because of their importance in the world's ecosystems and their highly sophisticated collective behaviour. Next, I will construct some more specific models of certain types of variation in social insect workers, in body size, learning, and how they collect food. These models will enable some very clear predictions that can be easily tested. I will then synthesize my work on animal groups with the extensive literature on the development of personality in children and variation among human groups in businesses. This will help us understand both how the development of personality is affected by group membership such as school classes, and how the mixture of personalities influences the effectiveness of group performance in business. Thus my work will have implications for how society cares for children and how businesses should manage their employees to increase effectiveness, as well as inspiring the future study of personality in humans and other animals.

Planned Impact

The possible beneficiaries of this fundamental research in to animal development and behaviour include workers in a great number of applied ecology areas, including conservation (Natural England and other conservation bodies), crop protection (farmers, pesticide manufactures), and apiculture (beekeepers, bee breeders), all of which benefit from an understanding of animal behaviour and the resulting interactions among species.

For example, my work will provide a greater understanding of how social pollinators gather resources and so will have implications for the conservation of both pollinators and plants, allowing conservation bodies to design appropriate mitigation strategies. My existing link with the Avon Wildlife Trust and Urban Pollinator Project will give me a means by which to ensure these implications are disseminated.

Theory on the development of individual differences has implications for our understanding of how personality traits develop in humans as a function of the groups (i.e. family, school classes) they live in. Some personality traits (e.g. neuroticism) are associated with some serious medical problems. Therefore the work will inform social workers and related professionals, as well as all parents, about the influence of family dynamics on adult personality and some personality disorders. This may ultimately help to reduce health care costs. In the general public, all parents could benefit from the insights about child development. I will ensure impact by a workshop, website, and publications in appropriate lay periodicals.
Greater understanding of the development and effects of human personality could help to understand responsiveness of individuals to shared resource use. For example, conscientiousness and openness to new ideas may influence rates of recycling and responses to the efforts of public bodies to reduce the incidence of behaviours that contribute to climate change.

The insights on the development of personality have implications for the welfare of animals in captivity (zoos, scientists, equine stables), especially for captive breeding programs where the early experience of the offspring may influence their personality and subsequent propensity to breed. My contacts with Bristol Zoo will act as the first point of dissemination.

My results will inform companies and other joint enterprise in the optimal design of groups of personalities that balances performance against flexibility, with obvious benefits for the tax returns of the UK government. These same concepts can be applied in the field of robotics, where steps are being made to perform tasks by groups of similar robots rather than single large ones, such as in the exploration of the oceans and of extra-Earth bodies such as the Moon and Mars. The optimal design of 'swarms' of exploring robots may involve some level of individual variation.

All these benefits could be relevant to policy-makers who clearly influence the work of the practitioners above.

Publications

10 25 50

publication icon
Higginson AD (2016) An adaptive response to uncertainty can lead to weight gain during dieting attempts. in Evolution, medicine, and public health

publication icon
Olivier L (2023) Tests of reproductive skew theory: a review and prospectus in Evolutionary Ecology

publication icon
Ito K (2017) The evolution of cooperation by negotiation in a noisy world. in Journal of evolutionary biology

publication icon
Kennedy P (2018) Altruism in a volatile world. in Nature

publication icon
Kennedy P (2021) Diminishing returns drive altruists to help extended family. in Nature ecology & evolution

publication icon
Higginson A (2016) Comment on 'Are physicists afraid of mathematics?' in New Journal of Physics

publication icon
Higginson AD (2016) Fatness and fitness: exposing the logic of evolutionary explanations for obesity. in Proceedings. Biological sciences

publication icon
Higginson AD (2015) Florivory as an Opportunity Benefit of Aposematism. in The American naturalist

publication icon
Higginson AD (2017) Towards a behavioural ecology of obesity. in The Behavioral and brain sciences