A theoretical study led by the University of Exeter has shed new light on the conditions that lead to the evolution of spite or altruism in structured populations.
Understanding the way in which social behaviours such as altruism – when animals benefit others at their own expense – develop is a long-standing problem that has generated thousands of articles and heated debates.
A subordinate female meerkat babysits her mother's young; an iconic example of cooperative behavior in mammals.
Credit: Andy Young -- wildimages.org
Dr Florence Débarre of Biosciences at the University of Exeter led a study, published today in Nature Communications, which presents a comprehensive framework that applies to a large class of population structures and identifies the crucial elements which support the evolution of social behaviour.
Structured populations are those exhibiting either spatial or social structure. This can range from animals living in social groups - like meerkats - to bacteria in biofilms.
In these populations altruism evolves if, for individuals, the social benefit of living next to others outweighs the costs of competing against them.
Traditionally, population modellers have assumed that the direct benefits and costs of social interactions affect the ability to produce offspring (the fecundity). In natural populations, however, social interactions may also affect survival.
Dr Débarre and her collaborators combined these two features in their model, which revealed new insights. It turns out that helping your neighbours reproduce more or helping them live for longer does not have the same indirect consequences on your own fitness. These indirect consequences are crucial, and determine which type of social behaviour (helping, harming or doing nothing) can evolve.
When competition is fierce because space is so limited that an individual can only reproduce after some space has been freed up by the death of a neighbour, the researcher's results show that the social behaviours that are most advantageous are the ones in which individuals make their neighbours die sooner but at the same time help them reproduce. In other terms, the interaction is spiteful when it comes to survival, but altruistic on fecundity.
Dr Débarre, who is based at the University of Exeter's Penryn Campus in Cornwall, said: "In structured populations, social behaviour evolves if, for social individuals, the net social benefit of living next to other social individuals outweighs the costs of competing against them. We show that the latter depends on the way the population is updated, the type of social game that is played, and on how social interactions affect individual fertility and survival.
"There are ongoing and sometimes very heated debates on which mechanisms favour the evolution of social behaviour. Our mathematical framework also aims at reconciling these different approaches, and shows that they mainly correspond to different viewpoints of the same questions, depending on if we want to give explanations in terms of who is giving benefits to others, or who is receiving benefits."
The article, 'Social evolution in structured populations', by F. Débarre, C. Hauert & M.Doebeli, is published in the latest edition of Nature Communications.
Eleanor Gaskarth | EurekAlert!
Drought hits rivers first and more strongly than agriculture
06.09.2018 | Max-Planck-Institut für Biogeochemie
Landslides triggered by human activity on the rise
23.08.2018 | European Geosciences Union
Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles
Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...
When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.
We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...
Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...
Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...
New measurement method allows researchers to precisely follow the movement of individual molecules over long periods of time
The function of proteins – the molecular tools of the cell – is governed by the interplay of their structure and dynamics. Advances in electron microscopy have...
02.10.2018 | Event News
01.10.2018 | Event News
21.09.2018 | Event News
15.10.2018 | Physics and Astronomy
15.10.2018 | Life Sciences
15.10.2018 | Life Sciences