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!
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences