Beneficial laggards: multilevel selection, cooperative polymorphism and division of labour in threshold public good games

<p>Abstract</p> <p>Background</p> <p>The origin and stability of cooperation is a hot topic in social and behavioural sciences. A complicated conundrum exists as defectors have an advantage over cooperators, whenever cooperation is costly so consequently, not cooperating pays off. In addition, the discovery that humans and some animal populations, such as lions, are polymorphic, where cooperators and defectors stably live together -- while defectors are not being punished--, is even more puzzling. Here we offer a novel explanation based on a Threshold Public Good Game (PGG) that includes the interaction of individual and group level selection, where individuals can contribute to multiple collective actions, in our model group hunting and group defense.</p> <p>Results</p> <p>Our results show that there are polymorphic equilibria in Threshold PGGs; that multi-level selection does not select for the most cooperators per group but selects those close to the optimum number of cooperators (in terms of the Threshold PGG). In particular for medium cost values division of labour evolves within the group with regard to the two types of cooperative actions (hunting vs. defense). Moreover we show evidence that spatial population structure promotes cooperation in multiple PGGs. We also demonstrate that these results apply for a wide range of non-linear benefit function types.</p> <p>Conclusions</p> <p>We demonstrate that cooperation can be stable in Threshold PGG, even when the proportion of so called free riders is high in the population. A fundamentally new mechanism is proposed how laggards, individuals that have a high tendency to defect during one specific group action can actually contribute to the fitness of the group, by playing part in an optimal resource allocation in Threshold Public Good Games. In general, our results show that acknowledging a multilevel selection process will open up novel explanations for collective actions.</p

Language Evolution

How did language develop and evolve? Here, linguists, cognitive scientists, behavioural ecologists, and theoretical biologists all offer their disparate views on this emerging fiel

One problem, too many solutions: How costly is honest signalling of need?

Our results show that costly signalling theory cannot predict a unique equilibrium cost in signalling games of parent-offspring conflicts if signal cost depends on offspring condition. It follows, contrary to previous claims, that the existence of parent-offspring conflict does not imply costly equilibrium signals

Excavations in the legionary fortress of Brigetio in 2019

In 2019 the excavations in Brigetio focused on the area of the northern gate of the legionary fortress, as the geophysical surveys conducted in the previous year allowed the identification of both the porta praetoria and the via praetoria leading through it. These fieldworks, beside providing new information on the topography of the legionary fortress regarding the porta praetoria and the via praetoria, were also significant from a methodological point of view as they allowed the verification of the results of geophysical surveys conducted in the area earlier, thus contributing greatly to the planning and fine-tuning of future measurements

Short report on the excavations in Brigetio in 2015

In 2015, first time in the history of excavations in Brigetio, the Department of Classical and Roman Archaeology of Eötvös Loránd University and the Klapka György Museum of Komárom carried out excavations in all three major parts of Brigetio: the civil town, the canabae and the legionary fortress.At the site Szőny-Vásártér, the excavation was concentrated on a Roman cellar with collapsed wooden ceiling and a large pit nearby. Most important results are the complete excavation of the cellar, where a large amount of pottery vessels, a Dressel 20 amphora and a bronze cavalry parade helmet came to light. In the territory of the canabae (Szőny-Dunapart) two horrea and another stone building with uncertain function have been found. At the legionary fortress (Szőny-MOL-Kiskertek), the fieldwork was concentrated on the principia and its surroundings

Kooperáció és kommunikáció az állatvilágban: játékelméleti vizsgálatok = Cooperation and communication in biology: game theoretical studies

Pályázatunk elsősorban a kooperáció eredetének számos aspektusát, továbbá a komunikációs rendszerek őszinteségét fenntartó mechanizmusok tanulmányozta. Az elméleti munkák mellett e témakörben humán és állatkísérleteket is elindítottunk. Rámutattunk az olcsó vagy költségmentes kommunikáció őszinteségét fenntartó ökológiai tényezőkre. Megmutattuk például, hogy az emberi kooperáció és az őszinte kommunikáció evolúciója szoros kapcsolatban lehet, illetve állati társadalmakban a kommunikácó őszinteségét a kompetíció erőssége is befolyásolhatja. Vizsgáltuk az ember és a kutya kooperációjának kommunikációs sajátságait. Megmutattuk, hogy a préda-perdátor vagy gazda-parazita kölcsönhatások ismerete szükséges számos kooperatív viselkedés evolúciójának értelmezéséhez. Például a predációs nyomás okozhatja a prédák altruista viselkedését, vagy a kasztrációs parazitát éppen a mutualista társ jelenléte szabályozza. Számos tanulmányban az egyedek térbeli elhelyezkedésének és korlátozott mozgásának a kooperáció evolúciójára kifejtett hatását vizsgáltuk. Több olyan munkánk is született, ahol a humán kommunikáció illetve kooperáció sajátságait a többszintű szelekciós modellek segítségével értelmeztük. Sikerült kiépítsünk egy számítógépes labort, mellyel a jövőben s humán etológiai kísérleteket tudunk végezni. A kutatás legfontosabb eszközének számító evolúciós játékelméletben számos alapkutatás jellegű eredményünk is született, a sztochasztikus elmélet fejlesztésétől a többfajos elméletig. | Our project mainly focused on several aspects of the evolution of cooperation and of the mechanisms maintaining honesty in communicating systems. Beside theoretical works we started animal and human experiments as well. We reveal ecological backgrounds maintaining honesty of cheap or costless communication in numerous systems. It is shown for example that the origin of human cooperation and reliable information processing can be in close connection to each other, and that strength of competition modifies the level of honesty in animal communities. We studied the characteristics of communication in the case of human-dog cooperation. We have shown that characteristics of predator-prey or host-parasite interactions are required to explain evolution of cooperative behaviour in numerous cases. For example, predation load can cause altruistic predator defence among preys, or a mutualistic competitor can control castrating parasites. Several papers focused on the spatial aspects and limited migration of individuals on the evolution of cooperation. Other works emphasized that characteristics of human cooperation can be explained by multilevel selection. We set up a computer lab, which could be a basis of a series of human behavior experiment in the near future. We have significant purely theoretical results in the field of our primary mathematical method, that is of evolutionary game theory; from the development of stochastic theory to the multi-species theory