cooperation; genetic-transmission; cultural-transmission; individual-learning; humans; co-evolution; social behavior; altruism; genetic transmission; cultural transmission; evolutionary transition
Dridi S., Lehmann L. (2014), On learning dynamics underlying the evolution of learning rules, in Theoretical Population Biology
, 91, 20-36.
Lehmann L., Wakano J. Y., Aoki K. (2013), On optimal learning schedules and the marginal value of cumulative cultural evolution, in Evolution
, 67, 1435-1445.
Van Cleve J., Lehmann L. (2013), Stochastic stability and the evolution of coordination in spatially structured populations., in Theoretical Population Biology
, 89, 75-87.
Powers S., Lehmann L. (2013), The co-evolution of social institutions, demography, and large-scale human cooperation, in Ecology Letters
, 16, 20-36.
Lehmann L., Wakano J. (2013), The handaxe and the microscope: individual and social learning in a multidimensional model of adaptation, in Evolution and Human Behavior
, 34, 119-117.
Mc Ginty S., Lehmann L., Brown S., Rankin D. J. (2013), The interplay between relatedness and horizontal gene transfer drives the evolution of plasmid-carried public good, in Proceedings of the Royal Society B Biological
, 280, 206-221.
Aoki K., Wakano J., Lehmann L. (2012), Evolutionarily stable learning schedules and cumulative culture in discrete generation models, in Theoretical Population Biology
Wakano J., Lehmann L. (2012), Evolutionary and convergence stability for continuous phenotypes in finite populations derived from two-allele models, in Journal of Theoretical Biology
Balloux F., Lehmann L. (2012), Substitution rates at neutral genes depend on population size under fluctuating demography and overlapping generations, in Evolution
Lehmann L. (2012), The demographic benefits of belligerence and bravery in the island model of warfare: defeated group repopulation or victorious group size expansion?, in Plos One
, 6, 1-13.
Lehmann L. (2012), The stationary distribution of a continuously varying strategy in a class-structured population under mutation–selection–drift balance, in Journal of Evolutionary Biology
Lehmann L., Aoki K., Feldman M. (2011), On the number of independent cultural traits carried by individuals and populations, in Philosophical Transactions of the Royal Society of London Series B
Aoki K., Lehmann L., Feldman M. W. (2011), Rates of cultural change and patterns of cultural accumulation in stochastic models of social transmission, in Theoretical Population Biology
, 79(4), 192-202.
Yeaman S., Bshary R., Lehmann L. (2011), The effect of innovation and sex-specific migration on neutral cultural differentiation, in Animal Behaviour
, 82, 101-112.
Lehmann L., Rousset F., Fitness, inclusive fitness, and optimization, in Biology and Philosophy
Pena J., Lehmann L., Noldeke G., Gains from switching and evolutionary stability of multi-player matrix games, in Journal of Theoretical Biology
Yeaman S., Schick A., Lehmann L., Social network architecture and the maintenance of deleterious cultural traits, in Proceedings of the Royal Society Interface
, In press.
Mullon C., Reuter M., Lehmann L., The evolution and consequences of sex-specific reproductive variance, in Genetics
Lehmann L., Rousset F., The evolution of social discounting in hierarchically clustered populations, in Molecular Ecology
, In press.
Lehmann L., Rousset F., The genetical theory of social behaviour, in Philosophical Transactions of the Royal Society of London Series B
Helping behaviors, defined as those behaviors by which an individual in a population increases the fitness of or payoff to other individuals (e.g. cooperation, altruism, mutualism, etc.) are widespread in the natural world, both across taxa and at different levels of biological organization. Among the diversity of helping behaviors, one of the most impressive example occurs in humans. At the heart of human sociality are behaviors and actions in which one individual provides help for another. Understanding the variation in the prevalence and nature of helping behaviors in humans and other species requires identifying all the factors causing their evolution, as well as those determining their expression during the lifetime of an individual. Much theoretical progress has been made in the last forty-five years in identifying the causes responsible for the evolution of helping behaviors. But for mathematical tractability, most models for the evolution of helping so far have assumed a one-locus genetic underpinnings (i.e. individuals are characterized by a single gene), and that the evolving population is of infinite size and not stratified (all individuals are alike but may carry different alleles). However, organisms are characterized by multilocus genotypes and, a helping behavior, like any other trait, is not determined by the genotype alone. The behavior may also be socially learned (culturally transmitted), or individually learned by exploration during the lifetime of an individual, or be the result of a combination of these factors. Furthermore, natural populations are of finite size, which causes random genetic drift to affect the evolutionary trajectory of helping behaviors. Finally, natural populations tend to be stratified, especially human populations.More recently, general mathematical frameworks have been developed, which enables one to study the evolution of behaviors accommodating more realistic and complex assumptions (trait determinism, structure and demographics of populations). These developments now finally put researchers in the position of integrating more realistic feature into their models; allowing them to tackle long-standing and yet unresolved questions in evolutionary biology. How does genetic drift and natural selection interact to determine the evolutionary trajectory of multilocus behaviors? Why do individuals in humans and some other species imitate the helping behaviors of other individuals in the population? Have individuals evolved to learn to behave optimally in social games by trial-and-error, insight or deduction, or are helping behaviors always innate? Why are individuals living in autonomous families, willing to loose some of their autonomy and contribute reproduction enhancing resources to a central authority like a local or a regional leadership, thus favoring the transition from small-scale homogeneous social groups to larger-scale stratified social groups?This research proposes to study the evolution of helping behaviors by trying to find answers to these questions. To this end, we will construct mathematical models into three distinct but complementary directions. First, in order to improve our understanding of the selective pressure on genetically-determined helping behaviors, we will move beyond the usual one-locus assumption and construct a series of multilocus models of social behaviors in geographically-structured populations of finite size. Second, in order to improve our understanding of the interactions between the innate, socially learned and individually learned aspect of helping behaviors, and to improve our understanding of the selective pressure on social and individual learning itself, we will construct a series of gene-culture coevolutionary models of social and individual learning of helping. Third, in order to improve our understanding of the transition from small-scale homogeneous social groups, to larger-scale stratified social groups, we will construct a series of models aiming at clarifying the role played by kinship ties, cultural transmission, and technological factors for the evolution of resource transfer between classes of individuals.The different modeling parts of this research project are an attempt at providing a more unified and complete approach to understand the evolution and expression of helping behaviors. Specifically, this will be carried out by using gene-culture co-evolutionary theory, which has been proposed as the key to the integration of the behavioral sciences.