PARENT SESSION
Oral Session # 83: Ecological Theory II: Modeling; Competition.
Presiding: C Brassil
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Meeting Room 201.
Asymmetric competition between relatives.
Aikio, Sami1, 1 University of Helsinki, Helsinki, Finland, Finland
ABSTRACT- Hamilton's rule predicts that individuals attempt to maximize their inclusive fitness. The number of offspring produced by an individual is typically a non-linear function of its gain of a limiting resource. Individual's resource gain depends on the availability of the resource, the number of individuals in the population competing for the resource, and the distribution of the resource among them. I carried out a theoretical analysis, asking whether related individuals should distribute a resource in a different way than a population of unrelated individuals does. I also studied the optimal distribution of a resource from the view-point of different sized individuals and the effects of optimal resource distribution on population dynamics. I found that the individuals which are most efficient in converting the gained resources into offspring production, are predicted to get the largest share of the resource when population consists of related individuals. The optimal resource distribution was rather symmetric in low population densities, but asymmetric in high population densities, which stabilized population dynamics. The results suggest that altruistic resource share can evolve also in viscous populations of equally related individuals, which was earlier considered not to be possible. The difference is due to the assumption of non-linear resource use efficiency in offspring production made in the present study, which contrasts to the earlier assumption of altruistic behaviour and offspring production being directly related to each other.
Key words: Hamilton's rule, kin-selection, population dynamics, optimization