The balance model of honest sexual signaling
Costly signalling theory is based on the idea that individuals may signal their quality to potential mates and that the signal's costliness plays a crucial role in maintaining information content (‘honesty’) over evolutionary time. Whereas costly signals have traditionally been described as ‘handicaps’, here we present mathematical results that motivate an alternative interpretation. We show that under broad conditions, the multiplicative nature of fitness selects for roughly balanced investments in mating success and viability, thereby generating a positive correlation between signal size and quality. This balancing tendency occurs because selection for increased investment in a fitness co…
Computer code from Sex roles and the evolution of parental care specialization.
Computer code for the mathematical model in Mathematica
Computer code from Sex roles and the evolution of parental care specialization
Computer code for the mathematical model in Mathematica
Model details from Sex roles and the evolution of parental care specialization.
Details of the mathematical model, including the case of shared parentage
Computer code from Sex roles and the evolution of parental care specialization.
Computer code for the mathematical model in Mathematica
Sex roles and the evolution of parental care specialization
Males and females are defined by the relative size of their gametes (anisogamy), but secondary sexual dimorphism in fertilization, parental investment and mating competition is widespread and often remarkably stable over evolutionary timescales. Recent theory has clarified the causal connections between anisogamy and the most prevalent differences between the sexes, but deviations from these patterns remain poorly understood. Here, we study how sex differences in parental investment and mating competition coevolve with parental care specialization. Parental investment often consists of two or more distinct activities (e.g. provisioning and defence) and parents may care more efficiently by s…
Model details from Sex roles and the evolution of parental care specialization
Details of the mathematical model, including the case of shared parentage
Model details from Sex roles and the evolution of parental care specialization.
Details of the mathematical model, including the case of shared parentage
The evolution of mating preferences for genetic attractiveness and quality in the presence of sensory bias.
The aesthetic preferences of potential mates have driven the evolution of a baffling diversity of elaborate ornaments. Which fitness benefit—if any—choosers gain from expressing such preferences is controversial, however. Here, we simulate the evolution of preferences for multiple ornament types (e.g., “Fisherian,” “handicap,” and “indicator” ornaments) that differ in their associations with genes for attractiveness and other components of fitness. We model the costs of preference expression in a biologically plausible way, which decouples costly mate search from cost-free preferences. Ornaments of all types evolved in our model, but their occurrence was far from random. Females typically p…