Exploring the Complicated Role of Evolutionary Modeling Help versus Harm

Help versus Harm Altruism Consider two populations: 1. All conditional altruism in Help 2. All conditional spite in Harm Suppose we let recognition evolve in these populations 1. Recognition selected against in Help 2. Recognition is selected for in Harm Help (Prisoner’s Dilemma) altruism egoism altruism b-c b egoism -c 0 Harm (Prisoner’s Delight) egoism spite egoism 0 -c spite -h -h-c b = benefit from altruism h = harm from spite c = cost to help or harm Combining Help and Harm Combining Help and Harm • Consider a population where individuals play Help with probability p and Harm with probability (1-p) Combining Help and Harm • Consider a population where individuals play Help with probability p and Harm with probability (1-p) • Four strategies: E : egoism in both A : conditional altruism in Help S : conditional spite in Harm C : conditional altruism in Help and conditional spite in Harm Coevolution • Populations are represented by two vectors: one for type frequencies, one for recognition ability • Recognition ability can range from 0 and 1 • Individuals meet at random • Evolution occurs according to the replicator dynamics acting on both type frequencies and recognition ability simultaneously Frequency Strategy Evolves 1 0.8 A E S C 0.6 0.4 0.2 0.2 0.4 0.6 0.8 Probability of Playing Help Consequences Consequences • The standard story: cooperation evolves first in favorable conditions followed by punishment to enforce it • Punishment interpreted as altruism and poses a second-order free rider problem Consequences • The standard story: cooperation evolves first in favorable conditions followed by punishment to enforce it • • Punishment interpreted as altruism and poses a second-order free rider problem We have an alternative to the standard story about the evolution of punishment • Conditional spite may evolve first, stabilize recognition, allow cooperation to evolve later • Conditional spite may coevolve with conditional altruism Consequences Consequences • This scenario reverses the order of evolution • Conditional harming may have evolved first • And it may be crucial for maintaining the very mechanisms that enable cooperation Consequences • • This scenario reverses the order of evolution • Conditional harming may have evolved first • And it may be crucial for maintaining the very mechanisms that enable cooperation There is a persistent challenge: the evolution of social behavior is a complicated affair and more formal work needs to be done to provide any help to paleobiological research Wrapping up Wrapping up • What should our attitude be towards the usefulness of evolutionary modeling for paleobiology? Wrapping up • What should our attitude be towards the usefulness of evolutionary modeling for paleobiology? 1. On molecular tests for selection: optimistic, especially when augmented with information on gene function Wrapping up • What should our attitude be towards the usefulness of evolutionary modeling for paleobiology? 1. On molecular tests for selection: optimistic, especially when augmented with information on gene function 2. On cooperation and cognitive complexity: less optimistic, especially given the potential evolutionary role of spite The coincidence The coincidence • Disparate instances of evolutionary modeling: molecular sequence evolution versus evolution of social behavior The coincidence • Disparate instances of evolutionary modeling: molecular sequence evolution versus evolution of social behavior • Yet both are missing the same crucial component: demographic information on population size and structure