70 likes | 194 Views
KEY CONCEPT Social behaviors enhance the benefits of living in a group. Living in groups also has benefits and costs. Social behaviors evolve when the benefits of group living outweigh its costs. benefits: improved foraging, reproductive assistance, reduced chance of predation
E N D
KEY CONCEPT Social behaviors enhance the benefits of living in a group.
Living in groups also has benefits and costs. • Social behaviors evolve when the benefits of group living outweigh its costs. • benefits: improved foraging, reproductive assistance, reduced chance of predation • costs: increased visibility, competition, disease contraction • Group living requires learning social structure and membership.
Social behaviors are interactions between members of the same or different species. • Animals use communication to keep in contact. • visual • sound • touch • chemical
Courtship displays are used to evaluate the fitness of a potential mate. • Defensive behaviors are used to protect the individual and/or the group.
Some behaviors benefit other group members at a cost to the individual performing them. • There are many types of helpful social behavior. • cooperation • reciprocity • altruism
In altruism, an individual reduces its own fitness to help other members of its social group. • inclusive fitness • kin selection
Eusocial behavior is an example of extreme altruism. • Eusocial species live in large groups of mostly nonreproductive individuals. • haplodiploid species: social insects (wasps, bees, ants) Minorworker Majorworker Queen • diploid species: termites, snapping shrimp, naked mole rats • Eusocial behaviors likely evolve by kin selection.