Ecology Quiz - Chapters 9-11 PDF

Anna O’Brien Ecology Quiz - Chapters 9-11 Chapter 9: Social Behavior and Eusociality Costs and Benefits of Living in Groups Costs: ○ Predation and Parasitism: Groups are more visible to predators, and dense groups spread disease faster. ○ Aggression: Te...

Anna O’Brien Ecology Quiz - Chapters 9-11 Chapter 9: Social Behavior and Eusociality Costs and Benefits of Living in Groups Costs: ○ Predation and Parasitism: Groups are more visible to predators, and dense groups spread disease faster. ○ Aggression: Tensions can rise within the group. ○ Resource Sharing: Food and resources are divided among all members. Benefits: ○ Group members gain protection and resources, increasing survival and reproductive chances. Territories Definition: An area defended by one or more individuals. Purpose: Ensures access to resources like food and nesting sites. Types: ○ Transient: Temporary, e.g., migratory birds defending areas during travel. ○ Permanent: Maintained as long as the benefits outweigh defense costs. Dominance Hierarchies Definition: Ranking system within a group based on contests for dominance. Function: Reduces conflict by quickly determining access to resources. Structure: ○ The highest-ranked individual dominates all others. ○ Lower ranks hold power over those below them in the hierarchy. Types of Social Interactions 1. Cooperation: Both donor and recipient benefit. 2. Selfishness: Donor benefits at the recipient's expense. 3. Spitefulness: Both donor and recipient are negatively affected. 4. Altruism: Donor sacrifices for the recipient’s benefit.  Direct Fitness: Gained by passing on genes directly to offspring. Indirect Fitness: Gained by helping relatives pass on shared genes. Inclusive Fitness: Sum of direct and indirect fitness. Altruism and Kin Selection Hamilton’s Rule: Altruism is favored when: B×r>CorCB C \quad \text{or} \quad \frac{C}{B} < rB×r>CorBC​1\lambda > 1λ>1: Population increases. λ