Kin selection

Definition

Kin selection is an evolutionary strategy that favors the reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction. This concept helps explain behaviors like altruism and cooperation among closely related individuals, connecting deeply with ideas about fitness, social structures, and conflict within families.

5 Must Know Facts For Your Next Test

1. Kin selection can lead to altruistic behaviors, where individuals help relatives at their own expense, ultimately enhancing the overall genetic success of related individuals.
2. The concept was notably formalized by W.D. Hamilton in 1964, who introduced the idea of inclusive fitness as a means of explaining the evolution of social behaviors.
3. Kin selection plays a crucial role in various social structures, especially in animal societies where individuals live in groups with close genetic relationships.
4. In parent-offspring conflict, kin selection explains how parents invest more in offspring that share more genes with them, which can sometimes lead to conflicting interests.
5. Sibling rivalry is also influenced by kin selection as siblings compete for resources; however, cooperation among siblings can emerge when it benefits their shared genetic interests.

Review Questions

• How does kin selection relate to the concepts of inclusive fitness and altruism?
  • Kin selection is closely tied to inclusive fitness because it emphasizes the importance of supporting relatives for reproductive success. By favoring the survival of closely related individuals, kin selection encourages altruistic behavior, where one individual may sacrifice its own interests for the benefit of relatives. This mechanism ensures that shared genes continue to be passed down through generations.
• Discuss how kin selection can be observed in cooperative breeding and its implications for animal societies.
  • In cooperative breeding systems, individuals often help raise offspring that are not their own but are genetically related. Kin selection drives this behavior because helping relatives increases the chances of shared genes being passed on. This cooperation can strengthen social bonds within groups and improve overall survival rates of the young, showcasing how kin selection shapes complex social structures in animal societies.
• Evaluate the role of kin selection in parental investment strategies and its effects on sibling rivalry.
  • Kin selection significantly influences parental investment strategies as parents are likely to allocate resources preferentially towards offspring that share a greater proportion of their genes. This can lead to sibling rivalry when siblings compete for those limited resources, potentially resulting in conflicts over parental care. However, under certain circumstances, kin selection may encourage cooperative behaviors among siblings, leading them to work together for mutual benefit instead of merely competing.

Related terms

Inclusive fitness: Inclusive fitness refers to an individual’s overall genetic success through both direct reproduction and by supporting relatives, thereby increasing the survival of shared genes.

Altruism: Altruism is a behavior that benefits another individual at a cost to oneself, often observed in species where kin selection influences social behaviors.

Cooperative breeding: Cooperative breeding is a social system where individuals assist in raising offspring that are not their own, often seen in species with strong kin ties.