Group selection

Definition

Group selection is an evolutionary theory that suggests natural selection operates not only at the level of individuals but also at the level of groups. This means that behaviors beneficial to a group can be favored by selection, even if they are costly for individuals. It highlights how cooperation and altruism among members of a group can enhance the group's overall fitness and survival, leading to evolutionary advantages.

5 Must Know Facts For Your Next Test

1. Group selection can explain behaviors like altruism, where individuals may sacrifice their own interests for the good of the group, thus enhancing the group's overall survival.
2. The theory posits that groups with more cooperative members are more successful at surviving and reproducing compared to groups with selfish members.
3. Group selection contrasts with individual selection, which focuses on how traits benefit individual organisms rather than groups.
4. Examples of group selection can be seen in social insects, such as bees and ants, where individuals work together for the hive or colony's success.
5. Critics of group selection argue that it is less powerful than individual selection, but many researchers now accept that both levels of selection can work in tandem.

Review Questions

• How does group selection differ from individual selection in terms of evolutionary advantages?
  • Group selection differs from individual selection in that it considers the fitness benefits to entire groups rather than just individual organisms. While individual selection focuses on traits that enhance an individual's survival and reproductive success, group selection emphasizes behaviors that may benefit a group's overall success, even if they come at a personal cost. This perspective helps explain cooperative behaviors, as groups with higher levels of cooperation may outcompete less cohesive groups.
• Discuss how group selection can influence the development of cooperative behaviors in animal societies.
  • Group selection influences the development of cooperative behaviors by favoring traits that enhance group fitness over those that only benefit individuals. In animal societies where cooperation is crucial for survival, such as in hunting or defense against predators, individuals that engage in altruistic behavior may help ensure the entire group's survival. As a result, over generations, these cooperative traits become more common within the population, leading to stronger social bonds and improved group performance.
• Evaluate the implications of group selection for understanding human social behavior and cultural evolution.
  • Evaluating group selection's implications for human social behavior reveals insights into our tendencies for cooperation and altruism within communities. As humans evolved in complex social groups, behaviors promoting group cohesion likely enhanced our survival and reproductive success. Cultural evolution also reflects these dynamics, as societies that cultivate cooperation may outlast those driven solely by individualistic pursuits. Understanding this interplay between group selection and human behavior helps clarify why collaboration remains vital in our societies today.

Related terms

kin selection: A type of natural selection that favors behaviors that help relatives, increasing the chances of shared genes being passed on to future generations.

altruism: Behavior by an individual that increases the fitness of another individual while decreasing the actor's own fitness, often seen in cooperative species.

reciprocal altruism: A form of altruism where individuals provide benefits to others with the expectation that those benefits will be returned in the future.