William D. Hamilton

Definition

William D. Hamilton was a prominent British evolutionary biologist known for his groundbreaking work in the field of sociobiology and evolutionary theory, particularly in relation to kin selection. His ideas about how natural selection operates not just on individuals but also on genes laid the foundation for understanding social behavior in animals and humans alike. Hamilton's theories have profoundly influenced how we think about evolution, altruism, and the social structures within species.

5 Must Know Facts For Your Next Test

1. Hamilton introduced the concept of kin selection in his 1964 paper 'The Genetical Evolution of Social Behavior', which revolutionized our understanding of social interactions among animals.
2. He proposed the theory of inclusive fitness as a way to explain why some animals engage in altruistic behaviors that seem to lower their own chances of survival or reproduction.
3. Hamilton's Rule states that altruistic behavior is favored by natural selection when the cost to the altruist is less than the benefit to the recipient multiplied by the degree of relatedness between them.
4. His work has had significant implications for fields beyond biology, influencing psychology, anthropology, and even economics in understanding human behavior.
5. Hamilton's legacy includes not only his theoretical contributions but also his fieldwork in studying social insects and other species that exhibit complex social behaviors.

Review Questions

• How did William D. Hamilton's work on kin selection change our understanding of social behavior in animals?
  • William D. Hamilton's research on kin selection transformed how scientists view social behavior by showing that natural selection can favor actions that benefit relatives, even at a cost to the individual's own reproductive success. This idea challenges traditional views of selfishness as the primary driver of evolution and highlights the importance of genetic relatedness in shaping social interactions. His insights into how genes influence altruistic behaviors opened up new avenues for research into both animal societies and human social dynamics.
• Discuss the implications of Hamilton's Rule for understanding altruistic behavior in animal populations.
  • Hamilton's Rule provides a mathematical framework for predicting when altruistic behavior will evolve based on costs and benefits. Specifically, it suggests that an individual is more likely to exhibit altruism towards another if the benefits to the recipient outweigh the costs to the altruist, adjusted for their genetic relatedness. This principle helps explain behaviors such as cooperative breeding in birds or warning calls in social animals, where individuals may risk their own safety for the sake of their relatives, thereby ensuring the propagation of shared genes.
• Evaluate how William D. Hamilton's contributions to evolutionary biology have influenced interdisciplinary fields beyond biology.
  • William D. Hamilton's contributions to evolutionary biology have significantly impacted various disciplines, including psychology, anthropology, and economics. His theories on kin selection and inclusive fitness have led researchers in these fields to reexamine human behaviors through an evolutionary lens, recognizing the role of genetic relatedness in shaping cooperation and social structures. By framing human interactions as influenced by evolutionary pressures, Hamilton's work encourages a deeper understanding of cultural phenomena such as familial bonds and social norms, ultimately integrating biological principles into the study of complex human societies.

Related terms

Kin Selection: A form of natural selection where individuals are more likely to help their relatives survive and reproduce, thereby increasing the likelihood of shared genetic material being passed on.

Sociobiology: An interdisciplinary field that examines social behavior in a biological context, integrating principles from both sociology and evolutionary biology.

Inclusive Fitness: A concept introduced by Hamilton that expands the traditional notion of fitness to include the reproductive success of an individual's relatives, weighted by their degree of genetic relatedness.