Robert Trivers

Definition

Robert Trivers is an influential American evolutionary biologist known for his work on the theory of parental investment, which examines how parental behavior impacts the evolution of reproductive strategies. His research emphasizes the role of mate selection and the evolutionary conflicts between parents and offspring, providing a foundational understanding of various aspects of animal behavior, especially in relation to reproductive strategies and parental roles.

5 Must Know Facts For Your Next Test

1. Trivers proposed that the sex investing more in offspring tends to be choosier about mates, while the less investing sex competes for access to them.
2. His work highlights that conflicts can arise between parents and offspring over the amount of parental investment provided, as each has different evolutionary interests.
3. Robert Trivers also introduced concepts related to reciprocal altruism, which explains how cooperation can evolve among non-relatives through mutual benefit.
4. He emphasized the importance of genetic relatedness in shaping behaviors that promote survival and reproductive success within family units.
5. Trivers' research has been influential across various disciplines, including psychology, sociology, and anthropology, furthering our understanding of human and animal social behaviors.

Review Questions

• How does Robert Trivers' theory of parental investment explain differences in mating behaviors between sexes?
  • Robert Trivers' theory of parental investment suggests that the sex that invests more time and resources in offspring tends to be more selective in choosing mates. For instance, females often invest heavily in their young through gestation and nursing, leading them to be more discerning in mate selection. In contrast, males typically invest less in offspring and may compete for access to multiple females, thus exhibiting different mating strategies shaped by their respective investment levels.
• Discuss the implications of Trivers' work on parent-offspring conflict in terms of evolutionary biology.
  • Trivers' work on parent-offspring conflict illustrates that parents and their offspring can have opposing interests regarding resource allocation. Parents may wish to spread their investments among multiple offspring for overall survival success, while individual offspring may want a larger share for themselves. This conflict leads to an evolutionary tug-of-war where each side evolves strategies to maximize their own fitness, resulting in complex behavioral adaptations that influence parenting styles and offspring development.
• Evaluate how Robert Trivers' theories on reciprocal altruism contribute to our understanding of social behaviors in both animals and humans.
  • Robert Trivers' theories on reciprocal altruism suggest that individuals engage in cooperative behaviors with the expectation of future reciprocation. This concept deepens our understanding of social dynamics by explaining how such altruistic behaviors can evolve even among non-relatives if they enhance overall fitness through mutual benefits. In both animal societies and human interactions, these principles help clarify why individuals might sacrifice resources or time for others—promoting social bonds that can ultimately lead to greater collective survival and reproductive success.

Related terms

Parental Investment Theory: A theory that explains how the time and resources parents invest in their offspring affect the offspring's survival and reproductive success, shaping evolutionary strategies.

Sexual Selection: A mode of natural selection where individuals with certain inherited traits are more likely than others to obtain mates, influencing reproductive behaviors and mating patterns.

Kin Selection: A type of natural selection that favors behaviors that help relatives, increasing the likelihood of shared genetic traits being passed on to future generations.