Lecture on Mating and Inclusive Fitness

Mating and Associated Behaviors

• Mating: Pairing of opposite-sex organisms for reproduction and propagation of genetic material.
  • Includes the act of mating and other behaviors associated with the process.
  • Example: Superb bird of paradise performs an elaborate dance to attract a mate.

Mating Behaviors

• Pre-mating behaviors: These can include things like mating dances.
  • Example: Male superb bird of paradise.
• Post-mating behaviors: Actions that occur after mating, such as nest-building or feeding the young.

Mating Strategies

1. Random Mating

• All individuals within a species are potential partners.
• Not influenced by environment, heredity, or social limitations.
• Ensures a large amount of genetic diversity.

2. Non-Random Mating

• Not all individuals are equally likely to be chosen as mates.

Assortative Mating

• Individuals with similarities (genotypes or phenotypes) mate more frequently.
  • Example: Large animals mate with large animals; small animals with small animals.
• Potential risk: Increases the likelihood of in-breeding and passing harmful recessive traits.

Disassortative Mating

• Opposite of assortative mating.
• Individuals with different traits mate more frequently than in random mating.

Inclusive Fitness

• Inclusive Fitness: Number of offspring an animal has, how they support them, and inter-support among offspring.
• Broadens the concept of fitness beyond individual reproduction.
• Advantageous to promote reproduction and survival of closely related individuals due to shared genes.

Implications of Inclusive Fitness

• Explains altruistic behavior: Rather than acting only for individual benefit, organisms also act for the benefit of relatives sharing common genes.
• Real-world support: Humans are more altruistic towards those sharing the same last name, a cue for genetic relatedness.

Important Concepts to Remember

• Random Mating: Promotes genetic diversity.
• Assortative Mating: Similar individuals mate; risk of in-breeding.
• Disassortative Mating: Different individuals mate.
• Inclusive Fitness: Evolutionary advantage in supporting the reproduction and survival of relatives.