Evolutionary Fitness

Definition of Fitness

• Fitness refers to the success of a genotype in leaving offspring in the next generation, compared to other genotypes.
• Fitness is about survival and reproduction, not physical strength or exercise.
• Example: Brown beetles that produce more offspring than green beetles due to their color are considered to have higher fitness.

Relative Nature of Fitness

• Fitness is dependent on the environment; a genotype that is fit in one context (e.g., during an ice age) may not be the fittest in another context.

Components of Fitness

• Fitness encompasses all factors crucial to natural selection:
  • Survival
  • Mate-finding
  • Reproduction
• It is not necessarily linked to being the strongest or fastest.

Strategies that Increase Fitness

• Caring for offspring
• Producing a large number of young (even if many do not survive)
• Developing traits that attract mates (e.g., peacock feathers)
• These strategies can be costly to individual survival but enhance fitness by ensuring more offspring reach the next generation.

Sexual Selection

• A form of natural selection focused on mate-finding and reproductive behaviors.

Additional Resources

• Learn more about fitness through various contexts:
  • "Survival of the Sneakiest" comic strip
  • "Conserving the Kakapo" news brief
  • "Evolution from a Virus's View" news brief
  • "Killer Whales Fitness Boost" after offspring grow news brief

Conclusion

• Fitness is a comprehensive concept encompassing survival, reproduction, and mate-finding efficiency.
• It is context-dependent and extends beyond physical attributes, involving strategies that promote genetic propagation in future generations.