The best definition of evolutionary fitness is:
a. Physical health
b. The ability to attract members of the opposite sex
c. The ability to adapt to the environment
d. Survival and reproduction relative to other members of the population
e. Overall strength

Verified step by step guidance

1. Step 1: Understand the concept of evolutionary fitness. Evolutionary fitness refers to an organism's ability to survive and reproduce in its environment, passing on its genes to the next generation. It is not solely about physical health, strength, or attractiveness but rather about reproductive success relative to others in the population.
2. Step 2: Analyze the options provided in the question. Each option represents a potential definition of evolutionary fitness. Carefully evaluate each one based on the concept of evolutionary fitness.
3. Step 3: Eliminate incorrect options. For example, 'physical health' (option a) and 'overall strength' (option e) are not accurate definitions because they do not directly relate to reproductive success. Similarly, 'the ability to attract members of the opposite sex' (option b) is only a part of the process and not the full definition.
4. Step 4: Consider the remaining options. 'The ability to adapt to the environment' (option c) is important for survival but does not fully encompass the concept of evolutionary fitness, which also includes reproduction. 'Survival and reproduction relative to other members of the population' (option d) is the most accurate definition because it directly ties to the organism's reproductive success compared to others.
5. Step 5: Conclude that the best definition of evolutionary fitness is the one that emphasizes both survival and reproduction relative to others in the population, as this aligns with the biological understanding of fitness in evolutionary terms.

Key Concepts

Evolutionary Fitness

Evolutionary fitness refers to an organism's ability to survive and reproduce in its environment compared to other members of the same species. It encompasses not just physical health or strength, but also how well an organism can adapt to changing conditions and successfully pass on its genes to the next generation.

Natural Selection

Natural selection is the process through which certain traits become more or less common in a population based on their impact on survival and reproduction. Organisms with advantageous traits are more likely to survive and reproduce, thereby increasing the frequency of those traits in future generations, which is a key mechanism of evolution.

Reproductive Success

Reproductive success is a measure of how many offspring an organism produces that survive to reproductive age. It is a critical component of evolutionary fitness, as it directly influences the genetic contribution of an individual to the next generation, shaping the evolutionary trajectory of a population.