Final answer:
In an evolutionary context, an individual's fitness relates to their relative ability to survive and reproduce compared to others in their population, which is key to the passing on of genes to future generations.
Step-by-step explanation:
When we speak of an individual's fitness in an evolutionary sense, we are referring to their relative fitness, which is an individual's ability to survive and reproduce compared to the rest of the population. Fitness is a measure of how well an organism can pass on its genes to the next generation, and it is influenced by various factors such as an organism's ability to find food, avoid predators, and attract mates. Being fit in this context does not necessarily mean being the strongest or the fastest; instead, it relates to any trait that increases the likelihood of survival and reproduction of one's genetic material.