What does variation in fitness imply in the context of natural selection?

Variation in fitness in the context of natural selection indicates that some individuals within a population possess traits that enhance their ability to survive and reproduce in a given environment. This concept is foundational to the theory of evolution, as it suggests that those individuals with advantageous traits are more likely to pass these traits on to their offspring. These advantageous traits can include physical characteristics, behaviors, or physiological traits that give them a survival edge, enabling them to find food, avoid predators, or withstand harsher environmental conditions.

The presence of variation in fitness means that not all organisms are equally suited to their environments; rather, there is a differential survival and reproduction based on the traits individuals possess. Over time, this process can lead to changes in the frequency of these traits in the population, shaping the evolutionary path of the species. Understanding this principle is crucial for grasping how natural selection drives evolution and how certain characteristics become more common within biological populations.