Final answer:
Fitness refers to the relative ability of an organism to survive and produce fertile offspring in the context of natural selection. Fit can also be used to determine goodness-of-fit in statistical analysis, as well as how well a case study aligns with certain rules.
Step-by-step explanation:
Fitness refers to the relative ability of an organism to survive and produce fertile offspring in the context of evolution by natural selection. It is often measured by scientists and can be quantifiable. However, what matters is not an individual organism's absolute fitness, but rather how it compares to other organisms in the population.
Fit can also be used in the context of determining the goodness-of-fit in statistical analysis. In this case, it is used to decide whether a population with an unknown distribution fits a known distribution based on qualitative survey questions or experimental outcomes.
In the context of fish assemblages, fit can refer to how well a particular case study aligns with certain rules for integration. A good fit indicates that the case study aligns well with the rules, while a poor fit suggests a misalignment.