Final answer:
The scientist is correct in claiming the function is linear if the population changes at a constant rate over equal time intervals, as this is the definition of linear growth in the context of population dynamics.
Step-by-step explanation:
When assessing whether a population growth function is linear, it is essential to understand what a linear function represents in this context. A linear function suggests that the population grows by a constant rate over equal time intervals. In other words, if you look at the population size at any two points in time, the increase from one point to the next will be the same. This is represented by a straight line on a graph of population size over time.
Therefore, if a scientist claims a function is linear because the population changes at a constant rate per unit interval relative to time, the scientist is correct. This corresponds to option 1).
If the function were not linear, you would see a variable rate of population change, which may look more like exponential or logistic growth. Exponential growth occurs when the rate of population increase becomes larger as the population grows, and logistic growth occurs when the population increase starts to slow down as it approaches a carrying capacity.