∞ generated and posted on 2016.08.29 ∞
Increases in population sizes by some constant fraction of the total number of individuals present a given amount of time earlier.
Often what is considered is either a population's rate of doubling or the amount increase per generation, though numbers other two, or times other than generation are just as legitimate. Thus, a population could increase ten-fold every year (1 → 10 → 100 → 1000) over three years or 1.5-fold per generation (1 → 1.5 → 2.25 → 3.375 → 5.0625) over four generations.
Note in particular how the absolute increase in population size is continuously increasing over time whereas the relative increase remains constant. Exponential growth is only possible if no limits on organism population growth exist within environments, which is more likely if organism densities are quote low relative to what is known as environmental carrying capacities.