If no more people were to be born the law of Population growth would strongly resemble the radioactive decay law Discuss this statement?

Answer 1

I don't think you can say that. Radioactive decay is an inverse exponential process, where the number of disintegrations per unit of time is a function of the amount of material present. We measure this in half-lives, with half of the remaining material removed after each half life. (1/2, 1/4, 1/8, 1/16, 1/32, etc.) Population decay in the absence of a Birth Rate, however, would be a function of the probability of death, and the highest predictor of that probability is age. You would not expect people to live longer just because there are fewer of them. Population decay would depend on the distribution of ages in the population. If that distribution were uniform, the decay would be linear, not inverse exponential. If the distribution were highly non uniform, such as everyone remaining being the same age, then the population decay would be abrupt, with everyone dying at the same statistical time. In order to say that population decay is the same as radioactive decay, you would have to say that half the population is younger than the median age, and half of the remaining population is younger than the median age of that subset, and so forth. Since the birthrate is not proportional to the population, as only younger people have babies, this is not true.