There was no assurance that early man would even survive. Jumps between plateau levels would likely have been exponential. Indeed, the exponential growth rate of the last 300 years or so can be thought of as one long jump to a new plateau which has been raised artificially high by technology. Those who imagine that eight people gave rise to all living today according to a simple exponential growth curve have demonstrated an inability to think things through. Let's look at the equation involved in these growth rate calculations.
P is the initial population which, in our case, is eight.
The growth rate is r which would be close to zero for humanity per year. A negative value would indicate a population decline. However, since the flood supposedly reduced the population to eight people 1656 years after creation, a figure Dr. Hovind gives based on patriarchal ages, we should start our exponential curve at the latter date. If we assume, for the sake of this argument, that the earth is 6000 years old, then we start our calculation with 8 people 4344 years ago. We must wind up with the present population of 5.5 billion people, the figure given by Dr. Hovind.