A type of population  growth  in  which  the  rate of increase in the number of members is proportional to the number present. Exponential   growth   involves   an   increasing rate  of   growth:   the   more   individuals there are, the faster the population increases. A graph of number against time in such growth has a J-shaped curve. In practice,   exponential   growth   does  not coritinue indefinitely. Other factors (e.g. shortage of food) become important and slow down the growth rate. The resulting curve is S-shaped (sigmoid). See also  logarithmic phase.  
			 |