Question

if a species has unlimited growth potential,why doesn't fill the earth

Answer 1

growth potential is not the only factor that determines the size of the population..competition for food,mate,resources...dangers from predators..also have an important role in the size of a population...
do you think of any other important factors?????

Answer 2

pressure competition i guess, lack of food resources, areas considered as barriers in species dispersal.

Answer 3

another way of thinking of this, is that growth potential is calculated at a specific time for a specific species,etc in a specific environment. As time changes, the growth potential also changes do the the stressors listed by @BIOCRYSTAL and @babybaby .