Answer:
This population
Step-by-step explanation:
The characteristic feature of a population is the ability of the organisms of the geographical region to mate( interbreed) and produce a fertile offspring. This is what maintains the population growth and increase the gene pool. However this feature may be affected by variation in the genetic composition of the species which results in diverse organisms, with different survival rates.
Generally population vary in size,and every population has tendency to undergo exponential growth, However certain biotic and abiotic factors usually prevent exponential growth, thereby serving as limiting factors suppressing the tendency of exponential growth by the population,
Favourable abiotic factors( sunlight, rainfall, wind,) increases population towards exponential growth,and biotic factors( predators, diseases narrow the sizes of the population to maintain the balance so that the growth will not alter balance in the ecosystem.
The effect of density dependent factors on population depends on the specific characteristics of the population size. For example a fish pond densely populated with different species of fishes, will readily be fed on by kingfishers, crocodiles, alligators, compare to a pond which is sparse with few fishes of .
Besides the rate of maturation of an organism in the gene pool is another example of how characteristic of population can affect population size due to density dependent factor, A population with gene pool of rapidly maturing species will dense, rich, and well inviting for predators to prey on reducing the population growth.
Genetic variation in the population usually favour directional selection of organisms who inherited trait which are most fitted for survival in the gene pool. They are most likely to withstand fluctuations in selective pressures and therefore have better adaptation to populate the habitats. However, if the selective pressure is too high for them to bear they my die, and therefore favour the populations of the less fitted organism. This is population bottle neck.
However population bottle neck may lead to extinction if the environmental factors changes and the less fitted organism failed to adapt to the habitat. This explains the reasons for extinction of certain population