Species have a natural tendency to produce more offspring than the environment can support

• An overproduction of offspring improves the chances that some will survive to reproduce and maintain continuity
  

• Large amounts of offspring increases the genetic diversity of the population – making it more resilent to changing conditions
  

If left to follow course, a population will inevitably outgrow its resource base, leading to competition for survival

• When there is an abundance of resources, a population will grow according to its biotic potential (exponential J-curve)
  

• With more offspring, there are less resources available to other members of the population (environmental resistance)
  

• This will lead to a struggle for survival and an increase in the mortality rate (causing population growth to slow and plateau)

This concept is central to Darwin’s understanding of ‘survival of the fittest’ – any trait that is beneficial for competitive survival will be more likely to be passed on to offspring according to natural selection

• Competition can be either infraspecific (between members of a species) or interspecific (between different species)
  

• Resources that may become limiting include food, water, shelter and access to sunlight
  

Population Growth