In a population of deer there are two alleles, p and q. Individuals with allele p are faster than those with allele q and so are better at avoiding predation by wolves. Explain how natural selection will affect the characteristics of the deer population.

In the population, there is genetic variation with some individuals possessing allele p and some possessing allele q. Predation by wolves acts as a selection pressure on the genetic variation in the population. Individuals with allele p are less likely to be killed by wolves and so are more likely to survive to reproduce than individuals with allele q. This means p individuals have a higher reproductive success than q individuals. Over many generations the proportion of the population possessing allele p will increase and more individuals will be able to run at the faster speed. This change in allele frequency and subsequent change in the running speed of the population is known as evolution by natural selection.