process and analyse information from secondary sources to explain a modern example of ‘natural’ selection
Here is a starting point
Antibiotic resistance World Health Organisation
And here is an example of a way science may be able to slow or stop the evolution of mosquitoes resistance to insecticides.
Evolution-proof insecticides may stall malaria forever Andrew Read The Pennsylvania State University, Center for Infectious Disease Dynamics, April 2009
Sample explanation
Some organisms, such as bacteria and insects, produce large numbers of offspring.
Amongst large numbers of bacteria offspring, some individuals may carry genes that give them resistance to antibiotics. These individuals are then able to survive and reproduce with reduced competition from other members of the same species. Each generation will produce a higher percentage of individuals containing the resistant genes. This has been the story for antibiotics since they were first used. The initial use of an antibiotic results in good protection from bacteria. Over time the chemicals become less and less effective. A case study provides a good example of how natural selection occurs. A similar situation occurs in the resistance of insects to insecticides.
Selecting those individuals that are able to survive and reproduce increases the frequencies of those genes in the population. This is “survival of the fittest” where the fittest are those that have a natural resistance to a selecting factor, which in the case of bacteria described above, is antibiotics.
(You are required to process and analyse one example, not just have a general knowledge of these principles. You should be able to quote at least two different sources of information)