How does the development of antibiotic resistance in a population of bacteria support the theory of evolution through natural selection?

1 Answer
Jun 22, 2017

Evolution can be loosely defined as a change in a population - if the population changes over a period of time, and that change is an adaptation that improves fitness, it supports the theory.

Explanation:

Evolution by natural selection could be better defined as a change in the allele frequencies of a population in response to an external "selective" pressure.

This pressure (predators, limited resources, antibiotics) results in differential fitness in a population - those bacteria with the allele for resistance are better suited to survive than those without and as a result are more often successful at reproducing.

Over time, a population of bacteria will become resistant to an antibiotic in response to a constant selective pressure (application of antibiotics) - the frequency of resistance alleles in the gene pool will increase which we can define as "Evolution".