CAPE Biology Unit 1 · 2013 · Paper 2 · Question 5(a)(i)

Mycobacterium tuberculosis, the bacterium that causes tuberculosis, has been virtually eliminated by the widespread use of two effective antibiotics. Due to the development of antibiotic-resistant strains of the bacterium, the disease has re-emerged as a major public health problem.

Applying Darwin's theory of evolution by natural selection, discuss how resistance to antibiotics could have evolved in bacteria. Include in your discussion a concise explanation of natural selection.