Tuberculosis
Should we be concerned?
The History...
In the 1950s two effective antibiotics changed the course of this deadly disease for what seemed like forever. A disease once responsible for thousands of deaths seemed to be gone forever...however recently a NEW strand of this deadly disease has developed and this strand isn't going down without a fight. As of right now the strand is resistant to antibiotics. But where did it come from?
Mutations
The resistant bacteria has a single base change form cytosine to thymine and this is REPRODUCING and PASSING ON this mutation to its offspring.
Because of this mutation the antibiotic cannot bind to the RNA polymerase an prevent transcription.
Natural Selection Factors
Genetic Variation
The mutant bacteria vary from the original bacteria hence are not effected by the antibiotics.
Survival of the Fittest
The mutant bacteria are immune to the antibiotics making them better able to cop in their environment.
Reproduction
The non-resistant bacteria are killed, making the mutant bacteria numbers surpass the non-mutant numbers.
Analysis...
So how is this Evolution?
The TB bacteria has evolved due to this one single mutation and more importantly the mutation is one that can be passed on to offspring!