How does antibiotic resistance of bacteria demonstrate various principles of evolution?

Question

Sebastian Alvarez · Accepted Answer

Good question! I would ask u to go through this link before reading the answer below.

Accepted evolutionary theory is based on few facts which could be applicable to bacteria as well, for example:

1. there are genetic variations present in a gene pool of population

2. variations are omnipotent; generally such preadaptive characters are already present in some organisms which derive benefit in a new/changed environment

In some bacteria resistance against specific antibiotics could be naturally present and such variations would help those organisms to survive an onslaught of specific antibiotic chemicals. Thus resistant bacteria will exhibit:

3. survival of the fittest; in this case fittest are the resistant bacteria

Bacterial organisms without any resistance to antibiotic would fail to reproduce in an environment loaded with antibiotic chemicals but resistant bacteria of the population will successfully multiply, that too in faster rate because of less number of competing bacteria present in the environment. Thus:

4. the 'fittest' shows differential reproduction, hence favorable variations increase in frequency in the genepool

In this case 'selection' is not absolutely natural, but due to application of antibiotic by human.

5. Selection of organisms with favourable variation in each generation with time changes the genepool and the population is said to have evolved with time

I could enlist five points which elaborate the basic concepts of evolution in light of antibiotic resistance as seen in bacteria.

Lydia Adams · Answer

undefined Antibiotic resistance in bacteria demonstrates several principles of evolution, including natural selection, genetic variation, and adaptation. When antibiotics are used, they kill susceptible bacteria, but some bacteria with genetic mutations that make them resistant survive and reproduce, passing on their resistance traits. Over time, this leads to the predominance of resistant strains, illustrating natural selection and the survival of the fittest. The genetic variation among bacteria allows for some to have traits that provide an advantage in the presence of antibiotics, showcasing how variation can lead to adaptation in response to environmental pressures, a fundamental aspect of evolution.