Question

Explain how this experiment showed that genetic drift was not a cause of the antibiotic resistance.

Answer 1

An experiment showed that antibiotic resistance in bacteria comes from pre-existing resistance genes rather than genetic drift or mutations caused by antibiotic exposure. This was observed when bacteria with resistance genes survived antibiotic treatment and reproduced, demonstrating natural selection.

Step-by-step explanation:

The experiment demonstrating that antibiotic resistance is not due to genetic drift involved exposing a population of bacteria to antibiotics, thereby selecting for bacteria already resistant to antibiotics. Resistance arises from pre-existing genes, not as a direct consequence of the antibiotic application. This is evidenced by the fact that when bacteria are exposed to antibiotics, only those with resistance genes survive and reproduce, consistent with the principles of natural selection rather than random changes as seen in genetic drift.

Additionally, the concept of lateral gene transfer is important in the context of antibiotic resistance. Strains of bacteria can exchange genetic material, such as plasmids containing resistance genes, which can quickly spread resistance across different bacteria populations, further underscoring the role of gene transfer over genetic drift.

Answer 2

Antibiotic resistance happens naturally due to genetic mutation through random selection, however, genetic drift occurs on purpose and tests which genes are stronger and should continue to be passed on to future generations.