Evidence for Evolution: Resistant Bacteria

Evolution usually takes millions of years. However, bacteria can evolve very quickly because they reproduce at a fast rate.

In the past, many people died from bacterial diseases. However, doctors started treating these diseases with antibiotics, such as penicillin. An antibiotic is a substance that inhibits the growth and reproduction of bacteria or kills them outright. Antibiotics are widely used in medicine to treat pathogenic bacteria that can cause life-threatening diseases.

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However, when bacteria mutate, they can produce new strains. Some of these strains are resistant to certain antibiotics. This evolution of bacteria supports Darwin’s theory of evolution by natural selection.

The main stages of bacteria developing resistance are:

1. A random mutation occurs in the DNA of individual bacterial cells.

• Some mutations protect the bacteria against the antibiotic

2. Bacteria without the mutation die, whereas those with the mutation survive and reproduce without competition from non-mutated bacteria.

3. Over time, the population of antibiotic-resistant bacteria grows. As the antibiotic is ineffective against this strain, the bacteria will start to spread.

Reducing the Development of Antibiotic Resistance

The overuse of antibiotics has largely contributed to the rise in antibiotic resistance. For example, MRSA (methicillin-resistant staphylococcus aureus) is a dangerous bacterium because it is resistant to most antibiotics.

There are ways to reduce the development of antibiotic-resistant strains:

• Doctors should only prescribe antibiotics to patients when it is necessary and avoid using them for non-serious infections or viruses.

• Patients should complete the course of antibiotics, even if they feel better. This kills all the bacteria so that none survive and mutate into resistant strains.

• Restrict the use of antibiotics in agriculture.