To help your investigation, here is some more data about the farm.
The chicken population was started with chicks from a different farm.
Chickens are raised in barns where bacteria can spread easily between chickens.
CJ, E. Coli, and Salmonella bacteria are all present in the barns.
Some of the E. Coli and Salmonella bacteria have alleles that make them resistant to the FQ antibiotic.
To stop disease from growing in the barn, the FQ antibiotic is fed to the chickens a lot.
Choose which way of evolution caused the FQ antibiotic resistance.
Gene Flow
Genetic Drift
Natural Selection
What is the best fit option here? Form a hyptothesis
This is my hypothesis, is it right ?
If the chicken population is consistently given the FQ antibiotic, then natural selection leads to antibiotic resistance, because some chickens could have some of the bacterias that develop mutations allele and they can resist against FQ antibiotics.Bacteria which are resistant will continue to increases and grows in number over time. In the end, the chicken population are mainly resistant bacterial, thus making this the likely mechanism of evolution.
The Correct Answer and Explanation is:
Your hypothesis is on the right track, and the best fit option for the evolution of antibiotic resistance in the chicken population is Natural Selection. Here’s an explanation that elaborates on this concept:
Explanation of Natural Selection and Antibiotic Resistance
Natural selection is a key mechanism of evolution where organisms with traits that enhance survival and reproduction are more likely to pass on those traits to the next generation. In the context of the chicken population on the farm, the consistent administration of the fluoroquinolone (FQ) antibiotic creates a selective pressure on the bacteria present in the barns, particularly E. coli and Salmonella.
- Initial Population: When the chickens were introduced to the barns, they carried a variety of bacteria, some of which may have had natural mutations that conferred resistance to the FQ antibiotic. In a normal environment without antibiotics, these bacteria would compete equally with non-resistant strains.
- Selective Pressure: By regularly feeding the chickens FQ antibiotics, the environment becomes hostile to susceptible bacteria. The antibiotic kills off most of the non-resistant bacterial strains, leaving behind those that have alleles for antibiotic resistance.
- Survival of the Fittest: The resistant bacteria, having survived the selective pressure, continue to reproduce. This leads to an increase in the proportion of resistant bacteria within the population over time. As these resistant strains thrive and reproduce, the overall genetic makeup of the bacterial community shifts towards antibiotic resistance.
- Long-term Consequences: Eventually, the majority of bacteria in the barn will be resistant to the FQ antibiotic. This can pose serious risks not only to the health of the chickens but also to human health, as resistant strains can potentially spread to other animals or humans.
In summary, your hypothesis effectively captures the essence of natural selection as a mechanism for the development of antibiotic resistance in bacteria. The consistent use of FQ antibiotics creates a situation where only those bacteria that possess resistance genes can survive and thrive, leading to an evolution in the bacterial population towards increased resistance.