Question
Peppered moths are normally white with black speckles across the wings, giving it its name. This patterning makes it well camouflaged against lichen-covered tree trunks when it rests on them during the day.
There is also a naturally occurring genetic mutation, which causes some moths to have almost black wings. These black forms (called 'melanic') are not as well camouflaged on the lichen as normal 'peppered' forms, so they are more likely to be eaten by birds and other predators. This means that fewer black forms survive to breed, so they are less common in the population than the paler peppered forms. This is the normal situation observed in the countryside of Britain and Ireland.
However, in the nineteenth century it was noticed that in towns and cities it was actually the black form of the moth that was more common than the pale peppered form. Industrialization and domestic coal fires had caused sooty air pollution, which had killed off lichens and blackened urban tree trunks and walls. So, it was now the pale form of the moth that was more obvious to predators, while the melanic form was better camouflaged and more likely to survive and produce offspring. As a result, over successive generations, the black moths came to outnumber the pale forms in our towns and cities.
In the mid-twentieth century, controls were introduced to reduce air pollution and, as the air quality improved, tree trunks became cleaner and lichen growth increased. Once again, the normal pale Peppered Moths were camouflaged and the black forms were more noticeable. Now the situation in urban areas has again become the same as in the countryside, with normal pale Peppered Moths being far more common than the black forms. So, natural selection has been seen to work in both directions, always favoring the moth that is best suited to the environmental conditions. The same thing has been observed throughout Europe and the USA.
Write a CER statement concerning the following prompt:
Evaluate the claim that the peppered moth example is strong evidence for evolution by natural selection.
There is also a naturally occurring genetic mutation, which causes some moths to have almost black wings. These black forms (called 'melanic') are not as well camouflaged on the lichen as normal 'peppered' forms, so they are more likely to be eaten by birds and other predators. This means that fewer black forms survive to breed, so they are less common in the population than the paler peppered forms. This is the normal situation observed in the countryside of Britain and Ireland.
However, in the nineteenth century it was noticed that in towns and cities it was actually the black form of the moth that was more common than the pale peppered form. Industrialization and domestic coal fires had caused sooty air pollution, which had killed off lichens and blackened urban tree trunks and walls. So, it was now the pale form of the moth that was more obvious to predators, while the melanic form was better camouflaged and more likely to survive and produce offspring. As a result, over successive generations, the black moths came to outnumber the pale forms in our towns and cities.
In the mid-twentieth century, controls were introduced to reduce air pollution and, as the air quality improved, tree trunks became cleaner and lichen growth increased. Once again, the normal pale Peppered Moths were camouflaged and the black forms were more noticeable. Now the situation in urban areas has again become the same as in the countryside, with normal pale Peppered Moths being far more common than the black forms. So, natural selection has been seen to work in both directions, always favoring the moth that is best suited to the environmental conditions. The same thing has been observed throughout Europe and the USA.
Write a CER statement concerning the following prompt:
Evaluate the claim that the peppered moth example is strong evidence for evolution by natural selection.
Answers
GPT-4o mini
**Claim:** The peppered moth example is strong evidence for evolution by natural selection.
**Evidence:** The case of the peppered moth exhibits clear instances of natural selection in response to changing environmental conditions. Initially, in a pre-industrial environment, the pale peppered moths were better camouflaged against lichen-covered tree trunks, enhancing their survival and resulting in a predominance of this phenotype. However, with industrialization, pollution altered the environment, favoring the melanic (black) form of the moth as it became better camouflaged against sooty tree trunks. This shift in the population dynamics demonstrated a direct relationship between environmental factors and the survival of different moth phenotypes. As air quality improved in the mid-twentieth century, the natural selection process reversed, leading to a resurgence of pale moths as they regained their camouflage advantage.
**Reasoning:** The peppered moth example illustrates the principles of natural selection, showcasing how changes in the environment can lead to shifts in the allele frequencies within a population. The observable changes in the population of moths in response to pollution and subsequent environmental recovery provide a strong, concrete example of how organisms adapt to their surroundings. Furthermore, the repeated, documented instances of selection pressure favoring different phenotypes at different times align with the fundamental concepts of evolution, reinforcing the idea that natural selection is a driving force behind evolutionary change. Thus, this example effectively supports the claim that natural selection is a key mechanism in evolution.
**Evidence:** The case of the peppered moth exhibits clear instances of natural selection in response to changing environmental conditions. Initially, in a pre-industrial environment, the pale peppered moths were better camouflaged against lichen-covered tree trunks, enhancing their survival and resulting in a predominance of this phenotype. However, with industrialization, pollution altered the environment, favoring the melanic (black) form of the moth as it became better camouflaged against sooty tree trunks. This shift in the population dynamics demonstrated a direct relationship between environmental factors and the survival of different moth phenotypes. As air quality improved in the mid-twentieth century, the natural selection process reversed, leading to a resurgence of pale moths as they regained their camouflage advantage.
**Reasoning:** The peppered moth example illustrates the principles of natural selection, showcasing how changes in the environment can lead to shifts in the allele frequencies within a population. The observable changes in the population of moths in response to pollution and subsequent environmental recovery provide a strong, concrete example of how organisms adapt to their surroundings. Furthermore, the repeated, documented instances of selection pressure favoring different phenotypes at different times align with the fundamental concepts of evolution, reinforcing the idea that natural selection is a driving force behind evolutionary change. Thus, this example effectively supports the claim that natural selection is a key mechanism in evolution.