Question

In the case of peppered moth (Biston betularia) the black-coloured form became dominant over the light-coloured form in England during industrial revolution. This is an example of

• A. appearance of the darker coloured individuals due to very poor sunlight
• B. protective mimicry
• C. inheritance of darker colour character acquired due to the darker environment
• D. natural selection whereby the darker forms were selected

Hint:

Natural selection refers to the mechanism by which populations of living organisms adapt and adjust to the environment. 

Answer 1

The Correct Option is D

During post industrialisation period, the tree trunk became dark due to industrial smoke and spots. 

• White-winged moths didn't survive because of the predators.
• Dark-winged moths survived as against a dark background they were not easily seen by predators. 
• Thus industrial melanism supports evolution by natural selection that favours the establishment of one particular advantageous mutation within a population.

In the case of the peppered moth (Biston betularia) the black-coloured form became dominant over the light-coloured form in England during the industrial revolution. This is therefore an example of natural selection whereby the darker forms were selected.

Answer 2

The shift in the heritable characteristics of a population over generations is a central mechanism of evolution by Charles Darwin.

Complete answer:

Biston betularia is a temperate genus of the peppered moth. The evolution of the peppered moth is sometimes used as an indicator of natural selection. 

• The evolution of the peppered moth during the industrial revolution is an example of colour variation in moths. 
• It basically focuses on increasing the number of dark-coloured moths due to industrial emissions and a mutual decrease in the clean environment of the population. 
• The phenomenon is, therefore known as industrial melanism.

Additional Information:

Natural selection refers to the mechanism by which populations of living organisms adapt and adjust to the environment. 

• Individuals are inherently different in a population in certain ways. 
• This difference suggests that certain people have characteristics that are better suited to the environment than others.
• Individuals with adaptive characteristics are more likely to survive and replicate the characteristics that give them some benefit of survival. 
• These people pass on the adaptive features to their offspring. 
• These beneficial traits are becoming more prevalent in the population over time. 
• Through this process of natural selection, desirable characteristics are transmitted through generations.

Speciation, when one species gives birth to a new species, can lead to natural selection. It is one of the mechanisms that drive change and helps to clarify the diversity of life on Earth.

So, the correct answer is option D) ‘Natural selection, whereby the darker forms were selected’.

Answer 3

The correct option is (D) “Natural selection whereby the darker forms were selected.”

Explanation:

The given case is an example of natural selection, where as a result of a struggle for existence, only those organisms could survive which have favourable variations in order to adapt to the environmental conditions. 

• With so many variations in the population of species the struggle for existence results in survival of the fittest. 
• The survival of the fittest is the result of the selection and proliferation of only those organisms which were most suitably adapted to the environment and most successful in mating i.e. natural selection.

Explanation of incorrect options:

Option A:

1. Sunlight is not a factor in the appearance of the darker-coloured individuals

Option B:

1. Protective mimicry is when a species benefits from predation by mimicking non-beneficial species.
2. It also comes under the natural selection law.
3. This option is not correct as dark-coloured moths were not mimicked from any other species

Option C:

1. Inheritance of darker colour characters acquired due to the darker environment comes under the natural selection law.

Final answer: In the case of the peppered moth (Biston betularia) the black-coloured form became dominant over the light-coloured form in England during the industrial revolution. This is an example of natural selection whereby the darker forms were selected.