The evolution of the peppered moth is an evolutionary instance of directional colour change in the moth population as a consequence of air pollution during the Industrial Revolution. The frequency of dark-coloured moths increased at that time, an example of industrial melanism. Rest of the detail can be read here.
Peppered moths are single-brooded – reproducing only once a year, while the adult moths are seen flying between May and August, mating with each other. The female peppered moths lay up to 2000 eggs in clusters, giving birth to caterpillars between 10 to 14 days. The caterpillars mimic the twigs or branches of trees.
Peppered moths are common insects living in England, Europe, and North America . They are small moths, only 1.5 to 2.5 inches across. Their light wings are “peppered” with small dark spots. Light and dark peppered moth larvae. Image by Rockpocket via Wikimedia Commons.
You could be thinking “Where do peppered moths live in the UK?”
Biston betularia is widespread in Europe, Asia and North America and is actively seen in the UK during the months of May to August. In the daytime, peppered moths rest on the barks, leaves, and branches of trees , where they are camouflaged from predators such as birds.
An answer is that like many moths in forests, the peppered moth tends to rest (or “perch”) on tree trunks during the day. They do most of their flying at night .
Is the peppered moth the proof of evolution?
This is the transcript of Majerus’ lecture given at the European Society for Evolutionary Biology meeting on 23 August 2007.
Since moths are short-lived , this evolution by natural selection happened quite quickly. For example, the first black Peppered Moth was recorded in Manchester in 1848 and by 1895, 98% of Peppered Moths in the city were black.
What is an example of a peppered moth?
, and peppered moth. The peppered moth (Biston betularia) is a temperate species of night-flying moth. Peppered moth evolution is an example of population genetics and natural selection . The caterpillars of the peppered moth not only mimic the form but also the colour of a twig.
This of course begs the inquiry “What is the peppered moth an example of?”
Our chosen answer was Later, when pollution was reduced, the light-coloured form again predominated. Industrial melanism in the peppered moth was an early test of Charles Darwin ‘s natural selection in action, and remains as a classic example in the teaching of evolution .
Here is what our research found. the other form, carbonaria, is a much darker color that is peppered with light speckles . Moth collectors in England noted that most peppered moths collected in the early 1800’s were light gray peppered with bits of black. Many years later most of the moths collected were almost completely black.
How did the peppered moth change from light to dark?
Scientists bred the moths and figured out that the light-colored form of the peppered moth has different genes from the dark form. The black color of the dark form was due to a mutation in the DNA of the light-colored form . Once this mutation was present, the dark-colored moths would produce offspring with dark-colored.
Another frequently asked inquiry is “Can peppered moths change color?”.
You see, since all of the moths can’t be the same color then the parents passed on traits. The peppered moths also changed color because of the evolution . At first the moths were this color, then when they were growing, the moths began to change color. Also the peppered moths in the light forests did not change color because they didn’t live ina place where there were factories or the pollution.
A question we ran across in our research was “Why are some moths black in color?”.
Our answer is that the black color of the dark form was due to a mutation in the DNA of the light-colored form . Once this mutation was present, the dark-colored moths would produce offspring with dark-colored wings. Light colored adults that didn’t have the mutation produced light offspring. But genetics is only part of the story.
Some think that historic moth collections show both speckled and black forms existed before the industrial revolution, so the moth has not changed colour – all colours options existed before any selection took place. The only recorded change has been the proportion of speckled and black forms in succeeding generations as the industrial revolution came and went.