HOW DID NATURAL SELECTION OCCUR IN THE BRITISH PEPPERED MOTH?
Natural selection is particularly evidenced in the British Peppered Moth. In England, the common shade of the peppered moth was light grey, however this was before the English Industrial Revolution occurred. The natural light grey moths were very similar in colour to the lichen-covered trees of England, which proved to be useful in survival against predators (such as birds) since they were camouflaged in the trees. The mutated version of the peppered moth had a variant gene that caused the colour to be very dark. This was very rare (approximately 2%). These darker-coloured moths were easily preyed upon since they were not hidden by the colour of the environment, sticking out against lightly coloured trees. This proved to be survival disadvantage.
However, when the English Industrial Revolution happened, the environment was drastically altered by the vast amounts of pollution and smog. The colour of the trees surrounding the English cities soon became dark, similar to the shade of the mutated peppered moths. Suddenly, with decades, the population of dark peppered moth increased, with the gene frequency of about 98%. The light-colored moths were now very easily spotted against the darken trees. The gene frequency of the light-coloured moths dropped to about 2% of the population.
The survival advantage was now possessed those previously disadvantaged. Natural selection took control. Now that the darker moths were best-suited to the changing environment, reproductive partners began to select them over the lighter moths, since the darker ones had the survival advantage. The darker ones also usually live longer now, because of lack of predation, leaving the darker moths to reproduce more heavily, passing on their variant gene to the next generation of peppered moths.
Today, with controlled air pollution and less smog in the air, the trees around cities have now returned to their original lighter colour, resulting in a resurgence of lighter-coloured peppered moths. Since they can now better camouflage against the trees, the lighter moths are more frequently observed. They are also not preyed upon now and reproducing more offspring. The darker moths are now less frequent, with the variant gene leaving the majority of the population.
Natural selection is particularly evidenced in the British Peppered Moth. In England, the common shade of the peppered moth was light grey, however this was before the English Industrial Revolution occurred. The natural light grey moths were very similar in colour to the lichen-covered trees of England, which proved to be useful in survival against predators (such as birds) since they were camouflaged in the trees. The mutated version of the peppered moth had a variant gene that caused the colour to be very dark. This was very rare (approximately 2%). These darker-coloured moths were easily preyed upon since they were not hidden by the colour of the environment, sticking out against lightly coloured trees. This proved to be survival disadvantage.
However, when the English Industrial Revolution happened, the environment was drastically altered by the vast amounts of pollution and smog. The colour of the trees surrounding the English cities soon became dark, similar to the shade of the mutated peppered moths. Suddenly, with decades, the population of dark peppered moth increased, with the gene frequency of about 98%. The light-colored moths were now very easily spotted against the darken trees. The gene frequency of the light-coloured moths dropped to about 2% of the population.
The survival advantage was now possessed those previously disadvantaged. Natural selection took control. Now that the darker moths were best-suited to the changing environment, reproductive partners began to select them over the lighter moths, since the darker ones had the survival advantage. The darker ones also usually live longer now, because of lack of predation, leaving the darker moths to reproduce more heavily, passing on their variant gene to the next generation of peppered moths.
Today, with controlled air pollution and less smog in the air, the trees around cities have now returned to their original lighter colour, resulting in a resurgence of lighter-coloured peppered moths. Since they can now better camouflage against the trees, the lighter moths are more frequently observed. They are also not preyed upon now and reproducing more offspring. The darker moths are now less frequent, with the variant gene leaving the majority of the population.