The peppered moth- Evolution and natural selection

• Before the industrial revolution, in the 1800s, most peppered moths were of the pale variety. this meant that they were camouflaged against the pale birch trees that they rested on
• Moths with a mutant black coloring were easily spotted and eaten by birds. this gave the white variety an advantage, and they were more likely to survive and reproduce.
• During the last half of the 1800s, airborne pollution in industrial areas blackened the birch tree bark with soot. This meant that the mutant black moths were now camouflaged, while the white variety became more vulnerable to predators. This gave the black variety an advantage, and they were more likely to survive and reproduce.
• the dark moths passed on the alleles for black wing color leading to offspring with the black wing color phenotype.
• over time, the black peppered moths became far more common in urban areas than the pale variety.
• The change in phenotype was not due to pollution making the moths darker. this variety had always existed, but it was the best suited variant when the environment changed. it took many generations before the population of moths was mainly black in color.