3. Briefly summarize in your own words what alternative explanations have been proposed for melanism that do not have to do with bird predation.

Answer & explanation:

Melanism occurs due to a genetic mutation that causes the excessive and concentrated production of the black pigment, called melanin. The consequence is living beings with darkened skin or fur. There are three types of melanism.

Adaptive melanism occurs by the need to adapt to the environment, a condition that will be passed through the generations. This melanism allows animals to camouflage themselves during hunting or to hide from predators.

Industrial melanism is related to human interference, especially industrial activities, in the lives of animals (dark-colored moths are the best-known cases). Air contamination is one of the main factors for this condition.

There is also pseudo-melanism, which partially affects animals and is generally motivated by genetic mutations. In certain species, the characteristic spots and stripes appear larger and darker than usual. This type of melanism is very present in cats such as tigers, cheetahs, leopards. However, other animals can still be affected.