The evolution of the peppered moth 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 mellaniam. Later, when pollution was reduced, the light-coloured form again predominated. Industrial melanism in the peppered moth was an early test of Charles Darwin natural selection in action, and remains as a classic example in the teaching of evolution.
A. Sponges
They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like Mesohly sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohly in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes.