I mean each Animal has a purpose in order to keep the food chain in line, for example sharks if they went extinct there would be more seals and more fish and less of this and that. Each animal plays a certain part on earth in order to keep everything normal.
They will not mix because the oil does not have a chemical charge large enough to break the hydrogen bonds between the water molecules.
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.