The act of distinguishing or describing a thing, by giving its different, or specific difference; exact definition or determination.
The gradual formation or production of organs or parts by a process of evolution or development, as when the seed develops the root and the stem, the initial stem develops the leaf, branches, and flower buds; or in animal life, when the germ evolves the digestive and other organs and members, or when the animals as they advance in organization acquire special organs for specific purposes.
The supposed act or tendency in being of every kind, whether organic or inorganic, to assume or produce a more complex structure or functions.
There have only been about a half dozen genuinely important events in the four-billion-year saga of life on Earth: single-celled life, multicelled life, differentiation into plants and animals, movement of animals from water to land, and the advent of mammals and consciousness. Elon Musk
In the animal world, on the other hand, the process of evolution is characterised by the progressive discrimination of the animal and vegetative functions, and a consequent differentiation of these two great provinces into their separate departments. Wilhelm Wundt