Although humankind has been using techniques that may be described as biotechnological for centuries, the term itself only came into common usage in the early part of the twentieth century. In the past, biotechnology might have involved things like artificial selection processes for improving the ability of certain crops to survive, for example. Then, there is hybridisation, a way in which people have made entirely new sub-species for themselves. These days, biotechnology includes all sorts of molecular-level processes to engineer the biologies of both plants and animals. It covers bio-manufacturing, bio-engineering, medicine production, gene therapies and food production, among many other aspects.