I have already mentioned that the human species differs from other animal species because of its advanced neocortex which enable humans to create language, art, myth and culture, and to make plans and create a self-image as well as a worldview. I also mentioned differences in DNA between the species. Humans and chimpanzees share 98.8 % of their DNA. Nevertheless, the species are very different in several ways. This is because two identical stretches of DNA can work very differently. Humans and chimpanzees use their genes in different ways, and even though the same genes are expressed in the same brain area in both species, they are expressed in different amounts. Hence already on a biological, neurological level, humans can be said to be unique, if we mean by unique that they have features no other animal species have.