I. The problem
Humans: a biological being
As a biological being, humans are part of nature and, like all other living beings, have developed over the course of evolution. The development of the human mind can therefore also only be explained appropriately on the basis of Darwin’s theory of evolution.
In 1758 Carl von Linné incorporated man into his taxonomic work Systema Naturae, which is still fundamental today. He placed humans quite naturally next to their next animal relatives, the great apes, and summarised both in an order, which he later called primates (master animals).
He defended himself against criticism related to this approach, arguing that he could find no significant difference between the skeletons of humans and those of apes.
Charles Darwin, who published his second major work on The Descent of Man (1871) after The Origin of Species (1859) referred to forerunners and allies of the theory of descent:
The conclusion that humans, like other species, descended from an old, deep, extinct form is by no means new. It was drawn long ago by Lamarck as well as later by several outstanding naturalists and philosophers such as Wallace, Lyell, Huxley, Vogt, Lubbock. Büchner, Rolle, and especially Ernst Haeckel. (German edition, Frankfurt/M. 2009, p. 11)
In the first chapter of The Descent of Man Darwin justifies the development of humans from the animal kingdom with a wealth of examples, based on the bodily structure and embryonic development of humans in comparison to higher animals – two topics for which there was sufficient material available at the time.
Today, the results of paleontological research and molecular biology can also be used to justify human evolution from the animal kingdom. For this reason, human evolution in the sense of Darwin’s theory of evolution is one of the standard statements of modern science.