“Masters of the Planet” by Ian Tattersall:
Tattersall maintains that the notion of human evolution as a linear trudge from primitivism to perfection is incorrect. Whereas the Darwinian approach to evolution may be viewed as a fine-tuning of characteristics guided by natural selection, Tattersall takes a more generalist view. Tattersall claims that individual organisms are mind-bogglingly complex and integrated mechanisms; they succeed or fail as the sum of their parts, and not because of a particular characteristic. In terms of human evolution, Tattersall believes the process was more a matter of evolutionary experimentation in which a new species entered the environment, competed with other life forms, and either succeeded, failed, or became extinct within that environment: “To put it in perspective, consider the fact that the history of diversity and competition among human species began some five million years ago when there were at least four different human species living on the same landscape. Yet as a result of evolutionary experimentation, only one species has prospered and survived. One human species is now the only twig on what was once a big branching bush of different species.” This idea differs from the typical view that homo sapiens is the pinnacle of an evolutionary ladder that humanity’s ancestors laboriously climbed.