Language evolutionists are split over the application of the Darwinian Theory of natural selection in the explanation of language evolution. It was put forth by Pinker & Bloom (1990) that human language may have evolved by a process of biological natural selection. The human language system and its intricate cognitive requirements are explained by the development of the human brain and other organs of great complexity as a means of natural selection. Furthermore, the design features of language analysed as part of language evolution research suggest that human language is a product of natural selection, and its evolution has then enhanced humans capacity to communicate and socialise interdependently (Pinker, 2003).

The archaeological research of the Neanderthal fossils and genes also further provide evidence for a proto-language between the Neanderthal and humans with common lexical semantics (Johansson, 2013). Despite the indisputable fact that humans have language and speech while other non-human species do not, the discovery of the new DNA evidence shows a relationship between the Neanderthal and humans. This reaffirms the strong relevance of natural selection in the study of language evolution.

There are however also arguments and disagreement with the application of the Darwinian theory in the explanation of language systems used by humans and animals. Penn, Holyoak & Povinelli (2008) remarked that the differences between humans and non-humans have been downplayed, claiming that there is a lack of continuity in the approximation of complex, “systematic relational capabilities of a physical symbol system”. They also attempted to further show that this lack of continuity is also exhibited in every other domain of cognition in humans and has an intricate structure that cannot be merely explained by the prevalence of language and culture of humans. This complexity is perceived to be the difference that would mark humans from non-humans, against the Darwinian theory of gradual evolution. However, Burghardt (2008) disagrees with their argument as he finds it problematic the authors ignored the relevance of semantics in human language. Herman, Uyeyama and Pack (2008) contested the authors’ claim that the functional differences between human and non-human using the evidence of bottlenose dolphins’ relational capabilities.

In this wikichapter, Theory of Mind and functions of the FOXP2 gene are examined in relation to the explanation of language being a biological adaptation.