Theodosius Dobzhansky (1937), Paul Nurse (2020), and many others, propose that evolution is crucial to any understanding of how biology works. Noam Chomsky (2022) proposes that this includes language.

By the proposal here, in this evolution there must have been at least seven steps, the last being the least thoroughly fixated and the most vulnerable to developmental mishap. It should be said that this idea is not endorsed by Chomsky who proposes that human speech and language evolved by a single evolutionary step, and thus that there has never been any such thing as a ‘protolanguage’.

This proposal at least reduces any need for postulating specific malformations, as proposed by Lawrence Shriberg et al (2005) and innumerable others in the same tradition. Shriberg suggests that it is necessary to postulate particular ‘phenotypes’ of disorder. The proposal here at least diminishes, if it doesn’t eliminate, the case for any specific malformations.

An evolutionary model reverses the thinking here. It simplifies the theory of disorder. as required in science generally, by an idea generally known as ‘Occam’s razor’ (William of Ockham lived in the 14th century).

In learning to talk there is a lot to learn.