The capacity for language is very difficult to identify from the fossil evidence.  Explain the main characteristics that are used to investigate the language capabilities of human ancestors.

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The main characteristics used to identify language capability in the fossil record are:

The hyoid bone: This bone, to which muscles of the tongue and neck attach, is positioned low and forward in the human neck, compared to that of chimps and other mammals.  This means that the tongue can be controlled more efficiently and more intricate movements are possible.

Basicranium morphology: Language is associated with a larynx that is positioned low in the neck.  The base of the crania is flexed when the larynx is low in the neck (as in adult humans) and flat when the larynx is high in the neck (as in human infants, primates and mammals).

Hypoglossal canal and oral cavity: The hypoglossal canal, which surrounds the nerve that controls the tongue muscles, has been found to be larger in humans and some pre-human hominoids.  The human oral cavity is shorter than that of chimps, which allows the tongue to reach the points required for the production of consonant sounds, and some of the muscles are positioned in different places and at different angles.

Endocasts: Broca’s and Wernicke’s areas have been associated with the ability to produce and perceive language respectively, although the story is more complicated than this.

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