HANDTOMOUTH develops a framework for understanding archaeological and fossil evidence for the evolution of speech and manual dexterity. We focus on low-order parameters which can potentially be assessed in fossil and archaeological evidence. The focus will be on motor control in complex, serially ordered, goal-directed movements, with two sub-themes: Speech production. This will include physical and digital modelling of vocal tracts of extinct hominins based on anatomical parameters, to recover the range of articulatory manoeuvres and acoustic characteristics. There will also be a comparative anatomical study of primate cranial nerves, which will address a neural substrate for speech motor control and sensory feedback regulation. The modelling will include small-scale perturbations of the model system to determine which components of the vocal tract are most sensitive in terms of effects on sound characteristics, and this will enable prediction of which cranial nerves may have increased sensory fibres as a speech-related adaptation. Tool use. This will address the relationship between action understanding and the self-generation of action sequences in human and non-human primates. It will include activation analysis of cortical motor circuits in the action system of nonhuman primates in sequentially complex action observation tasks, and kinematic analysis movement control in stone tool-making and other tool-using tasks in healthy and apraxic human subjects. As a unifying framework, we intend to re-evaluate the possibility that tool use may have co-evolved with speech, reflecting shared features of neural architecture. We identify possible areas of convergence and/or homology in behavioural organization and in neural architecture in the two systems. HANDTOMOUTH will enable us to evaluate the extent to which their co-evolution in humans was necessary or contingent (and with a better understanding of the evidential controls).