Manual communication systems: evolution and variation

This chapter addresses issues in the evolution and typology of manual communication systems. From a language evolution point of view, sign languages are interesting because it has been suggested that oral language may have evolved from gestural (proto)language. As far as typology is concerned, two issues will be addressed. On the one hand, different types of manual communication systems, ranging from simple gestural codes to complex natural sign languages, will be introduced. The use and structure of two types of systems - tactile sign languages and secondary sign languages - will be explored in more detail. On the other hand, an effort will be made to situate natural sign languages within typological classifications originally proposed for spoken languages. This approach will allow us to uncover interesting inter-modal and intra-modal typological differences and similarities