Writing has been reinvented from within non-literate communities at least seven times in recent history. The best known example is that of the Cherokee script developed by Sequoyah in 1821. This was followed by the Vai script (Liberia, ca. 1833), the Bamum script (Cameroon, ca. 1903), the Alaska script (1901-1905), the Caroline Islands script (1905-1909), Masaba (Mali, 1930), and Pahawh Hmong (Vietnam, 1955-1971). [Footnote: A further six might be added to this list but the state of literacy of their inventors remains unknown. Paleographers suspect that "stimulus diffusion" may also account for the appearance of several ancient scripts including Linear A, Cretan Hieroglyphic, Proto-Sinaitic and Anatolian Hieroglyphics)]. Three out of these seven scripts were created in West Africa alone, a zone of sustained colonial contact with high linguistic diversity and rich indigenous graphic traditions.
Of these scripts we contend that the Vai script of Liberia is the best candidate for evolutionary analysis, for a number of reasons. The script was created by at least eight men (Forbes 1851, Ellis 1914) who knew of the Arabic and Roman scripts but were not literate in either of them and certainly did not apply them as models. Although schools for teaching the script were active between ca.1835 and 1850 (Koelle 1854; Migeod 1909), its transmission has remained informal and non-institutionalised for most of its history. Those who wish to learn the language must seek out a literate individual to teach them on a voluntary basis \cite{Scribner_1981}. The teaching itself follows no prescribed method: there is no recitation order or reference syllabary meaning that apprentices learn-by-doing (Tuchscherer pers. comm.). Footnote: this saturation method is attested since at least 1899 (REF Delafosse) but rote learning and recitation methods are also recorded (Delafosse 1899, Dalby 1967, Scribner and Cole see grammatogeny sheet]. This means, in effect, that if certain characters are not needed in a communication, there may never be occasion to learn them at all. Only two attempts to standardise the Vai script have ever been made. The first in 1901, and a second more successful campaign in 1962. For all these reasons we might expect that Vai writers have used their scripts under conditions of relative freedom giving variation and change the best chance to emerge. Finally, the script has been independently documented on fifteen separate occasions between 1834 and 2005 meaning that most of it history is adequately recorded and does not require any interpretive reconstruction.