query : chomsky 's " single mutation " on page 43 of his 1977 paper ` language origin theories ' , in duane rumbaugh 's book _ language learning by a chimpanzee _ , gordon hewes asserts that chomsky has explicitly attributed the human language faculty to a single genetic mutation in our ancestors . he gives as his source " chomsky ( 1967 ) " , but , exasperatingly , neither this work nor any other work by chomsky is listed in his bibliography , nor is it obvious what work he might have been citing . can anyone point me to any places in chomsky 's writings ( or , indeed , in anyone else 's writings ) in which such a suggestion is explicitly made ? all i ' ve been able to find is chomsky 's repeated suggestions that our language faculty might have arisen as a by-product of other developments and hence as something not subject to natural selection , but that 's not quite the same thing . larry trask cogs university of sussex brighton bn1 9qh england larryt @ cogs . susx . ac . uk