Tracing missing persons can take much patientdetective work. But a special kind of “private eye” cantrace the missing ancestors of whole peoples by

　　studying the clues buried by words. __1__

　　These philologists, such as the language detectives arecalled, have traced __2__

　　the word trail back from peoples in Europe, India,South Africa, the Americas,

　　and the Pacific islands in a tiny nameless, and forgotten tribe that roamed central__3__

　　Eurasia 5000 to 6000 years ago, before the dawn of writing history. __4__

　　Since a long time scholars have been puzzled over the striking __5__

　　difference of words in different languages. In Dutch, vader; in Latin, pater;in __6__

　　old Irish, athir; in Persian, pidar;in the Sanskrit of distant India, pitr.

　　These words all sounded likely and meant the same thing—“father” __7__

　　Where did it happen that widely separated peoples used such __8__

　　close related sound symbols? The problem baffled linguists for years. The more so__9__

　　because “father” was but one of a host of such coincidences. Towards the end

　　of the 18 century it dawned on scholars that perhaps all these words stemmed__10__

　　from some common language.