By Peter DearloveFour young people were taken from their tribe in the remote land of Tierra del Fuego as ransom for a stolen boat in 1830, yet they were treated like celebrities and introduced to the British King and Queen in London. When they were taken home it seemed they had everything they needed to bring prosperity and progress to their kith and kin.No one speaks it any more. The people for whom Yaghan was once an intricate and rather music…