“When you realize the value of all life, you dwell less on what is past and concentrate more on the preservation of the future.”  The last entry in Dian Fossey’s diary is poignant enough without its proximity to the primatologist’s brutal murder in 1985. Fossey was killed in her cabin in the Virunga Mountains of Rwanda, where she had observed and lived among the silverback gorillas for decades. The killer was never satisfactorily identified – poachers? gold-smugglers? Fossey’s own assistant? – but let’s “dwell less on what is past” and remember her life this week, when she would have turned 91.