Still, the matter of the series is fascinating, even if it is conveyed in a slightly confusing mix of documentary and am-dram reconstructions. While hunting for fossils in 1974 Johanson stumbled over a knee- joint. He was looking for the elusive connection between our nearest known ancestors, the apes, and early humans, and these little pieces of bones didn't fit his preconceptions.
It had been thought that the missing link would be something that walked a bit like an ape but thought a bit like a human - in other words, that expanded brain- size was the trigger for our evolution. The knee-joint belonged to a three-and-a-half- foot-high skeleton which the team named Lucy (represented here by a small actress in very urgent need of a depilatory) and it suggested the exact opposite - that our ancestors had first learnt to walk upright and that increased brain size had followed later. Nature found work for idle hands, which had previously been occupied in getting about but which could now expand their repertoire.
After some three million years of tinkering they had come up with the flame- thrower, a hellish piece of human ingenuity which had seared the memories of those who saw it used during the Second World War on the island of Saipan. In Secret History (C4), which told of how many Japanese troops and civilians committed suicide rather than surrender to American GIs, one veteran recalled the peculiar mewing noise it made, repeating it again and again as though it was a nagging tune he couldn't shake.
The film made much of the Japanese propaganda that persuaded the defenders that it was better to do almost anything rather than surrender, but made slightly less of the American propaganda that allowed ordinary boys not to trouble themselves too much about who was inside the caves they were cauterising. But then the American propaganda (stories of a cruel and tenacious enemy) was a lot closer to the truth. Two Japanese survivors recalled how children had been murdered because their crying might have revealed a hiding place - in one case the mothers had been ordered to kill their own babies by soldiers who feared for their lives.
When American troops closed in, having fought their way across the island, hundreds leapt from cliffs as helpless soldiers looked on. Others had killed themselves earlier, crowding tightly round a single Japanese conscript who would then pull the pin on a grenade. 'In our group the hand grenade wouldn't go off,' one old lady said. 'That's the only reason I survived.' She remembered the soldier hammering it desperately to get it to work, an odd sort of memory for a grandmother to have.
The pressure not to surrender wasn't simply a matter of immediate fear. One soldier, who had hidden for months and had been declared dead, recalled the mixed reception when he got home, the embarrassment of having a dead hero transformed to a living son. 'My father's face expressed ambiguous emotions,' he said. Though the film didn't mention it, it's an intriguing fact that Saipan is now quite a popular holiday resort for Japanese tourists, with tours of the suicide cliffs and caves a speciality.