The Science of Discworld II

years – comes in and takes over from the amateur cichlid catfish. Unfortunately, in this case, it wasn’t an inoffensive catfish, but the Nile perch, a specialised carnivore from an ancient stock. The Nile perch has now cleaned out nearly all of the Lake Victoria cichlid explosion, which is why we wrote the previous passage in the past tense. 4 The main remnants of that glorious radiation of the cichlids are now to be found in the homes of a few amateur hobbyists, who are keeping some of the odd cichlid species in aquaria, and the Geoffrye Museum in London, which by chance has one of the largest ranges of cichlids and is now sponsored by public bodies. We don’t know yet if any of the cichlid variants in Lake Victoria has hit on a trick to survive even the Nile Perch.
    It’s difficult to know what Nile Perch is about to come in and prune Homo sapiens ’ current diversity. With luck, it will be our own propensity to miscegenation, aided and abetted by airlines, despite the contrary admonitions of our priests. Maybe we’ll all be mixed up into one fairly diverse type. Or maybe it will be Independence Day aliens, out to conquer the galaxy. Or perhaps more competent ones, with elementary virus protection software.
    Were we the Nile Perch for the Neanderthals? What was special about us that they couldn’t compete with? In an editorial in Astounding Science Fact and Fiction , John Campbell Jr proposed that we have been selecting ourselves – in very elvish ways – from earliest times. Campbell credited his idea to the nineteenth-century anthropologist Lewis Morgan, but in truth Campbell contributed most of the story.
    It runs: we select ourselves, through puberty rituals and other tribal rites. To some extent these interact with our religious stories, but as a socialising technique the puberty ritual may have preceded all but the most basic of animistic beliefs. It certainly sits at the base of our Make-a- Homo-sapiens kit. But the Neanderthals may not have possessed such a cultural kit, at least not in the same effective form. If they didn’t, they would probably have been much like Rincewind’s edge people, indeed like all the other great apes: settled and (mostly) contented in their Garden of Eden, but not going anywhere.
    What is so special about puberty rituals? What story makes them a necessary part of how we evolved ourselves into the storytelling animal? Just this, said Campbell: puberty rituals select the breeders. This is the standard mechanism of ‘unnatural selection’ used to breed new varieties of dahlias or dogs, only here it bred new varieties of humans or stabilised existing varieties. The wizards have always known about unnatural selection, and it is reified on Discworld as the God of Evolution in The Last Continent . Unnatural selection is not just a matter of genetics, either. If you don’t get to breed, then you don’t have the opportunity to pass on your cultural prejudices to your children. At best you can try to pass them on to other people’s children.
    Here’s how it works. Over there, we see a group of half a dozen lads, perhaps aged 11 to 14. The older men have prepared an ordeal, and the kids must endure this to become accepted as full members of the tribe: that is, breeders. Perhaps they will be circumcised or otherwise wounded, and the wounds will be ‘dressed’ with painful herbs; perhaps they will be whipped with scorpions or biting insects; perhaps their faces will be seared with red-hot metal brands; perhaps (indeed, usually) the older men will violate them sexually. They will be starved, purged, beaten … oh yes, we are a very inventive species in this regard.
    Those who ran away were not accepted into the group, 5 and so were not breeders. So, in particular, they were not our ancestors, because they weren’t anyone’s ancestors. In contrast, those who submitted to the humiliation were rewarded by acceptance into the tribe. Campbell’s insight was that these puberty rituals selected against the immediate animal avoidance-of-pain response, and selected for both imagination and heroism: ‘If I bear this pain now I will be rewardedby getting the privileges these old men get, and I can imagine that they went through exactly this, and survived.’
    Later on it was the priests who administered the pain. That is how they became the priests, and how successive generations came to