30 Though they're monkeys, not apes.
31 It helps considerably to steal privilege from other species; for instance, all that food material in plant seeds, tubers and bulbs.
32 It happens all the time on Discworld!
33 But we eat sheep, too.
34 There's been a very cute discovery about elephants recently, and the only place we can find to put it is this footnote. (This, after all, is what footnotes are for.) It has been known since 1682 that elephants' lungs are unusual, without the 'pleural cavity', a space between the lungs and the chest wall that is filled with fluid, that most mammals have. Instead of fluid, elephants' lungs are surrounded by loose connective tissue. It now looks as if this type of lung exists because it lets elephants go snorkelling, breathing through their trunks. In 2001 the physiologist John West calculated that with a normal pleural cavity, the pressure of the water would burst the tiny blood vessels in the pleural membrane and snorkelling could be fatal. We're now wondering whether the trunk evolved in the ocean as a snorkel. Land vertebrates first evolved from fish that came up on to the seashore. Much later, a variety of mammals went back into the oceans and evolved into several kinds of sea-mammals, the most spectacular modern descendants being whales. We now see that somewhere along the way, some of those water-adapted mammals came back on to the land and turned into elephants. So the elephant is now on its second evolutionary journey out of the water and on to the land. It would be nice if it made up its mind.
35 See The Science of Discworld, chapter 38.
36 Peasants do cost.
37 David Brin fans will know what we mean here: in the Five Galaxies, no race (save for the long-defunct Progenitors) ever became extelligent without the aid of a sponsor race which already was. Save for humans, because even in an SF story we need to feel superior. We are, after all, the True Human Beings.
38 Always be careful of the twentieth-century 'story' of 'the natives who live in harmony with their environment'. It tends to gloss over the fact that back in history they killed off all the really big animals, and now it's a choice between harmony and death.
39 Mind you, Genesis does say that after Cain killed Abel he was exiled to the land of Nod, on the east of Eden, where he 'knew his wife' and Enoch was born. It doesn't tell us how the wife got to Nod in order to be known. She could have been one of those unmentioned servants, slaves or concubines. That, in turn, raises even more problems with the story of Adam and Eve.
40 This is why we have been forced to invent differences of religious belief, which give us an excuse to kill each other because They are so dramatically different from us True Human Beings -they don't even know that spilling salt, and then failing to hop three time around the table, invites a demon into your home. So it's all right to wipe the False Humans, Them, from the face of the planet.
41 The ! is a symbol denoting a particular clicking sound.
42 A meal that should see you through the week, as the old music hall joke reminds us.
43 Lakes Malawi and Tanganyika still have their cichlid species flocks; your local tropical-fish shop will have representatives.
44 'Going walkabout' seems to have been a way to avoid this torture for at least some Australian tribes.
45 Yes, we know you don't believe this, but ... The first reliable data are in Elliott Philipp's analysis of blood-groups from families in high-rise apartments in Liverpool in the late 1960s, published in 1973. There, 10 per cent of the 'legal paternities' were biologically impossible. So, correcting for the cases where the milkman had the same blood-group as the legal father, about 13—17 per cent were 'discrepant paternities', as the coy phrase goes. Hundreds of births in Maidenhead, in the stockbroker-belt, yielded the same proportions. American figures for the 1980s were about 10 per cent, but these were underestimates because they were not corrected as above. That's the thing about science: it tells you stuff you didn't expect. It gets worse. Or maybe you feel it gets better. At any rate many animals that until recently were famed for their fidelity, such as swans, turn out to be partial to a bit on the side. That ubiquitous beast, the monogamus, is rapidly going extinct.
46 Until we had really good fast computers, and had learned a little bit about how to model the complexity of ecosystems or companies or bacterial communities, most of us practised the reductionist trick of looking for the bits we thought we could understand and modelling those. Then we hoped we could put these separate bits together to understand the whole thing. We were nearly always wrong.
47 As G.K. Chesterton pointed out, fairy tales are certainly not, as modern detractors of the fantasy genre believe, set in a world 'where anything can happen'. They existed in a world with rules ('don't stray from the path', 'don't open the blue door', 'you must be home before midnight', and so on). In a world where anything could happen, you couldn't have stories at all.
48 Admittedly, many African tribes think no such thing: you can hide things from the fairly simple local god. But then it's not much of a god. Probably the tribal mores have been corrupted with the passage of time.
49 Why birth, the sheerest accident during our development? Why not fertilisation? Or hatching from the zonapellucida, the egg membrane? Or the first heartbeat? Or the first dream (while still in the uterus)? Or the first word, or the first carnal experience? There are aspects of our future that are determined by, at least, the date of our birth (we may end up the youngest or the oldest child in the school intake that year, and that can make a big difference) but we're not talking about these human-created things here.
50 The gravitational attraction exerted by a single doctor at a distance of 6 inches is roughly twice that of Jupiter at its closest point to the Earth.
51 At least on Discworld you can see the gods acting disgracefully.
52 Lancre was so backward that its population of 500 had only one civil servant, Shawn Ogg, who handled everything from national defence and tax gathering to mowing the castle lawns, although he was allowed help with the lawns. Lawns required care.
53 There doesn't seem to be a good word for 'to be altruistic'. To altru?
54 In Fisher's day, this simplification was a great idea, because it made it possible to do the sums. Nowadays, it's a bad idea, for the same reason. You can do them, but you can't put any faith in the answers.
55 Altruism, cooperation and love among humans are not the only examples of evolutionary overcommitment ... as the Librarian well knows. A banana is much better suited to being eaten by an orangutan than it needs to be. The rest of the fruit kingdom doesn't come close. What's in it for other fruit, like the tomato, is that its seeds pass through the animal and are dispersed, complete with a built-in packet of fertiliser. A bean-counting tomato could reduce its level of suitability and still ensure that its seeds, rather than those of the competition, were propagated (the juiciest tomatoes used to be from the plants growing at the sewage farm ...). But an over-committed banana avoids the need to test such fine points. By going over the top, losing its seed-producing capacity entirely and relying on humans to propagate it, it ensures that it wins so comfortably that no competitor even gets a look in.
56 ... which can be applied so overpoweringly that the people who aren't Us aren't anything. See the Imperial China parody -the Agatean Empire -in Interesting Times, and a number of Roundworld cultures, too. Being Them is quite a step up by comparison.
57 Other recorded spellings are cience, ciens, scians, scyence, sience, syence, syens, syense, scyense. Oh, and science. Naturally, the wizards have invented another one.
58 So called because it is near the larger island of Kythera. This is 'anti' = near, not 'anti' = opposed to. Though, metaphorically, the two usages are close.