We Won’t Turn Into Crabs

Looking round me again, I saw that, quite near, what I had taken to be a reddish mass of rock was moving slowly towards me. Then I saw the thing was really a monstrous crab-like creature. Can you imagine a crab as large as yonder table, with its many legs moving slowly and uncertainly, its big claws swaying, its long antennæ, like carters’ whips, waving and feeling, and its stalked eyes gleaming at you on either side of its metallic front? Its back was corrugated and ornamented with ungainly bosses, and a greenish incrustation blotched it here and there. I could see the many palps of its complicated mouth flickering and feeling as it moved.

“As I stared at this sinister apparition crawling towards me, I felt a tickling on my cheek as though a fly had lighted there. I tried to brush it away with my hand, but in a moment it returned, and almost immediately came another by my ear. I struck at this, and caught something threadlike. It was drawn swiftly out of my hand. With a frightful qualm, I turned, and I saw that I had grasped the antenna of another monster crab that stood just behind me. Its evil eyes were wriggling on their stalks, its mouth was all alive with appetite, and its vast ungainly claws, smeared with an algal slime, were descending upon me. In a moment my hand was on the lever, and I had placed a month between myself and these monsters. But I was still on the same beach, and I saw them distinctly now as soon as I stopped. Dozens of them seemed to be crawling here and there, in the sombre light, among the foliated sheets of intense green.

• H G Wells, ‘The Time Machine’

TRIGGER WARNING: THE SECOND IMAGE SHOWS A SPIDER, FIVE LINES BELOW THE FIRST.

As Wells’s Time Traveller approaches the end of the world, he stops his time machine and witnesses a cold, almost dead world populated by only a small number of remaining species. There’s the large butterfly-like animal in the sky. There are lichens on the rocks. There is the later tentacled thing in the water. Also, famously, there is the gigantic predatory crab. This is what I want to talk about now. For the purposes of ‘The Time Machine’ at least, H G Wells clearly expected one of the last terrestrial animals living on the surface of this planet to be a giant crab.

In Arthur C Clarke’s 1973 novel ‘Rendezvous With Rama’, which I’m about to spoil, one of the characters crashes his sky bike in an alien habitat to find it being “eaten” by a giant biological robot resembling a crab. So there: crabs again.

Thirdly, on a personal note I once tried to design a terrestrial animal without making any assumptions who could manipulate their/its environment, and found myself coming up with a crab. That is, a squat box of a body with incorporated mouth and sense organs at the front, bilaterally symmetrical with jointed legs and a pair of pincers. I can’t remember the exact reasons why this seemed a good idea at the time, and it would be good to do so because it might explain a certain tendency which has been observed and also exaggerated.

Okay, so there’s this thing called “carcinisation”. It’s been inaccurately described as “every living thing is evolving into a crab”. This is obviously not true. For a start, many living things are evolving into trees instead, and scorpions, pseudoscorpions and lobsters are all suspiciously similar, but there is indeed something about animals called crabs. It’s actually two different things. One is that we tend to use the word “crab” to describe a lot of different animals who are definitely not crabs and the other is that there are a lot of crustaceans who are very crab-like indeed, and their ancestors were often much less crab-like. I’ll start with the first bit.

So, there are horseshoe crabs, crab spiders and crab lice. None of these are crabs and with the possible exception of horseshoe crabs, nobody really thinks they are. This is a horseshoe crab:

^{By Shubham Chatterjee – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=27667459}

I don’t think anyone thinks these are really crabs do they? The main part of their body is not longer than it is wide, is rather flattened and is covered by a chitinous exoskeleton, and they live in salt water and on beaches, so in that sense they’re like crabs, but they’re more closely related to crab spiders than actual crabs, whatever actual crabs are. They’re remarkable in all sorts of ways, but also remarkably, I’m not going to digress about them here.

Speaking of crab spiders:

. . .that’s what this is. These live in flowers awaiting insects landing on them such as bees, and they’re unusual for British land animals because they can change colour to camouflage themselves against their backgrounds. They look a lot more like crabs than their relatives. By “crab”, I mean the classic flat and wide bodied decapods with claws.

Then there are these delightful individuals:

^{By Doc. RNDr. Josef Reischig, CSc. – Author’s archive, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31557499}

It’s unfair to judge parasites for their life styles. Nobody ever asks to be an obligate parasite as far as I know. Then again, we presumably have our own instinctive revulsion of organisms, which we can’t really help either. Actually we can, but it can be difficult. I used to be a koumpounophobe, so I do realise people can’t do anything about this stuff unless a miracle occurs (which it did for me). I mean, you can have therapy I suppose. These are of course insects and there are only two species of them, whose other lives on gorillas. This makes me wonder why it’s just them and us. They can also live on eyelashes, particularly children’s, and that’s a whole rabbit hole I’m not going to talk about. Presumably they’re that shape because it makes them harder to catch, and like head and body lice they’re dorsolaterally compressed, and I think they cling on with their front legs. And they’re not crabs.

Seeing as I’ve mentioned crab spiders, I may as well mention spider crabs. I won’t be showing a picture of them because of arachnophobes who might be reading this, but they’re not spiders but crabs. Or are they? This brings up the whole issue of what a crab is. This is yer bog standard crab:

_{Hans Hillewaert Description Cancer pagurus Linnaeus, 1758 English: Edible crab form the Belgian part of the North Sea. Date 6 March 2006 Source Own work}

Now this is definitely a crab. As the caption says, they’re Cancer pagurus, the so-called “edible crab”. I don’t know about you, but I’d be a little disturbed if some Dannelian decided to call me an example of an “edible human”, and it seems a bit unfair to define their identity in this way. In a way of course, they do crawl around being edible, but then many other animals do, not always by humans but by some other species. Also, we don’t call sheep “edible sheep”, and other species of crab can be eaten, so why?

Anyway. . .

This is a crab, that much is for sure, and there are other species of crab related to them who are presumably also crabs, such as the swimming crab:

^{By Didier Descouens – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=8404985}

This is also definitely a crab, whose back legs are specialised for swimming, and I’d be gobsmacked if this species turned out not to be closely related to the previous one. This makes me wonder how much crabs who are not crabs resemble crabs who are. Nonetheless, there is this thing called carcinisation.

The issue was first raised formally in 1916 by the zoölogist Lancelot Alexander Borradaile, who referred to it as:

… the phenomenon which may be called “carcinization” … consists essentially in a reduction of the abdomen of a macrurous crustacean, together with a depression and broadening of its cephalothorax, so that the animal assumes the general habit of body of a crab

• British Antarctic (“Terra Nova”) Expedition, 1910–1913. Natural History Report. Zoology. 3 (3). British Museum: 111–126.

What he meant by this was that many crustaceans evolve in the direction of having a carapace wider than its length, the belly side is fused into a kind of breastplate similar to that of a tortoise, turtle or terrapin, and the rear portion is flattened and bent over, completely invisible from above. The crucial feature distinguishing true crabs from merely carcinised crustaceans is that the latter only have six walking legs. Hence the porcelain crabs, for instance, are not true crabs:

^{By J. Antonio Baeza – Baeza, J. Antonio (10 March 2016). “Molecular phylogeny of porcelain crabs (Porcellanidae: Petrolisthes and allies) from the south eastern Pacific: the genera Allopetrolisthes and Liopetrolisthes are not natural entities”. PeerJ 4: e1805. DOI:10.7717/peerj.1805., CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=47470579}

These have three pairs of legs plus claws at the front, so they presumably started off with four pairs and the front pair became claws. In fact, one particular porcelain crab is said to be “hypercarcinised” in that they are not only crab-like but the males have a smaller pleon (the bent-forward underside bit) than the females, which is also the case for true crabs. This is the crab in question:

^{By J. Antonio Baeza – This file has been extracted from another file, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=47628248}

Crabs have apparently evolved five times, or rather the crabs who are still around today are of five only distantly related lines. There are the hermit crabs, who are distinctive in being asymmetrical and gave rise to the coconut crabs:

These are the largest land-living arthropods of all, weighing four kilogrammes and are almost a metre across with their legs spread out, and they don’t spend much time in the water at all. Adults actually drown in water, so their arrangement is like amphibians, with larval forms in the water crawling onto the land to become adults. Their affinity to hermit crabs can be discerned through their relatives the king crabs, who are still asymmetrical, which hermit crabs need to be so they can fit themselves into whelk shells. And of course hermit crabs are not crabs. Along with porcelain crabs, they belong to the order anomura rather than the true crab order brachyura. They’re related to squat lobsters:

^{By Matthias Buschmann (M.Buschmann) – Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=1729257}

Hermit crabs might be described as needing to live in shells (they also live in rubbish like bottle caps) because their exoskeletons are too soft, but it also makes sense to say they save themselves the bother of growing hard carapaces by using shells instead. Some other animal builds the armour, dies and they then recycle it.

A further, related example is the king crab:

^{By The Children’s Museum of Indianapolis, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17133782}

Hairy stone crabs are yet another example:

^{By Michael Marmach – https://collections.museumsvictoria.com.au/species/8663, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=137332771}

Although all the other examples given so far are crustaceans in the infraorder anomura, whereas true crabs are brachyura, that’s not an order exclusively of crabs and their ancestors weren’t crab-like. There’s a further, long-extinct, example, consisting of an entire order, the cyclida, living from the Carboniferous into probably late on in the age of (non-avian) dinosaurs, who looked like this:

^{By Hemiauchenia – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=127979567}

Palaeontologists disagree about what cyclids were. Although they’re usually considered crustaceans, a minority believe they were chelicerates, i.e. related to spiders and horseshoe crabs. If so, it’s all the more remarkable that they’re like crabs.

To a limited extent, turtles are somewhat crab-like, although since they lack the general body plan of arthropods they aren’t that similar. All of the crab-like animals mentioned here are arthropods. Crab lice and crab spiders are apparently merely coincidentally crab-like, as they live out of the water.

What, then, are the pressures that tend to make decapod crustaceans into crabs? Well, the living examples are all decapods, which incidentally seems to specialise in convergent evolution as it also includes the scorpion-like lobsters and crayfish, so they have somewhat similar genes which may mutate in the same direction. The intermediate forms are usually like squat lobsters. Although none of their ancestors were similar to crabs, they were in fact similar to each other. The ancestor of the true crabs was also, unsurprisingly, not particularly crab-like:

^{By Gerhard Scholtz – Eocarcinus praecursor Withers, 1932 (Malacostraca, Decapoda, Meiura) is a stem group brachyuran Arthropod Structure & Development, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=97615916}

This, Eocarcinus, was early Jurassic and once again somewhat squat lobster-like. I don’t know how much cyclids and early brachyura overlapped, but I suppose it’s possible that the latter were “new and improved” and edged the others out, presumably sideways.

There are other factors. Their relatives flex their hind ends to escape rapidly but because crabs’ are bent under, this is no longer possible and they have to run instead. This is also true of coconut crabs because they live on land, so they don’t have the advantage of pushing themselves around in water.

All this, of course, is an example of convergent evolution, although in fairly closely related animals who already have the genetic precursors and appropriate environment to help them do so. To clear up the big myths, this is not an unusual process and not everyone is turning into a crab. Humans have lost their tails, are dorsoventrally flattened and have grabbing hands, but we’re not becoming any more crab-like than that and apart from the opposable thumbs, these are not to do with the pressures on crabs to go that way. Even so, it’s conceivable that because this process also leads to front claws that can manipulate objects and is encouraged by living out of the water, other intelligent life forms in the Universe might actually look like crabs, which explains the Macra on Doctor Who.

To me, there is a much more spectacular example of convergent evolution in the form of pitcher plants. We have for a few years now had Nepenthes pitcher plants growing in our utility room:

A while back, I also tried to grow Sarracenia but it died:

These are trumpet pitchers and are in the same order as heather. They mainly grow in Canada, which is why I thought they’d be fine here in England, but actually they died, possibly because I accidentally chose a species native to subtropical North America instead. The Nepenthes, though, have thriven. These are Old World tropical plants in a huge order including cacti, chickweeds and soapwort, although there are so many of them that this is a pretty arbitrary choice of examples. A third lot of pitcher plants is in the bromeliad family along with pineapples and papaya, including tank bromeliads, which are quite amazing. They have a whorl of leaves, really blades as they’re related to grasses, in whose centre rainwater collects and into which, like the others, insects fall and are digested. Unlike the other pitcher plants, though, tank bromeliads have entire ecosystems living in the water too, including frogs and salamanders. One example of a tank bromeliad is Brocchinia reducta, one of three carnivorous species of the plants:

^{By Christian Hummert – http://de.wikipedia.org/wiki/Bild:Broccinia_(reducta)???_2.jpg, CC BY-SA 2.0 de, https://commons.wikimedia.org/w/index.php?curid=1517361}

It’s fairly easy to understand how a bromeliad could become carnivorous. Pineapples and papaya both contain enzymes which break down protein (proteases). Pineapples also have a whorl of leaves at the top which would collect rainwater. In a tropical environment, leaf litter and also dead insects are likely to fall into this water, and in the latter case drown. From this, it’s a small step to them eating insects, using them the way other plants use leaf litter and decaying animal life to fertilise their roots. Incidentally, in a side note, it’s also easy to see an affinity between pineapples and sweetcorn cobs.

A further example is Cephalotus follicularis, the Australian pitcher plant:

^{By H. Zell – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=56478465}

Once again, the same thing has happened and this time the plant is a lot more like Nepenthes, but again is not closely related to any of the others. Thisses family contains just this single species, but they’re related to wood sorrel and a number of other plants more familiar to Europeans.

Apparently this has happened eleven times. In the case of Nepenthes, two species have symbiotic relationships, one with treeshrews and another with bats. The bats roost inside the pitchers and poo into them, and the treeshrews use them as toilets, in both cases providing nitrogen. Pitcher plants sometimes appear to be related to flypaper trap plants such as sundew, which operate by having sticky leaves which trap insects, and may either be evolving into pitcher plants or have evolved from them. Again, this has happened several times in unrelated lineages.

There are many other examples. Koalas, for instance, have fingerprints indistinguishable from ours and also opposable thumbs, although in their case both the first and second digits are involved. That occurs in humans sometimes in a condition known as Robinow Syndrome, which I don’t actually consider to be a valid syndrome so much as an individual variant. There’s also the very obvious ichthyosaur/dolphin/sawfish business.

So carcinisation, though interesting, certainly doesn’t mean everyone will eventually turn into a crab. Some carcinised species have also become less crab-like over time. For some reason, people have latched onto it and turned it into a seemingly bigger thing than it really is. It’s interesting, and it’s a good example of convergent evolution, but I very much doubt that any of my descendants will ever be living on a beach with a carapace and claws.

DNA – Douglas Noel Adams and Deoxyribonucleic Acid

I’ve recently had a kind of brainworm I had to get down on paper, or rather on screen as it is nowadays, though it needn’t be. It focusses on ‘The Hitch-Hiker’s Guide To The Galaxy’ and I have of course spent way too much time concentrating on this to the detriment of the work itself, but I can’t resist it. On this occasion though, it yielded fruit, almost literally in fact, and turned out to culminate in something which was a lot less ridiculous than I initially thought. The problem was that despite it not being particularly pointful, I couldn’t get it out of my head.

The ultimate question, so to speak, is this:

How many species of organism could be rescued from Earth after it gets demolished by the Vogons?

This thought originated from the scene in Fit The First where Ford and Arthur are hiding on the Vogon spaceship, having just beamed aboard, and after a suitable pause, Ford tells Arthur, “I brought some peanuts.” When I heard this line, I felt a sense of poignancy that not only had the world just ended, but apparently the only other species of Earth life than humans which persisted, the peanut, would shortly itself be destroyed by Arthur’s digestive juices, and then that would be it: nothing would remain other than Arthur, as far as the listener knows at the time. Further consideration, and further listening, would demonstrate that this was not in fact so. And so begins the highly elaborate glass bead game.

There are, considering the entire trilogy of five books, several categories of life originating on this planet involved. It breaks down thus, and I am going to number the categories because they are quite enlightening:

1. Trillian and Arthur themselves. Humans survived the destruction of the planet.
2. Organisms whose DNA or other biological traces are on or in Arthur, or stand a chance of being associated with him.
3. The same issue considering Trillian. It may seem arbitrary to cleave the two humans in this way, but it turns out to be anything but. I’ll come back to this.
4. Other organisms who left Earth before or during its destruction, either canonically or plausibly without evoking the canon.
5. Earth organisms who canonically sprung into being due to the operation of the Infinite Improbability Drive.
6. Organisms accidentally removed in other ways.
7. Organisms mentioned which appear to be from Earth but in fact are not.

I’m going to consider these in reverse order.

Organisms Only Apparently From Earth

Items are mentioned here and there whose origin appears to be terrestrial but is apparently not. For instance, Ford asks the Vogon guard whether the appeal of his job is wearing rubber. Rubber could be considered as originating only from a specific tree originating in Brazil, Hevea brasiliensis, the rubber tree. However, two facts argue against this. One is that latex from other plants can and has been used to make rubber, for instance dandelions. The other is that synthetic rubbers exist and the word could be used less strictly, and may well be. For instance, there is silicone rubber. Hence rubber itself probably shouldn’t be taken to indicate that there are rubber trees of that species elsewhere in the Universe.

This is in fact kind of acknowledged in the books, with the existence of jynnan tonix and ouisghiansodas. Many civilisations throughout the Galaxy have a drink called something like “gin and tonic”, although beyond the name they don’t resemble each other, and it also turns out that there’s another similar coincidence, undiscovered and unacknowledged, in the form of “whisky and soda”. Given this, it’s possible that the various items referred to are not identical to an Earth reader’s concept of those things. They may in fact be almost but not entirely like them. The obvious answer here is tea, as produced by the Nutrimat Machine. It isn’t clear where this originates. Tea is available from the local megamart in a variety of easy to swallow capsules, and the initial creation of the Infinite Improbability Drive required a cup of really hot tea. It isn’t clear why, because hot water might be thought to suffice. Arthur is also made the best tea he’s ever tasted at one point on the Heart Of Gold. Hence for some reason, tea appears to exist, or to have existed in the past, elsewhere in the Universe. However, like rubber the word “tea” has a more generic meaning, referring to any vegetable matter infused in hot water, such as chamomile tea or rooibosch. Even so, Arthur clearly perceives the tea as tea. Two things may have happened here. Either literal Camellia sinensis exists on other worlds or it was obtained from Earth. There is a third possibility which will be considered later.

One fruit is mentioned at least thrice. The Pan-Galactic Gargle Blaster is described as having one’s brains smashed out by a slice of lemon wrapped around a large gold brick. When Ford and Arthur arrive on the ‘B’ Ark, the security guard offers them a lemon with their jynnan tonix. Finally, on Brontitall, the starship is delayed nine hundred years while waiting for lemon-soaked paper napkins. This is quite a striking recurrence. It’s possible that the lemon arrived with the Golgafrinchams on the ‘B’ Ark, but perhaps interestingly the scent of lemon is quite widely distributed through plants on this planet, such as lemon grass and lemon verbena. It’s one of two enantiomers of limonene, the other being the scent of oranges. There are also other lemon-flavoured organisms, such as black ants. The presence of citric acid in an organic life form would probably not be unusual. For whatever reason, something lemony is out there among the stars. Perhaps even a lemon.

Potatoes seem to be another such organism. These are very ancient. The Silastic Armourfiends were ordered to punch bags of potatoes to vent their aggression many millions of years before the manufacture of Earth and therefore the appearance of potatoes as we know them. Again, this could be a generic reference to tuberous root vegetables. Even on Earth we have starchy root crops similar to potatoes, such as sweet potatoes.

A further species, possibly several, crops up in Deep Thought’s original deduction of a recipe for rice pudding. This includes rice, milk, cream and cinnamon in the TV version. The existence of rice is not controversial. It means that rice pudding existed at that point in time. To digress slightly, it’s difficult to know how to refer to deep time in H2G2 because in its universe Earth didn’t exist before a few million years ago, so it’s not sensible to use the conjectured geological time periods such as “Jurassic” before the planet was built. The only real epochs are the Pliocene, Pleistocene and Holocene, the only real era is the Cenozoic, and not all of that. The question regarding Deep Thought here, though, is whether it anticipated the existence of rice pudding or deduced its current presence in the Universe. If it did the former, there’s an issue with why it couldn’t simply use its anticipation of the future course of Earth history to give the mice the Ultimate Question, so it makes more sense to see it as already in existence. The existence of milk in this recipe is pretty unproblematic, as milk is just what we call opaque white potable liquids such as coconut milk, and sometimes even impotable ones such as dandelion milk. Cinnamon, however, is highly specific.

It’s possible to extract a principle from this: there are generic items in the wider Universe which have surprisingly specific resemblances to familiar terrestrial ones. Out there in the Galaxy there is milk and rubber, perhaps unsurprisingly, but also tea, potatoes, lemon and even cinnamon. Incidentally, I have to get this out of my head: the spice Melange from Frank Herbert’s ‘Dune’ series has similarities to cinnamon according to the now-banned Dune Encyclopedia, so it isn’t just H2G2 which anticipates the existence of interstellar cinnamon (brand new sentence there). There are two other aspects to this. In an infinite Universe, everything is possible according to the Guide, so for example the Babel fish and ratchet screwdriver trees exist, as do sentient mattresses. Just on the last issue, it is kind of true even on Earth that living mattresses and lilos are possible as they did before the evolution of life as we know it since the Cambrian. This means that every species found on Earth does in fact exist somewhere else in the Universe, and in fact that a carbon copy of Earth exists which was not built by the Magratheans. Maybe we’re on that Earth and Arthur Dent’s an alien. The other aspect is that Deep Thought could have designed Earth as a microcosm of the wider Galaxy with organisms resembling those from elsewhere, so it isn’t that there are coincidentally or by convergence life forms elsewhere so much as that they were deliberately put here.

Organisms Accidentally Removed in Various Ways

The main mechanism here is teasers, or as we call them, little green men. These are occupants of interstellar craft who visit Earth and other planets and pretend to be stereotypical aliens. They are presumably also abductors, creators of crop circles, and interfere with cattle. I’m going to assume that the most contact they have with organisms on Earth is in the form of trampling on crop circles, which I also assume they make in the same way as the hoaxers do. Incidentally, although crop circles and UFOs were not widely associated by the public until something like 1990, the association did exist back in the ’70s but was only made in flying saucer enthusiast circles, so to speak. This is of course leading up to the “fact” that teasers take wheat pollen with them when they leave – Triticum aestivum. There’s another aspect to their visit which I will consider under another heading as it’s best considered with Trillian and particularly Arthur.

When the Earth explodes, various particularly tough organisms such as extremophiles might survive in the ensuing cloud of débris. Tardigrades are the obvious example, as they can survive dormant in space, possibly for years. There may even be tardigrades on Mars, and there definitely are on Cynthia (“the Moon”). Another category of organisms this clearly applies to is certain archaeans. Archaeans are microörganisms once confused with bacteria, many of which can survive in extreme conditions such as hot springs. These could possibly survive too, again perhaps in a dormant state.

Zaphod Beeblebrox also visited Earth and took one organism, Trillian, with him deliberately, but probably also took others accidentally. I’ll go into this in greater depth when I consider Trillian.

Finally, Arthur finds an unexpected bottle of retsina:

Vitis vinifera – grape. Used in the retsina Arthur finds on Agrajag’s planet.

Pinus halepensis – Aleppo pine, whose resin is an ingredient of retsina.

Saccharomyces cerevisiae – Brewer’s yeast, found in the retsina.

Infinite Improbability Drive Creations

Several organisms are created when the Infinite Improbability Drive is operated. There are very obvious examples, but I’ll deal with them in order of the timelike curve described by the Heart Of Gold.

The first time the drive is operated, it causes two hundred and thirty-nine thousand fried eggs to appear on the planet Poghril, where all but one person had just died of starvation. This seems at first to imply that it brought Gallus domesticus into existence, but actually it doesn’t. Eggs are a common means of reproduction found throughout the metazoan clade, such as with slugs, spiders and birds. These particular eggs must resemble hen’s to some extent because they seem to contain albumen and yolks and are altered by frying in a familiar way. At no point did they have shells, incidentally, as they were yanked into being without them. They are also high in cholesterol. Even so, I don’t believe these have to be hen’s eggs.

Now for the two most prominent incidents. When Ford and Arthur are rescued, they meet several species of animal on the Heart Of Gold and Ford turns into a penguin. I’m not sure whether to count that because he’s only temporarily transformed. There’s also a five-headed person crawling up a wall, but there are no such organisms on Earth. What there is, however, is an infinite number of monkeys, apparently capuchins. It isn’t clear what happens to any of these species but they don’t seem to be in evidence once normality is restored. That’s not true, though, of the sperm whale and the bowl of petunias. This next bit, therefore, is easy: Petunia and Physeter catadon. There’s even flesh strewn around on Magrathea afterwards. Although it’s straightforward that these species are brought into existence, it’s not so clear that they were alone. The sperm whale could, for all we know, be encrusted with barnacles and contain typical gut flora for a sperm whale along with parasites such as a tapeworm, but the simplest assumption is that the sperm whale is isolated. It’s also fair to question which organisms if any co-occurred with the Petunia, since it is in a bowl and therefore potted in some material. However, again we don’t know that this is so.

Just a side-issue on this: there was at one point going to be a goat on the Heart of Gold after Arthur rescued everyone from the missiles, but this was not pursued. On other occasions, there was a fossilised towel, but nothing is recorded to have happened in that respect when it was operated to escape from the Vogons or visit the Man In The Shack.

There is a flaw in how I’ve considered this. In fact, any terrestrial species could be conjured into existence by the Infinite Improbability Drive, but not in the narrative of the actual stories.

Trillian

Trillian is the most interesting aspect of this entire issue, and in fact she’s why I decided this wasn’t just a frivolous mind game. There is a markèd contrast between Arthur’s and Trillian’s biomes due to the circumstances of their departure and gender, which could in any case be linked.

Trillian was at a party six months before Earth’s destruction. She was surrounded by various alcoholic beverages and snacks. This contributes to her status as a goldmine of genomes, as does her gender presentation. Unlike Arthur she’s likely to have cosmetics, scent and jewellery, as well as residues of toiletries. She was being chatted up by Arthur, then Zaphod, as “Phil”, came along and, well, abducted her right out of that environment, which was not the moribund ecosystem surrounding Arthur as it was being destroyed, but a still-thriving habitat. Many organisms are likely to be held in common between them such as Candida albicans, which is found in the human gut, and in fact many of the microörganisms in their digestive tracts, lungs and body surfaces. Both have, for example, follicle mites – Demodex follicularum. They may also have pathogens, such as rhinovirus, and at a pinch even the likes of fleas and head lice, though probably not. Both have Mentha x piperita – peppermint – in their mouths, or possibly spearmint, from toothpaste.

Here’s a breakdown of what she might distinctively have on her and why:

From cocktails:

Cinchona pubescens – quinine, in bitter lemon.

Juniperus communis – juniper, in gin.

Olea europaea – olive, on cocktail sticks. This is, however, also mentioned in connection with Pan-Galactic Gargle Blasters, so it doesn’t count as distinctively terrestrial.

Prunus avium – cherry, also on cocktail stick.

Curcuma longa – cucumber. This is a long shot but not only might this occur in a cocktail but also in a cucumber sandwich. That also means:

Lepidum sativum – cress.

Sinapis alba – white mustard.

(Mustard and cress sandwiches)

Possibly an Abies species for the cocktail stick, but more likely to be Pinus, which was already in the retsina.

Artemisia absinthium – wormwood, if they had absinthe.

Gallus domesticus – hen, if there was advocaat (eggs).

Vanilla planifolia – vanilla orchid, same source.

Citrus aurantium – orange.

Pyrus malus – apple.

Angostura trifoliata – if they had genuine angostura bitters.

Solanum lycopersicum – tomato.

There would also have been snacks, which might allow various nut species to be recovered, such as Anacardium officinale (cashews), Prunus amygdalus (almond) and others. There could also be other things such as trail mix, pork scratchings or Bombay mix, but it would rely on Trillian actually eating it, and having the drinks.

Canapes might contain:

Salmo salar – salmon

Thunnus tynnus – Atlantic bluefin tuna

Allium sativa – garlic

Again, she’d have to eat or at least touch these. Both these categories are very uncertain, and in fact I can add a couple of quite likely ones:

Ananas comosus – pineapple. There are pretty sure to be pineapple cubes on sticks at this party.

Prawn cocktail – it isn’t clear to me which species of decapod is most popular as food.

Much of the above is culturally and historically specific. Wealthier people would have different food available. Trillian is not wealthy, but on the dole, although she may have had social capital from university days or others. Later on, something like sambuca might have become available, meaning licorice, possibly elder (Sambucus nigra). There is a positive wealth of possible organisms here, but also a high degree of uncertainty.

Cosmetics: Many cosmetics are mineral-based. Their ingredients also change over time, trending at the moment towards plant sources.

Lipstick:

Ricinus communis – Castor oil plant.

Theobroma cacao – cacao. Cocoa butter.

Simmondsia chinensis – Jojoba (also possibly in shampoo and conditioner).

Copernica conifera – Carnauba wax. Could also be on lemon rind.

Dactylopius coccus – cochineal insect. Could also be present in food.

Kerria lacca – lac bug. Possibly in makeup or on lemon rind, might also be on nail varnish.

These last two are likely to be less common today.

Eye shadow: exclusively mineral ingredients.

Mascara: big overlap with lipstick.

Foundation: palmitic acid, which remarkably at this stage (1978) could have been from sperm whale again!

Various glycerol-based lipids from a variety of different sources.

Primer: again remarkably, this could in theory be a source of Thea sinensis or Vitis, but I reckon that’s too sophisticated for the ’70s. Another change.

Blusher:

Cetorhinus maximus – basking shark, source of squalene. Could be a couple of other species. Nowadays this is not from animals, but back then it was. There are other species of shark this could be from.

Shampoo:

Cocos nucifera – coconut palm. TBH, this is probably going to be in something on the above lists anyway.

Elaeis guineensis – oil palm. This doesn’t really belong here but there will be palm oil in something.

Conditioner:

Sorbitol occurs naturally in various fruits.

Perfume and scent ingredients derived from various plants, e.g.

Lavandula angustifolia – lavender

Rosmarinus officinalis – rosemary

Rosa sp – there are so many species of rose it’s ridiculous, so I’m not going to narrow it down further than that.

Jasminum officinale – jasmine.

Pogostemon cablin – patchouli (less likely).

It’s uncertain whether these are just various compounds from the relevant organisms or if their actual genomes would be available. It’s also notable that Trillian has a less detailed back story than Arthur, and some of the uncertainty may result from that. This, sadly, probably arises from Douglas Adams’s sexism. His female characters generally seem to be less filled-out than his male ones. Most of his cybernetic characters are also male, with the exception of the Nutrimatic machine. The type of character Trillian has been made to become is, to be fair, not enormously stereotypical because she’s an astrophysicist, but her presentation is typically feminine, hence the massive biological accoutrements. This could be flipped: why isn’t Arthur expected to make this effort? It’s still interesting that if you remove an average woman from 1970s Islington from Earth, you sample a lot more of the planet’s biosphere with her than if you remove an average man from the rural West Country, even though she’s in an urban environment and he’s in a rural one.

Arthur’s turn. Arthur is a six-foot tall ape descendant (nowadays he’s seen as an ape) who works in local radio, and is of course a man. Here’s a list of what he has on or in him at the end of the world:

Felis cattus – domestic cat. When Arthur arrives back on Earth, there is a dead cat in his house, so he may have had a cat. Some fur may exist on his dressing gown. In fact it almost certainly does, and also aerosols from the cat licking her fur. 

At this point I should probably mention an organism of ‘Trainspotting’ fame: Toxoplasma gondii. Arthur may well actually be subclinically infected by Toxoplasma, as many people associated with cats are.

Canis familiaris – dog. As Arthur is about to be thrown off the Vogon spaceship, he says he was planning to “brush the dog”, so there may also be dog hairs on his dressing gown. Also, possibly Know-Nothing may have done the same, though this is less likely. In case you don’t know, Know-Nothing is the pub dog in Cottington, Arthur’s village.

Right at the start of the narrative portion of the story, Arthur’s morning routine is described.

Bos taurus – cattle. Arthur makes himself a cup of coffee just before he notices the bulldozers outside. The milk he puts in it probably has cow DNA in it.

Coffea robusta – coffee. Since it’s the ’80s, Arthur probably uses instant coffee, hence robusta rather than arabica.

Toothpaste occurs around this stage. There’s also shaving foam, which may contain Gossypium among other ingredients, and there might even be aftershave although this isn’t mentioned.

Humulus lupulus – hops in the six pints of beer Ford buys Arthur at lunchtime.

Hordeum vulgare – barley used to make the beer.

Saccharomyces cerevisiae – the yeast fermenting the beer and the retsina on Agrajag’s planet, which I’ve mentioned.

Arachis hypogaea – peanuts. “I brought some peanuts” – Ford’s comment which started this whole futile enterprise.

Musca domestica – house fly. Arthur swats flies on prehistoric Earth, possibly not that species but at least one species of fly. This is also Agrajag.

Oryctolagus cuniculus – the rabbit Arthur killed to make his bag out of. Also Agrajag.

Ovis aries – sheep. Wool in dressing gown.

Tineola bisselliella – clothes moth. Possible but unlikely.

Gossypium arboreum – cotton, probably present somewhere on Arthur’s person.

Morus alba – again, possible but unlikely. The white mulberry on which the silk worms making any silk Arthur might be wearing fed.

Bombyx mori – silk worm/moth. Could be present in Arthur’s clothing

Hevea brasiliensis – rubber tree. Might be present in Arthur’s slippers.

Saccharum sp – sugar cane. Unlikely, but he might’ve had sugar in his coffee and that might not have been refined.

Beta vulgaria – sugar beet. Mutually exclusive with the previous species. Also, I’m not convinced white sugar still contains any trace of DNA.

Commensal organisms:

Demodex folliculorum – follicle mite in Arthur’s eyelashes.

Candida albicans – thrush yeast. Present in the gastrointestinal tract of about half of human adults.

Gut flora – a large number of species.

Dermatophagoides pteronyssinus – house dust mite. According to the Infocom game, Arthur has fluff in his pocket, which probably contains this animal. Incidentally, this is the European dust mite. The American dust mite would not have survived in all probability.

Hence Trillian could be associated with thirty-seven named species whereas Arthur, despite the fact that we know a lot more about his circumstances as he left Earth, only has twenty-five. Two of them result from his personal violence against animals.

Arthur may not be wearing make up, but he is wearing mud. He lay down in front of the bulldozer. This means he’s likely to be covered in it, leading to such soil organisms as Caenorhabditis elegans and Colpoda, as well as various fungi.

Ford and Arthur are also covered in pollen. This would vary according to the time of year. Perhaps surprisingly, there are only two short date ranges during which the destruction of the Earth could have occurred. We know from the TV series that the Sun rose at 6:30 am on that day. Due to leap years, the date when this happens moves around slightly and due to BST it might be an hour earlier. We also know it’s a Thursday, although this has been disputed because of the football reference. Assuming it’s 1978, the relevant dates are 6th August (Hiroshima Day, rather appropriately), 3rd May and 4th April, none of which are on Thursday. Considering it’s the Vogons, I like the idea that it’s the last day of the tax year, 5th April. If this is so, likely pollens include alder, elm, willow, birch, ash, and, perhaps surprisingly, rather few herbs. Hence the rather obvious privet hedge buffeted by the wind just before Ford activates the electronic thumb is not shedding pollen and hence would only survive if one of its leaves got lodged in Arthur’s dressing gown or PJ’s. Some other plants would already be shedding but not at their peak, including plane, oak and canola.

Other Organisms Leaving Earth Voluntarily

There are two other types of animal who left Earth or were unaffected by its destruction. One of these was the dolphin. It isn’t clear whether this means all dolphins or a limited or unique species. I’ve assumed it was Tursiops truncatus, the bottlenose dolphin. They left Earth shortly before the Vogons arrived, having failed to be communicate the warning although I’m not sure what we could’ve done to prevent it really. They may have taken a food supply with them or simply had half-digested fish in their digestive systems, so that would include herring, mackerel and possibly krill. Other species include mullet, cephalopods, conger eels, hake, bandfish (in this case I didn’t know those existed in the first place) and porgies. Regarding internal parasites, there’s Cryptosporidium, a protist, Ascaris, a nematode, Giardia, another protist and Nasitrema, a trematode, but the question arises of whether the dolphins would use the opportunity to rid themselves of these or perhaps recognise their role in their health, as they might reduce the prevalence of autoimmune conditions. Whale lice would also be present if they chose to keep them. Just as humans are covered in pollen, dolphins and their prey are covered in phytoplankton, such as diatoms. Hence various single-celled algae can be expected to be salvageable.

The final category appears to be mice and the organisms associated with them. Again, it isn’t clear whether it’s just Mus musculus or several species of mice involved. I’m going to assume the former, but note also that whatever the original mouse was, they had time to evolve. What we think of as mice are of course merely the three-dimensional projections of hyperintelligent pan-dimensional beings, and being mice is just the day job.  Nonetheless, Trillian took her mice with her and can therefore be presumed to have taken their food. Mice are of course omnivorous, like most or all rodents, but are sometimes assumed to be herbivorous. In 1978, mice were fed a mixture of seeds and pellets of some kind which I couldn’t identify but may have been minced up insects or something. The seeds included sunflower, split peas, lentils and presumably peanuts. Mice get parasites like dolphins and humans but it’s unlikely Trillian’s would have any. It’s hard to know whether to count mice as native to Earth in the H2G2 universe, as they aren’t what we think they are.

Several issues remain. One is that Earth being only ten million years ago, all the fossils and evolution presumed to happen up until that point are fake, but after that point are probably real. I say fake evolution because DNA analysis would still show an apparent genetic relationship between, for example, humans and chimps even though chimps are native to this planet and humans are not, or between undoubtedly native organisms which were in fact separate creations or not even from the same planet or even dimension in one case. And this is the really weird thing about this whole constructed Earth scenario: Douglas Adams was clearly “a great fan of science” but his version of Earth is almost creationist, though not exactly young Earth creationist. The arrival of the Golgafrinchams led to the replacement of hominins by alien humans, since humans are aliens, and also possibly the introduction of novel species such as grapes, olives and lemons, and maybe also various other species which also replaced their native counterparts or successfully competed with species in similar ecological niches. Despite all this, all known life on Earth is now established to be related. Is this perhaps because it isn’t just life here which is related, but across the Galaxy? Did panspermia happen? Is it happening all the time? Or did the computer program which ran the Earth have to simulate the wider Universe in order to provide the right data on which to base its calculations? This could mean that Earth simply encapsulates the biomes of the wider Galaxy. Maybe life is just constantly diffusing in and out of Earth’s biosphere and linked genetically to the rest of the Universe.

To conclude, I think this is a good way of illustrating the intentional fallacy. Arthur’s and Trillian’s biomes are quite different from each other, although they overlap. Although Douglas Adams is unlikely to have any conscious intention of writing Arthur as a fuller character than Trillian, if he had written them more equally, Trillian’s biome would have been as certain as Arthur’s. This is in spite of the fact that Arthur is supposed to be “Everyman”, i.e. a close to blank slate, though quintessentially English, in whose position the reader is supposed to place herself. Trillian absconded from Earth in its prime, and because her gender stereotype is more clearly constructed than Arthur’s, she takes more of the planet with her when she goes. It’s expensive being a “girl”, meaning that whereas it’s alleged to be optional to present oneself as feminine as a woman, in many contexts this will place one at a disadvantage or put one in danger. Adams is also sketchier about Trillian’s background because he’s writing about what he knows, and he doesn’t know women in the same way as women know women. Moreover, Trillian leaves Earth willingly whereas Arthur has to be prised away from it even though he’ll die otherwise, which somehow reminds me of “women get sick but men die”. On the other hand, Trillian may be too compliant for comfort.

A few more things can be drawn out of this:

• H2G2 is oddly “creationist”, but “middle-aged Earth Creationist” rather than young or old Earth, despite Douglas Adams being proselytisingly atheist. This is also similar to Terry Pratchett’s ‘Strata’.
• Recent developments in DNA sequencing would be expected to have revealed that there was more than one line of evolution leading to organisms on this planet. Larry Niven did something similar with the Protectors.
• Terms used for certain items in the H2G2 universe are known to have wider references than they are usually used. This is acknowledged in the case of jynnan tonix and implied with ouisgiansoda, but may be much wider than is at first apparent. For instance, it may include “rubber”, “lemon” and “milk”.
• As the H2G2 universe is infinite, there are countably infinitely many identical species to those found on Earth in any case. This too is suggested in the text with the ratchet screwdriver trees, mattresses and the Babel fish.
• What would a gender-swapped version of H2G2 be like? What would this version be like told from Trillian’s perspective? Would gender-swapping include Marvin, Eddie and the Nutrimatic Machine?

Fool’s Tigers

Aristotle is infamously wrong about stuff. He thought heavier objects fell faster than light ones, that objects had a tendency to grind to a halt without constant application of force and that matter did not consist of atoms but was infinitely divisible. These mistakes held Western science back by about two thousand years and contributed to the existence and persistence of the dark ages. It wasn’t until Newton that the first two claims were established to be incorrect and it took until Dalton in 1803 for the idea of atomic theory to be properly revived. Aristotle’s ideas in physics were basically a disaster.

That said, not all of Aristotle’s thought belongs in the dustbin. I’m personally quite keen on his ethics, for example, although not slavishly devoted to them. He conceived of virtue as being a happy medium between two vices, such as recklessness, cowardice and courage, and the happy medium as not being halfway between the two but closer to one than the other. A frequent source of friction in my life is my belief that tidiness is not only a happy medium between excessive minimalism and hoarding, but that the virtue of tidiness is closer to hoarding and messiness than it is to excessive tidiness, although I may be coming round to a different view as cognitive decline seizes my brain and I stop recognising the positive aspects of messiness.

Another surprisingly accurate area of thought Aristotle actually did excel in was biology. In fact, many of his claims previously put down as erroneous have turned out to be correct more recently. He managed to establish much of the foundations of biology and zoölogy, such as the idea of metabolism, homoeostasis and inheritance, and devised a Scala Natura, which was a hierarchical taxonomy of living beings with humans at the top and other groups further down, organised by their similarity to us, and recognised, for example, that cetaceans are mammals rather than fish. He may also have foreshadowed the theory of evolution, although this is controversial. Many details of animal behaviour turned out to be true, such as the ability of elephants to breathe by raising their trunks above the surface of water when swimming, the existence of dogfish placentæ and the camouflaging behaviour of the octopus. To some extent, Aristotle’s biology is rehabilitated.

Many of his zoölogical claims are set out in his nine-volume work ‘Τῶν περὶ τὰ ζῷα ἱστοριῶν’ – ‘The History of Animals’. There are many false factoids in these volumes, such as the idea that any two species of similar size can interbreed and produce hybrids, hence for example the idea that a giraffe is a cross between a camel and a leopard, but also many truths. From the early modern period up until the late twentieth century, many of Aristotle’s biological attestations, which were sometimes directly observed, often on the island of Lesbos where he stayed for a while, and sometimes taken as reports from fishermen and farmers, were derided and taken to be false for reasons of incredulity.

The bestiaries of the Middle Ages, which were largely allegorical in nature, took up some of his work and repeated and embellished it. Actual clear mistakes includes that female animals, including humans, have fewer teeth than males (this is true for horses incidentally), and apparently that flies have four legs, a claim also made in the Bible, but this may be a misunderstanding or mistranslation of the passages in question. The early modern period, i.e. the sixteenth century onwards, involved a backlash against his claims, and also those made in bestiaries, which led to the rejection of many things which turned out to be true.

One of the more ridiculed claims is made in Book VIII of  ‘Τῶν περὶ τὰ ζῷα ἱστοριῶν’ chapter 28, where it was stated that certain tigers living in Asia Minor and the Caucasus were completely herbivorous, mainly eating fruit. Prima facie, it seems even with modern science that this is completely impossible because tigers, being cats, are obligate carnivores. Cats cannot survive on an herbivorous diet. Their livers are nowhere near as good at detoxifying compounds as found in plants as ours are, and chocolate and xylitol, for example, are famously poisonous to them and dogs. A cat’s digestive system is short like that of other carnivores, giving them insufficient time to break down plant food, and they need fatty acids in their diet in quantity in order for their nervous systems to function effectively. This doesn’t mean a cat can’t be fed a plant-based diet, but it does mean that it would need to be specially designed and manufactured. Hence in the light of modern science, can’t Aristotle’s claim that there are herbivorous tigers be rejected out of hand? The real answer is somewhat interesting.

There was a persistent claim in mediæval bestiaries that certain tigers were indeed herbivorous. This was presented as a foreshadowing of the Biblical claim that one day the lion would eat hay like the oxen, as found in Isaiah 65:25. Although it took a while for biochemistry and other disciplines to establish exactly why, most thinkers in Western Europe ceased to take the idea seriously by the seventeenth century. However, the Arab world had also inherited Aristotle’s tradition, and not only did the belief take longer to disappear there, but in fact it hardly disappeared at all. Western science did influence the Ottoman Empire and led to a situation where belief in herbivorous tigers was considered a quaint folk belief clung to by uneducated tribes in the backwaters of the Caucasus and the like, but it never completely disappeared.

Genetic research and the ability to sequence genomes in detail and compare them between species has led to a revision of traditional Linnæan classification. For instance, there is such an animal as a hedgehog:

And also such an animal as a hedgehog tenrec:

. . . and it might easily be thought that these are just closely related species of mammal found in North Afrika (and Europe) and in Madagascar respectively. In fact, hedgehog tenrecs are as distantly related to true hedgehogs as we are to elephants. A particularly strong example of this is the previous order known as the edentates, supposed to include anteaters, aardvarks, armadillos, pangolins and sloths. Three of those are in fact closely related, but aardvarks and pangolins have nothing to do with the others or each other.

There used to be a subspecies of cat known as the Caspian tiger, who dwelt in the Caucasus, eastern Turkey and Mesopotamia, and was genetically close to the Siberian tigers living on the other side of the mountain. It was these tigers who were rumoured to be herbivorous. Nobody took the idea that they were, and in fact they were often observed eating just like other tigers and were generally the kind of beast it was wise to be wary of, rather like one might be wary of a hornet or wasp to a lesser extent, particularly if one had a severe wasp sting allergy.

There are herbivorous “carnivores”, i.e. animals related to dogs and cats as opposed to animals defined by their meat-based diets. These include the actually omnivorous coatimundi, palm civet and the red and giant pandas along with some species of bear. One rather surprising fact about giant pandas is that they used to live in Bulgaria in the Miocene epoch, and may even have evolved in Europe. There was a species of Balkan giant panda now called Agriarctos nikolovi, who died out due to the climate change caused by the Messanian Salinity Crisis, an incident where the Mediterranean Sea dried out and became a vast salt flat with ground temperatures up to 80°C due to the temporary closure of the Straits of Gibraltar. We are currently living in a temporary respite from this situation but it will have returned by five million years in our future.  Agriarctos nikolovi lived in swampy conditions in Balkan forests and was only able to eat soft plants, unlike today’s giant pandas who mainly, or possibly only, eat bamboo.

It stands to reason, or is at least superficially feasible, that if there used to be giant pandas in the Balkans and there are now giant pandas native to China, there was probably a whole strip of land between Bulgaria and the Far East which was populated by other species of panda. This particular species of panda was around two metres long but not easily able to defend itself, like today’s pandas, although it had retained largely typical carnivore dentition.

It took until the nineteenth century CE for British military campaigns such as the Crimean War and the First Anglo-Afghan War to reveal that there were Caspian tigers. The recently opened London Zoo was ripe to be stocked with captured animals, and several individuals thought to be representative of this species were brought to Britain and incarcerated in those tiny cages some of us remember as still being used in the 1970s. One of them lived out his life in these inhumane conditions, but the other specimen of these magnificent orange and black striped giant moggies, however, suffered a relatively merciful early release when she refused to eat any of the meat supplied to her and starved to death in the midst of apparent plenty. A post mortem carried out on the hapless quadruped revealed a rather startling fact: she was in fact herbivorous. She had a relatively long ileum, and later research in the twentieth century revealed that there were gut flora which produced enzymes enabling the animal to derive nutrition from plant material. It appeared to be a herbivorous tiger!

Closer examination of the animal showed that in fact the apparent “tiger” was no such thing. It was in fact an orange and black striped panda with an unusually long tail. The animal mainly ate leaves, nuts and berries, and due to her recent evolutionary history as a panda and a former carnivore, didn’t succeed in deriving much nutrition from this diet and was rather slothful and lethargic much of the time, but had somehow managed to avoid predation. It’s theorised that these “fool’s tigers” underwent evolutionary pressure to develop a tiger-like appearance which led to animals who might otherwise have preyed upon them to avoid them for fear of being eaten themselves.

This phenomenon is common in the animal kingdom. Known as Batesian mimicry, it involves an innocuous species adopting the appearance or some other prominent feature of a more hazardous species, the obvious example being the various species of hoverflies who mimic the appearance of bees and wasps, but on closer examination turn out to be flies. The animals they mimic have stripy yellow and black abdomens and appear to have a single pair of wings, but in fact wasps and bees have two pairs of wings hooked together to form a single ærofoil. Hoverflies, being true flies, have a single pair of wings in front of vestigial organs evolved from wings called “halteres” which aid balance. It appears very much that fool’s tigers underwent a similar evolutionary journey, changing their appearance from the bear-like black and white unstriped and short-tailed panda to the prominently long-tailed and fearsomely striped tiger. Moreover, although like tigers they are carnivores in a taxonomic sense and retain the dentition of their relatives, with long canines, carnassial teeth and three pairs of small incisors in each jaw, they are in fact entirely herbivorous and can’t eat meat at all. They were named Pseudopanthera dola.

The philosopher Saul Kripke has used the fool’s tiger in his influential work on the theory of names and identity ‘Naming And Necessity’. In his addendum, on page 156 of the 2001 Harvard University Press edition, he points out that an animal with the external appearance of a tiger need not be a tiger because of the existence of this species, and therefore that names are not shorthand for descriptions as had been claimed by the likes of Russell and Wittgenstein.

I have been rather remiss in finishing this post off for publication, and it seems to be around 114 days late.

Why Whales Are Fish After All

I’m not entirely satisfied with the title of this post but I’ve been fishing around for a better one which isn’t forthcoming. This isn’t actually about whales at all, or not primarily so.

I should point out first of all that I do happen to be brewing an appropriately big whale thing, but this here is not that thing. Rather, this has been stirred up by an observation someone made that penguins are not fish. Well, in a way they are.

There are a number of “scientific facts” which are often trotted out which could be argued with given contemporary scientific practice, and they’re along the lines of Pluto not being, or being, a planet. Here are several examples:

• Whales, dolphins and porpoises are not fish but mammals.
• Humans are apes
• Apes are not monkeys
• Birds are dinosaurs.

The last thing is not like the others. Before I go onto that, though, I want to mention something else which is slightly similar. Behind my head, I have a zoology textbook published in I think Victorian times. It’s an appealingly brown cloth-bound tome with illustrations in mezzotint. In days of yore, though perhaps not yore enough, I used it to write two ten thousand word essays in A-level biology about arthropods and chordates, the problem being that actually a lot had changed in the world of zoology in the previous eight decades. Incidentally, the reason I ended up writing such long essays is that one of the other students had insisted that the biology teacher never gave more than seven out of ten because he never had a mark higher than that, and I wanted to prove him wrong. I succeeded. Funny what motivates you, eh? I was also motivated by his homophobia, which I felt made him a nasty person. Anyway, in this two-volume work animals are classified quite differently to how they are today. For instance, arrow worms, now considered to be deuterostomes and therefore quite closely related to vertebrates, were thought to be a form of nematode. Another conflation is between what are now called entoprocts and ectoprocts. These are sessile animals who live in colonies and are superficially like sea anemones or coral. They turn out not to be related to each other at all closely but were once placed in the same phylum. Entoprocts look like wine glasses, and yes they’re transparent like them, with tentacles around the rims. They’re related to arthropods such as insects. Ectoprocts sometimes look quite similar although they vary more and there are more species. They usually live in colonies and are related to brachiopods, the uncannily bivalve-like animals which are in no wise molluscs. The “-proct” bit in their name is the same as the “proct-” bit in “proctologist” – it refers to the anus. Entoprocts have their ani inside the circle of tentacles, ectoprocts outside. They’re really quite similar to each other but are in fact no more closely related to each other than they are to humans. The former phylum, “polyzoa”, included both but it was later realised that they had nothing to do with each other. The ectoprocta, also known as the bryozoa, is the largest minor phylum. Animals have about seven major body plans organised into phyla, and about four or five dozen minor body plans. Some of these are only found in a couple of species, and there’s a big gap between the diversity of the minor and major phyla, but ectoprocts are the largest phylum that isn’t enormous. It’s like Leeds – the largest British city which isn’t enormous.

All that said, entoprocts and ectoprocts have similar lifestyles and it’s fair to group them together. But small flower-like animals living underwater could be hard to relate to. Humans like things with backbones, or at least most of what we seem to be able to relate to has a face and a bony internal skeleton. Some people tend not to dignify most of the animal kingdom with that monicker. Ironically, most organisms called “animal” are actually just mammals apart from one species, and this is where cladistics become manifest, because in fact although everything conventionally called an animal is one, but so are lots of other species. When the book in question was published, there was an order of mammals called the edentates – mammals without teeth. In fact this is in any case a misnomer since in fact one family under this heading, the armadillos, have more teeth than any other mammal. Sloths and anteaters were also considered edentates. In the past, pangolins and aardvarks were too, even though they lived in the Old World and other edentates lived in the New. All that said, it’s undeniable that they’re similar.

Armadillo

Pangolin

Giant anteater

Aardvark

I’ve already said that I wonder if people know more about aardvarks than other animals because they come early in the dictionary or encyclopaedia and therefore fatigue has yet to set in. But anyway, look at this set of four animals. Do they not seem to be closely related? The first two are armoured and able to roll up to protect themselves. The other two have degenerate teeth and dig into insect colonies to eat them with powerful claws. Nonetheless only the first and third are closely related, In fact these animals along with sloths form a sister group to all other placental mammals. Pangolins are most closely related to carnivores and aardvarks to the likes of elephants. Cladistics completely sunders this group.

All that said, there is a “type” which includes only distantly related mammals such as numbats, echidnas, tamanduas and aardvarks as related in terms of being similar in form, and another “type” comprising pangolins and armadillos, though more loosely. I’ll come back to this because cladistics are what leads to peculiar, “common sense”-type results in some situations, one of which has already been noted.

A clade is defined as a group of genetically related organisms. Clades can occur within species. For instance, my mother line forms a clade which is most common among Libyan Tuaregs and my father’s line among people in the Gaeltacht. Like other individual organisms of sexually reproducing kinds, I am in several clades. Like all living humans, I’m also in other clades. I’m in Y-chromosomal Adam’s clade and in mitochondrial Eve’s, whereof the aforementioned Gaels and Tuaregs also are respectively. However, clades are more often used to group entire species. A clade is a group comprising all evolutionary descendants of a common ancestor, usually understood to refer to an entire community rather than an individual or pair, although it could.

This is why, first of all, birds are dinosaurs. Dinosaurs are defined cladistically as something like “the most recent common ancestor of the house sparrow and Triceratops and all of its descendants.” I find this definition slightly confusing because it used to be taught that there were two taxa of dinosaurs, the saurischia and ornithischia which were not particularly close to each other. The taxon “Dinosauria” had been retired. The sauropods are also included by mentioning Diplodocus in that definition. The fact that ornithischia means “bird-hipped” and saurischia “lizard-hipped” is also odd because it means birds are lizard-hipped rather than bird-hipped even though their hips are obviously those of birds. In terms of the actual form of their bodies, as opposed to their DNA, dinosaurs are archosaurs whose hind limbs are vertical and stay under their bodies when they walk. This is not true of other archosaurs such as crocodiles. The really big change in the perception of dinosaurs was probably when it was realised that many of them had feathers, although not all of them, and the presence of hair-like skin appendages might even be a primitive feature as pterodactyls, strictly “pterosaurs”, who are not dinosaurs but are related, , have a hairy covering. This means that not only were many non-avian dinosaurs feathered but that they often looked a lot more like birds than their classic depictions do.

Then there’s the rather startling whale situation. If I remember right, at some point, possibly in the 1980s, whales were thought to have evolved separately from two different lines of terrestrial mammals, one for the baleen whales such as the Blue and the other for the toothed ones such as the Sperm. This is no longer accepted, and in fact I might have remembered it wrongly. Whales are now considered artiodactyls. That is, they’re in the same order as giraffes and gazelles. Even-toed ungulates, i.e. animals with an even number of hoofs on each foot. This is an old-fashioned definition as obviously whales don’t have hoofs at all (“hooves”?). In fact one way of spotting the resemblance is to look at the ankle bones of primitive whales and terrestrial even-toed ungulates, which have a distinctive double-pulley form into which the tendons fit, found in no other mammals. Another way of looking at it is to consider the hippo:

It’s been recognised for ages that hippos are ungulates, but it was also thought that they were most closely related to pigs. In fact it turns out that pigs are not that close to them but are fairly clearly related to peccaries. Hippos are descended from much less bulky animals, basically lightweight hippos which were already amphibious but not heavily built, and although they spend a lot of time in the water they entered it separately from their relatives the whales, and the adaptations they have evolved independently. Another big difference between the ancestors of whales and hippos is that the former were predators. Whales were originally like mammalian crocodiles, waiting for prey in shallow water, possibly to ambush them, and with long jaws filled with teeth, but of course mammalian. Although they aren’t that basal, river dolphins, who have evolved separately more than once, give a good impression of what whales previously looked like:

It does seem very far from obvious that giraffes and dolphins are in the same order though, and this is one consequence of cladistics. There is, however, another consequence which falls into the category of accidental correctness. It used to be trotted out regularly that whales and dolphins are not fish but mammals, because they have no scales, are “warm-blooded”, give birth to live young whom they suckle, and breathe air There is a bit of an issue with several of these points, because there are fish with no scales such as catfish, “warm-blooded” fish such as opahs and tuna, fish who give birth to live young such as swordtails and guppies, and fish with lungs who breathe air, and in fact in the last case the condition of having lungs is found in very early, fully aquatic fish such as the Devonian arthrodires. Also, although as far as I know there are no fish who secrete milk, sharks do provide food for their offspring from their bodies when they eat the eggs of other embryonic sharks within their mothers. Technically there’s no reason why there couldn’t be a “warm-blooded”, air breathing, scaleless fish who gives birth to live young, and when I say “fish”, I do mean the things that are closely related to salmon and cod, and not some exotic definition.

However, cladistically whales are fish because mammals are fish. The first fish to develop limbs with digits who was ancestral to all land vertebrates and also all vertebrates descended from land vertebrates such as ichthyosaurs, penguins and seals, was a fish. We are descended from fish and to fish some of us have returned, in terms of gross physical appearance, and cladistically, everything descended from a fish is also a fish, just as everything descended from a dinosaur is also a dinosaur, even if she’s a humming bird. Therefore, whales are fish. This is a bit annoying for pedants because they can’t now go “um, actually. . . ” in a stereotypically nasal voice about it any more. Nevertheless it is so. They’ve taken away our toy. But whales are fish in the same sense that kangaroos are.

There’s another, similar consequence to this though, or rather a couple of related ones. It’s best to start at the end here. Humans are apes. This is actually true in a couple of ways. Humans are descended from apes, so in a cladistic sense we are apes. In more detail, we really, really are apes. Considering the great apes, which consist of two species of orang utan, two species of gorilla, humans, bonobos and chimpanzees, the three species mentioned last are closely related to each other and more distantly related to the gorillas, but the real outliers are actually the two species of orang utan, not the humans. This shouldn’t be that surprising considering that orang utan are east Asian whereas the rest of the surviving great apes, including humans, are Afrikan in origin. In that sense, then, we are apes. We’re actually basically the “third chimpanzee”, as Jared Diamond puts it. I find this a little difficult because I think we more closely resemble gorillas physically than we do chimps or bonobos, but this is probably just because we’re larger than the other two and therefore have a more similar build to gorillas for biophysical reasons. Another aspect of human biology which is a little surprising is that certain features of our bodies are more primitive than those of other apes, so in fact we aren’t just great apes but also in some ways quite primitive great apes compared to the other species. Specifically, gorillas, chimps and bonobos have hands adapted for knuckle-walking, whereas human hands are more like those of Miocene apes who hadn’t gone through that process yet.

We are also cladistically apes, in the sense that we are members of the clade including the species mentioned above and our common ancestor would very obviously have looked like an ape to us. This also means there’s no missing link between apes and humans, because the apes who evolved into humans are also the apes who evolved into other apes. The exact lineage of humans is hard to identify because there was a huge “thicket” of ape species in the Miocene, when apes were much more common and diverse than non-human ape species are today. It also usually turns out that when a fossil organism is found, it can’t be definitively said to be a direct ancestor of anything alive now. Humans actually tend to be an exception to this. For instance, Homo heidelbergensis seems to be straightforwardly the ancestral species to all living humans. It can also be difficult to find fossil apes because they’re less likely to die accidental deaths. A rhino might wander into a tar pit and suffocate, or a sabretooth tiger might see a pile of dead animals killed by poison gas from a lake and be poisoned herself, but an ape is more likely to notice the corpses, become suspicious and avoid the hazards. All that said, here’s an example of an ape who is close to our common ancestor:

This is Proconsul africanus, who lived from twenty-three to fourteen million years ago around Lake Victoria and on islands in that lake, eight million years before “Lucy” and dying out around the time orang utan diverged from the other apes, all of which had a common ancestor at this point. Gorillas diverged from other Afrikan apes a couple of million years later and then chimps and bonobos from humans six million years ago. Bonobos and chimpanzees then split less than a million years ago, by which time our own genus existed. Proconsul was more quadrupedal than today’s apes, and as can be seen from the image, the hands are more like ours than other apes’, this being a “primitive” feature.

There are things to be said about primates and their relatives, but before I can get to them it would probably help to look at another example of a mammalian order which, unlike primates, we don’t belong to. There’s no particular reason to select them except that a lot of their species are familiar to us, but the carnivores are worth looking at, as would rodents and a load of others, but why not? First of all, carnivores have a significant point in common with the artiodactyls in that they’re divided into terrestrial and aquatic forms, seals being carnivores too. They’ve been called fissipeds and pinnipeds, that is, carnivores with split feet, i.e. digits, and carnivores with feather-like feet, in other words flippers. Concentrating on the land-lubbers gets us two main divisions, into the feliforms and the caniforms, i.e. cat- and dog-like animals. Some animals are in unexpected places. For instance, hyaenas are considered cat-like and there used to be animals which were like a cross between dogs and bears, which diverged early from the other caniforms. There is a more obvious basal versus derived distinction among the feliforms than the caniforms. That is, the feliforms do still have more notably “primitive” types than the caniforms. These are the vivierrids, including the genet, whom Sarada and I once witnessed rummaging around in bins in France when we were sleeping rough. On the caniform side, there’s a group called the mustelids, which includes badgers but also animals like ferrets, minks and stoats, and it’s easy to see how they blend into otters and seals. As far as cats and dogs themselves are concerned, whereas there are people who prefer one or the other, it wouldn’t be sensible to see either as “more advanced” than the other. They’re simply different kinds of carnivore. There is a trend of specialisation within each group, which among the caniforms seems to peak in something like bears or walruses, but it still doesn’t seem like there could be a ladder of different species of carnivores with something at the top. We’re invested emotionally in carnivores because we bond with dogs or cats, or we see bears as charismatic or pandas as cute, but we can still be objective about them.

The way we think of primates tends not to be like that. The standard popular narrative seems to be dominated by a hierarchy, beginning with tupaias, which are not actually officially primates but are related along with rodents, lagomorphs (including rabbits and hares) and colugos. I’m going to permit myself a slight digression here: lagomorphs and rodents are distinguished and considered to be in different orders, but are also closely related, and if the division was placed a little higher than it currently is, they would be in the same taxon. So, there’s a superorder of mammals I tend to call the Euarchontoglires but is also known as the Superprimates, consisting of lagomorphs, rodents, colugos, primates and “tree shrews”. The rodents and lagomorphs are called Glires and belong together, and since it used to be thought that primates were closely related to bats, the “ladder” idea hasn’t been imposed on them and they aren’t seen as of a rank in that hierarchy. To get back to the point, the way it generally goes is that we see tupaias – tree shrews – as at the bottom, prosimians as a bit further up, tarsiers as further up still, then New World monkeys, Old World monkeys, lesser apes and great apes, in that order. That isn’t how things are. There is a sense in which tupaias are similar to ancestral primates who were around at about the time the non-avian dinosaurs were wiped out, but beyond that the prosimians, though older than the simians, have been around ever since simians evolved as well. It’s just that one set of prosimians turned into tarsier-like forms and then into monkeys.

So: humans are apes, but despite the insistence to the contrary, apes really are monkeys. We are a special kind of monkey, but so are marmosets. Old World Monkeys form a clade, defined as catarrhines, and include apes. Although we think of monkeys as living in trees and having long tails, on the whole, exceptions being many such as macaques and baboons, and of course apes, we are Old World monkeys. For instance, New World monkeys tend to be smaller, have prehensile tails and are platyrrhine – their nostrils are on the sides of their noses. Humans are not like that. We’re bigger, tailless on the whole, and are catarrhine. Hence the similar insistence that apes and monkeys shouldn’t be confused is as unscientific in its own way as the idea that whales are not fish. Whales are fish, and apes are monkeys.

There is, though, a problem with this insistence, or rather there are two problems. The more obvious one is the overtly and actively racist use of apes and monkeys as terms to refer to Black humans. As a White person, it would be distinctly dodgy for me to go up to a Black person and call them a monkey or an ape, and equally the AI face recognition algorithms which identify Black human faces as gorillas are the product of racism. Therefore, there’s a separate problem with even using the words “monkey” and “ape”. The words “catarrhine”, and “simian” for the whole lot including New World monkeys, and the word “hominoid” for apes might be better. In fact, there’s even another problem with the English term “New World monkey”, because the New World is arguably only new for Europeans, although it’s also true that humans got there later, after evolving in the Old World.

Besides all this, though, there is a potential issue with the idea of cladistics being somehow more fundamental than the older form of biological taxonomy, which was invented before evolutionary theory. Obviously I’m not creationist, but I do feel that evolutionary theory has been allowed to dominate in a similar way to how orbital dynamics was allowed to dominate astronomy, leading to Pluto’s demotion. Yes, Pluto’s orbit is not like that of Jupiter’s or Venus’s, but it’s a big spherical lump of rock and ice thousands of kilometres in diameter. Likewise, a whale is a fish, but an odd fish because of having mammary glands, a four-chambered heart, blubber, no scales or lateral line, and so on. But there is another sense in which aquatic vertebrates with streamlined bodies, dorsal fins, feather-like limbs and tails with “foils” on them really are similar to each other, and this needs to be acknowledged because it has ecological and physical significance. Taking this to humans, genetically humans are closer to chimpanzees than gorillas, but because we are also closer in size to gorillas than chimps, we kind of form a group with gorillas which excludes the more closely related chimpanzees and bonobos. Likewise, pigs and hippos aren’t as closely related as hippos and whales, but pigs and hippos are similar in other ways.

In philosophy, there’s a concept of the “natural kind”. This is the idea that there are categories out there in the world which exist whether or not we realise it. It’s tempting to look at clades not only as natural kinds, but also as somehow more important than other biological natural kinds, based on genomes. This priority runs the risk of ignoring equally valid natural kinds in the form of ecological niches and physical similarity. It is actually important for whales and sharks to be streamlined in similar ways, and for echidnas, tamanduas, numbats and aardvarks all to be mammals who eat social insects as the main part of their diet. This sort of natural kind doesn’t seem any less valid to me than clades, and to be honest I think we should have a second taxonomical system which groups these together as well. Otherwise, imagine this. Humans discover a very Earth-like planet on which there are organisms who move around of their own accord on land and in the water, have hard internal skeletons and a segmented hard structure along their backs carrying nerves to the organs of the body. Some of them dig in the ground and have long noses which they used to eat small motile organisms who live in colonies. Some of them are fish-shaped and descended from land-living organisms of this kind. Some of them are bipedal, have large brains and are about 170 centimetres in height as adults. All of these organisms give birth to live young and suckle them with milk which they secrete themselves. However, life appeared on this planet from non-living processes as it may have done here, or alternatively was seeded, as may have happened here, from elsewhere. Hence there is no genetic link between these fish-like “warm-blooded” organisms and whales, between the long-nosed small colonial organism eaters and anteaters, or between the bipedal one with hands and big brains who make spaceships. None of these organisms are animals according to cladistics. Nor are they mammals, even though they tend to be furry, suckle their young and give birth to offspring without laying eggs. Is this a sensible way of carrying on?

There is more than one kind of natural kind which is equally valid and scientific and can be applied to the same field of knowledge, if natural kinds exist. And whales are fish after all, in two different senses.