GoatMan

  As the dissection progresses Venus changes from the familiar form of a goat (though dead) to something unfamiliar, an interconnected system of internal organs in a cradle of muscle and bone, then back to something familiar: separate organs and bits of limb that we recognise from butchers’ shops or supermarket chiller cabinets.

  Now, I’m actually quite a squeamish person, so I’d been expecting to find cutting into poor old Venus quite difficult to handle. Later I will barely be able to watch some of the video that my friend Simon shoots (especially the bit where we’re cutting away the skin around Venus’s mouth to reveal the muscles that give her those prehensile lips), but in the actual moment it’s fine—though completely weird and out of my everyday experience. For the biologists in the room, of course, it’s completely routine: at the same time we are dissecting Venus, another group is dissecting an alpaca; at one stage, it seems it might’ve died of tuberculosis (luckily that turns out not to be the case or everyone present would’ve had to be quarantined). Another group is performing an autopsy on a huge, white, fluffy, dead Pyrenean mountain dog.

  I do struggle a bit when the technician hacksaws open Venus’s skull (the sound of saw on bone is somewhat emotive). And though by the end of the second day, I’ve really had enough of the smell of goat mingled with intestinal contents, the iron scent of blood, and the antiseptic of the dissection room, the gore of it all has been subsumed by this fascinating opportunity to explore goat anatomy from the outside in. It has hammered home just how mechanically subtle a body is: each bone in Venus’s body seems shaped to optimise for multiple criteria, and connected with muscle and sinew to make a range of movements as energetically economical as possible.

  In terms of engineering, designing a system that lets me adapt my existing anatomy to approach the sophistication of Venus’s is finally starting to seem, um, bloody impossible.

  Professor Hutchinson asks if I’ve seen the running quadruped robots built by Boston Dynamics with funding from the Defense Advanced Research Projects Agency. Yep, they’re pretty scary.

  To make a hand into a hoof, elongate the bones of the hand and fuse the fingers.

  “Well, with trying to design a robot that runs around on four legs, we’re just getting there, but it took over a hundred years of robotics research. And that’s designed from scratch. Working from your existing body, with all its existing parameters, is going to be much more difficult to do.”

  When Professor Hutchinson has to rush off to discover new dinosaurs/ attend a faculty meeting, he leaves me to assist one of his PhD candidates, Sophie Regnault, and the resident vet, Dr. Alexander Stoll. Sophie is collecting kneecaps. She’s keen to take Venus’s for her doctoral thesis because she has kneecaps from all manner of exotic species but none from the lowly old Capra hircus.

  We cut off Venus’s legs (and Sophie cuts out her kneecaps), and I see that, as Geoff had pointed out, Venus’s thorax was basically just suspended between her two front legs in a sort of muscular sling without any bony joints, a very useful adaptation if you do a lot of jumping down off ledges headfirst. As Dr. Stoll says, “an impact like that would tear out our collarbones. Goats have no collarbones because they would just get in the way. Goats need to run, not carry shopping bags.”

  Nonetheless, as we work away, I can see that in gross biological terms, Venus and I—and indeed all us mammals and most of the other animals on Earth, too—match the basic description of a fleshy tube with openings at both ends. And hanging off our tubes are various weird and wonderful appendages for such things as moving our tube around so it can get more food into the intake end in order to live long enough to make more fleshy tubes. Not the most sublime description of the animal kingdom, but true nonetheless of goldfish, finches, octopuses, spiders, penis worms, diplodocuses, me, your mother, my mother, elephants, goats, and most of the rest of us categorised as symmetrical animals. We are the Bilateria, the group in the tree of life to which 99 percent of animals belong, the vast majority of which share the distinction of having a mouth and an anus. Not flatworms, though; they have only one dual-use opening.

  Comparative anatomy.

  The organ that made Venus Venus. About a tenth the weight of the one that makes us us.

  So we have the same basic plan, all those homologous structures and such, but, as I’d been learning, the devil is very much in the details. While goats and humans are the same in many ways, since our lines diverged five million years ago, we’ve been evolving into bipedal, digitigrade, shopping-carrying omnivores, while they’ve specialised into quadrupedal, cloven-hoofed, unguligrade, cursorial ruminants. We have more brains, but what goats lack in brains, they make up for in…

  Guts

  Goats have a lot of them.

  There are many ways to skin a cat and many ways to dissect a goat. The way Dr. Stoll has chosen elegantly illustrates my feeling that we’re all just tubes with appendages. With just a couple of incisions and a ta-da flourish, he’s separated Venus’s organs all the way from tongue to anus. He slides out the guts (and there are a lot of them), and we lift the whole interconnected mass over to another table.

  Sophie kindly offers me some Vicks VapoRub to dab on my chin to try and mask the smell as we start to examine the gastrointestinal tract. I’m particularly interested in this part of Venus’s anatomy because, as we know, one of the things that goats excel at, along with galloping and clambering around mountains, is eating. And while Dr. McElligott corrected my notion that they’ll eat anything, they are able to eat a wide variety of plants, such as those that grow on the green Alpine slopes. This is an ability I very much wish to acquire myself.

  Dr. Stoll traces the path these foodstuffs took through Venus as they were converted into Venus. So we start at the tongue and trace down the esophagus, past Venus’s larynx, and into the bits that were contained within her abdominal cavity.

  Goats are foregut digesters and confusingly also have four guts. They need all these extra guts because, like all mammals, they lack the ability to produce the enzymes that let them digest cellulose and lignin. This seems rather an oversight, as most of the plant matter they eat is made of cellulose and lignin.

  Goat gut microbe farm.

  Many microorganisms, on the other hand, can synthesise these enzymes. So goats and other foregut digesters have evolved a symbiotic relationship with these microbes: they provide microbes living space in their guts, and the microbes deal with all that tough cellulose and lignin through microbial fermentation. This is a slow process, however, requiring time and space in order to occur, hence the four guts we’re looking at on the dissection table.

  The first two of these are the rumen and reticulum. The reticulum is a kind of small, dead-end pouch at the top of the rumen, in which ruminants store the bit of foliage they’re currently ruminating on before they regurgitate it back up the throat to continue chewing it. The fact that it’s already been down once means the microbes have had a go at it for a while and softened it up, so it can be chewed up further before heading back down to the rumen so the microbes can really get at it again.

  Venus’s rumen and all-important rumen fluid.

  Attempting to untangle the intestines.

  “So is the reticulum the equivalent of our appendix?” I ask.

  “No,” Dr. Stoll replies.

  Sophie cuts the rumen open, and a kind of brown soup flows out, along with little flecks of Venus’s last meal (looks like she went for grass). This is the rumen fluid, which is full of the microbes—the bacteria, fungi, and protozoa—that together let ruminants do what we can’t: digest the cellulose in plant matter.

  “The rumen and reticulum act as a big internal fermentation chamber; the bacteria that live in there do all the work,” Dr. Stoll explains. “It’s the bacteria in the rumen that make enzymes that actually break the grass down into what are called volatile fatty acids, because the cellulose in the grass is actually indigestible by mammals.”

  “So what’s after the rumen?”

&nb
sp; “Next is the omasum, which has leaves like a book and is like a physical sieve, only letting small particles through to the abomasum. It’s the abomasum that is the equivalent of our stomach. Everything before is like the top of our stomachs, but gone mad. The abomasum has all the familiar acid in it and does the digestion proper.”

  All of these workings are wrapped in a big piece of fatty tissue called the omentum, which, according to Dr. Stoll, makes a delicious type of Greek sausage.

  For us, lacking a rumen and its inhabitants, cellulose is dietary fibre. And, though important for one’s bowel movements, it passes through our guts without providing much in the way of energy, whereas for ruminants it’s their main source of nutrition. It’s like goats have a sort of internal farm, where they cultivate the microbes in their rumen by supplying them with plenty of grass so they can grow and multiply and produce these nutritious volatile fatty acids. These are filtered into the abomasum, along with a good proportion of the microbes themselves, where the goat finally digests its harvest with stomach acid in familiar fashion. Goat eats grass, microbes digest grass, goat digests microbes.

  The biopsies from Venus’s intestinal tract.

  The tour of Venus’s gastrointestinal tract continues to her intestines. Sophie offers me a top-up of Vicks before she begins cutting them open with scissors. The contents of Venus’s intestines aren’t fluid like that of the rumen. By now they are much more solid, much more recognisable.

  Dr. Stoll cuts two little chunks from Venus’s intestinal wall to examine later under the microscope for the deadly Johne’s disease–causing MAP bacteria. And that’s that.

  When Venus was brought into the dissection room, she was categorised as a potential biohazard, so her remains can leave only as smoke and ash from the furnace. But as we’re clearing up, the lab technician offers to process the bones using their special bone-cleaning system, which would mean I could collect them and take them away a couple of weeks later. I consider momentarily: Will Buttercups be OK with me reassembling Venus’s bones? A skeleton is surely a less emotive thing than a recognisable individual? Oh, dear, I hope I’m not about to confirm their worst fears about the arts.

  I reply: “Yes, that’d be great, if not too much trouble.”

  “No, no trouble. You might have trouble putting the skeleton back together, though…”

  The thing is, I’m not going to be very free of human concerns if every few hours I have to worry about where the next Swiss fondue restaurant is (and the consequent concern of how to pay for said fondue). So I need to find a way to be able to eat grass. And not just eat grass, but digest it. Anyone can eat grass. Tragically, during the Irish Potato Famine of the 1840s, people who had died of starvation were often found with their mouths stained green from all the grass they’d been eating to no avail, because we humans lack that crucial set of gut microbes that can digest cellulose.

  Working out which bones connect to which bones is tricky…

  We do, of course, have our own set of gut microbes, our microbiome, that live in our intestines and help with our digestion. My first idea for giving myself the ability to digest cellulose was to add microbes from a goat’s gastrointestinal tract to my own, using a technique called faecal microbiota transplantation. This is a procedure usually used to replace a patient’s malfunctioning gut microbiome with that of a healthy person. So I thought if I transplanted the microbes from a goat’s guts into my own guts, I’d get the goat’s ability to digest cellulose.

  I decide to make a virtue of my ignorance and imagine: If Venus were one of us, what would she be like?

  If only it were as simple as a goat-poo enema.

  From dissecting Venus I now understand that in a goat, cellulose is broken down into digestible products before it gets to the stomach and intestines, the place where humans’ gut flora reside. What I need, of course, is to make myself an artificial rumen. At this point I’ve been round the block a few times, so I know an artificial rumen isn’t likely to be possible. But my research leads me to the Herbivore Gut Ecosystems lab at Aberystwyth University, where they use just such a device!

  I give them a call and speak to the lab’s leader, Dr. Alison Kingston-Smith. Her group is trying to understand what goes on in a ruminant’s rumen, and her specific project is an investigation of how the plant cells themselves react to suddenly finding themselves being eaten and digested. This may seem rather niche, but the fermentation process that plant matter undergoes in ruminants like goats and cows produces methane, a potent greenhouse gas. The burps of farmed ruminant livestock together are the largest global source of methane, and emissions from livestock in general account for around 18 percent of greenhouse gas emissions, slightly more than all of the world’s road vehicles, ships, planes, and trains. Understanding what’s going on as plants are digested in the rumen could allow the grass to be changed or the balance of rumen microbes adjusted so as to reduce, or completely eliminate, the methane produced. That’s to say nothing of simply making the rumen more efficient at turning grass and so on into animal. Considering that the global demand for meat is projected to triple by 2050, even small changes to rumen emissions and efficiency have huge environmental implications. I think I’ll become a weekday vegetarian.

  After explaining the broad theoretical basis of my project, in turn, I get specific with Dr. Kingston-Smith.

  “What I was thinking was I could get a sample of a goat’s rumen fluid…”

  “Yes.”

  “And put it in a fermenter, like a big kind of bag…”

  “Yes.”

  “And add some grass and foliage…”

  “Yes.”

  “And then culture the rumen fluid microbes…”

  “Yes. That’s pretty much what we do.” Dr. Kingston-Smith says. She’s sounding quite jolly.

  “Great! On the right track then! So then the microbes would grow, fermenting the grass…”

  “Yep.”

  “And I could then strap this bag to my torso and spit chewed up grass into one opening and suck the cultured microbes and volatile fatty acids out another opening like a milkshake, so I can digest them in my true stomach and live off grass in the Alps like a goat.”

  Dr. Kingston-Smith adopts a sudden change of tone.

  “No. No, I wouldn’t do that if I were you.”

  It had all been going so well. She continues, sounding somewhat grave.

  “There are…issues of safety associated with that proposal. With new sequencing technologies, we’re discovering all sorts of things that are part of the rumen mixture that we wouldn’t expect to be there. And some of them aren’t altogether benign. The ruminant has evolved this complex mixture of bacteria, fungi, protozoa, archaea, lots of different categories of microbes. We don’t know the totality of what’s in there.”

  “Right. I see.”

  “There are hundreds—hundreds and hundreds—of different species in there. In the last ten to fifteen years, people have been using molecular tools to actually go in and find out how diverse the population structure is, and we’re seeing that things are more complicated than we’d ever predicted.”

  “Right.” Typical.

  “And so there are still an awful lot of unknowns in there.”

  “Yeah…”

  “Yes, so I had a feeling that’s where you were going, but from a safety point of view I would strongly suggest you didn’t do that.”

  Now, in general I consider myself to have a fairly robust composition, and I’m not one to shy away from the odd calculated risk, so imbibing a bit of fluid cultured from a goat’s rumen wouldn’t usually be the sort of thing that would concern me. I mean, the acid in our stomach is there to attack and break down cells, whether they be animal, vegetable, or bacterial. So I’d assume that the acid in my stomach would just digest whatever bacteria and so on I happened to be cultivating in my proposed artificial rumen. Indeed, the whole point of a rumen is to provide a perfect environment in which to grow bacteria as they feed on grass, so
one’s stomach can then digest the bacteria and their products in turn.

  But the thing is, in researching my first nonplan of giving myself a DIY goat-poo enema, I’d, of course, read plenty of stories from people suffering from debilitating and extremely unpleasant gut conditions through being colonised by some unfriendly bacteria or other, which they were trying to cure through faecal microbiota transplants. And sure, while humans delight in eating all sorts of weird and wonderful products of microbial fermentation—yogurt, sauerkraut, kimchi, ten-thousand-year-old eggs, not to mention alcohol—and our stomach acid will usually just take care of the microbes responsible, it can also be overwhelmed (as I’d recently discovered by reheating a rice-and-shellfish dish after it’d been in the fridge for few days). So I could see Dr. Kingston-Smith’s point: culturing a vat of thousands of unknown species of microbe and then eating whatever resulted on purpose could be playing a bit fast and loose with one’s long-term health. The risk would be not just giving myself a bad case of food poisoning, but acquiring a permanent, debilitating gut condition as well. Turning up to my doctor’s with persistent bouts of diarrhoea and describing my history would be pretty embarrassing.