The Skeleton
That Skipped Bone

"Cartilaginous" makes it sound floppy. It isn't.

A shark's skeleton is cartilage with a mineral crust laid over it — thousands of small blocks, packed edge to edge like paving, sitting on top of an uncalcified core. The blocks are called tesserae, from the word for mosaic tiles, and that is exactly what they look like.

Mason Dean and Adam Summers, reviewing the tissue in 2006, describe a skeleton whose mineralisation comes in distinct types — areolar, globular, prismatic — arranged differently depending on the animal's age, its species, where in the body you're looking, and how it feeds. The skeleton is tuned to the life.

And the design does something bone can't. A tiled surface over a soft core bends further before it breaks, then springs back. It's lighter than bone. It doesn't need marrow cavities or a blood supply threaded all the way through.

None of that is a workaround. It's a different set of trade-offs, chosen — over deep time — by an enormous number of successful animals.

For most of a century the shark was taught as the before picture.

Cartilage first, bone later — sharks as a living snapshot of the stage vertebrates passed through on the way to becoming us. Primitive. Ancestral. Not there yet.

The fossils stopped cooperating. In 2020 Martin Brazeau and colleagues described Minjinia turgenensis, an Early Devonian fish from Mongolia on the placoderm grade — close to the common ancestry of all jawed vertebrates — and it is full of endochondral bone. The kind sharks don't have.

Which flips the sequence. If the shared ancestor already had bone, then the shark's bonelessness isn't something it never got round to. It is something its lineage gave up. A derived condition. A loss.

We have run into this exact shape before, one zine ago. The crab body plan was gained five times and lost seven — leaving turned out to be the commoner event. Here it is again in the skeleton: subtraction is not the same as never having arrived.

And whatever they traded away, they have been fine. The chondrichthyan record runs back to the early Silurian — call it 440 million years, on scales and teeth at first. Four mass extinctions. Still here.

Here is what happened next to the skeleton we've just spent five pages admiring.

Somewhere along the way a claim got loose: sharks don't get cancer. Cartilage has no blood vessels of its own; tumours need a blood supply to grow; therefore — the reasoning went — a shark must be carrying something that stops them. Grind it up. Take it as a powder.

It became an industry. Capsules, powders, whole shelves of them, sold to people who had just been given the worst news of their lives and were looking anywhere at all.

Notice the shape of the claim, because it is the important part. The animal is no longer an animal. Once you've decided a body contains the answer to your problem, the body stops being a life with its own reasons and becomes a supply.

And then there's the small matter of whether it was true.

They always did. Somebody just had to go and count.

In 2004 Gary Ostrander and colleagues went through the literature and the Registry of Tumors in Lower Animals and found 42 documented tumours in cartilaginous fishes — across at least 21 species, in nine families and seven orders. Twenty-four in sharks, sixteen in skates and rays, two in chimaeras.

Tumours of the nervous system, the gut, the skin, the blood-forming tissue, the reproductive organs, the endocrine system — and of the skeleton itself. At least fifteen were malignant, invading normal tissue. Their paper's title says the quiet part: Shark Cartilage, Cancer and the Growing Threat of Pseudoscience.

Then it was tested properly. Charles Loprinzi and colleagues ran a randomised trial in patients with advanced cancer and reported in 2005: no difference in survival, no difference in quality of life, and side effects bad enough that people struggled to keep taking it.

So: the premise was false, the product did nothing, and the animals were killed anyway.

This is the sentence the zine exists for, so here it is plainly.

The shark was not harmed because anyone hated it. It was harmed because somebody decided its body contained something useful, and once that decision is made, everything else follows without anyone needing to be cruel on purpose.

You stop asking what the animal is doing with its own skeleton. You start asking what the skeleton can do for you. And then you go and get it.

It is the same operation when it's aimed at people. We know this frame very well:

the search for the cause, so there can be a cure. The interest in Autistic people that arrives only as what are they good at, could we use that. The inspiration story where a disabled life is raw material for somebody else's lesson. The research funding that goes to prevention rather than to the things we've actually asked for.

All of it starts the same way — not with hatred, with usefulness. A body is read for what can be extracted, and the reading feels like appreciation right up until the moment it costs you something.

Everything in this zine turns on one question, and it's a question that gets asked about people constantly.

What is it for?

Asked of a shark's skeleton, it produced a shelf of pills that didn't work and a lot of dead animals. Asked of a person, it produces the same shape: what are you good for, what does your difference get us, where's the upside.

You've probably been handed the flattering version. Autistic people are so detail-oriented — brilliant for quality assurance. It sounds like praise. It's a receipt. It says the welcome is conditional on the yield, and quietly hands you the bill if the yield stops.

So here is the plain form of the refusal, which is the same one we'd make on the shark's behalf if it could be bothered to care what we think:

The skeleton is for the animal. Your mind is for you. Not a resource. Not a lesson. Not a supply. A body doing the work of being itself, which is the only justification anything in this universe has ever had, and it has always been enough.

Four hundred million years of no bone at all, and nobody down there is apologising.