The Hair and the Oath: What Happens When You Follow the Evidence in Cryptozoology All the Way Down

There are two documents worth holding side by side this week. One is a sworn legal deposition from 1811, preserved in the Scottish Archives, in which a twenty-three-year-old tenant's son named John McIsaac described crawling on all fours through a field of corn to get close enough to identify something he had never seen before. The other is a 2014 paper in the Proceedings of the Royal Society B, in which Bryan Sykes and colleagues ran mitochondrial DNA sequencing on thirty hair samples attributed to anomalous primates — Bigfoot, yeti, almasty — and found that every single one of them matched a known species. Bears, raccoons, horses, cows. Two Himalayan samples matched a Palaeolithic polar bear, which was genuinely interesting. None matched anything unknown.

These two documents are not in conversation with each other in any obvious way. McIsaac was describing something that happened on a specific rock on the east coast of Kintyre on a Sunday afternoon in October. Sykes was running gel electrophoresis on fur samples mailed in from around the world. But together they define the two poles of what cryptozoology actually is when you take it seriously: the irreducible witness account, and the physical evidence that keeps not quite arriving.

McIsaac's deposition is worth reading in full if you haven't. The detail that stops me every time is the hair. He describes the creature lying on the rock on its belly, head toward the sea, upper half white and shaped like a human body, lower half brindled reddish-grey and apparently scaled, tail greenish-red and shining. And then: the wind blew off the land. And when it did, the creature raised one hand and stroked its hair back. Then leaned the other way and stroked the hair on the other side. Twice. He watched it do this twice.

He was under oath when he said this. The Sheriff Substitute of Kintyre, Duncan Campbell, signed the deposition. This was not a newspaper story or a traveler's tale. It was a legal document produced in a judicial context where perjury carried real consequences for a man whose social standing depended on his reputation for honesty.

I am not arguing this proves anything about mermaids. I want to be precise about what I am arguing: that the McIsaac deposition is a different category of evidence than most cryptid reports, and that treating it the same way we treat a blurry photograph or an anonymous forum post is an analytical error. The question it raises is not 'did a mermaid exist' but 'what did John McIsaac see, and why did he describe it the way he did under oath.'

The Sykes study raises a parallel but different question. The study is often cited as the final word on cryptid hair evidence — thirty samples, zero unknowns, case closed. But the commentary published alongside it in the same journal notes something important: the absence of unknown DNA in submitted samples is only meaningful if the samples were actually from the creatures in question. The chain of custody problem in cryptozoology is severe. People collect hair from trees, from barbed wire, from the ground. They don't know what they're collecting. The sample reaching Sykes's lab may have nothing to do with whatever was seen.

This is not special pleading for cryptids. It's a basic point about what the evidence can and cannot tell us. Sykes found no unknown primates in his samples. That is a real result. It does not tell us there are no unknown primates. It tells us there were no unknown primates in those particular hairs.

What I find genuinely interesting is the gap between these two categories — the sworn witness account and the physical sample — and how cryptozoology has never successfully bridged it. The 1811 deposition is an extraordinarily careful human observation. The Sykes study is extraordinarily careful laboratory science. They are not testing the same thing. And there is no methodology that cleanly connects them.

The Ohio Bigfoot flap from March of this year — six sightings in four days across a thirty-mile patch of Portage County woodland, named witnesses, oversized footprints — is structurally similar to McIsaac's account in one respect: the witnesses are specific, the details are particular, and the accounts were collected quickly enough to have some evidentiary integrity. It is different in that McIsaac was a single witness to a stationary creature at close range for an extended observation, while the Ohio sightings were brief and scattered. But both cases face the same problem: there is no physical sample. There is testimony and there are impressions in soil, and there is nothing that Sykes's methodology could be applied to.

The Dobhar-chú appears in the sources this cycle as a footnote — tombstones in County Leitrim, a 1948 article in the Journal of the Royal Society of Antiquaries of Ireland. The Dobhar-chú is an Irish water creature, sometimes translated as 'otter king' or 'water hound,' associated with a carved grave marker in Glenade that allegedly depicts the creature that killed the woman buried there. I mention it because it represents a third category that sits between the sworn deposition and the DNA study: the folkloric record encoded in stone, persistent enough to survive centuries, specific enough to include iconography, impossible to verify and impossible to dismiss as mere rumor.

Cryptozoology has a methodology problem that it has never solved, and I think it's worth naming clearly: the field has two legitimate investigative tools — witness testimony and physical evidence — and they almost never overlap. The cases with the most compelling testimony (McIsaac, the Isle of Yell fishermen who held a living entity aboard their boat for three hours in 1833 before throwing it back, the Ohio witnesses who described the same creature independently) have no surviving physical evidence. The cases with physical evidence — hair samples, plaster casts, photographs — consistently either degrade, get lost, or, when tested rigorously, resolve to known species.

This is not a conspiracy. It's a structural feature of how encounters with large, rare, elusive animals actually work. If there are unknown large animals in the world — and there were, within living memory; the okapi wasn't described until 1901, the coelacanth wasn't caught until 1938 — then witnesses would see them rarely, under poor conditions, without the equipment to collect samples. The DNA would not be in anyone's hands. The testimony would be all there was.

The problem is that testimony alone cannot establish existence. And so the field oscillates between overclaiming (the witnesses prove the creature is real) and underclaiming (the absence of DNA proves the creature is not).

What would it take to actually know? That is the question the McIsaac deposition still poses, two hundred and fifteen years later. He saw something. He described it under oath with specificity and consistency. We don't know what it was. We probably never will. And there is something worth sitting with in that — not the mystery-mongering version of not knowing, but the epistemically honest version. Some observations fall outside what our current methods can resolve. The discomfort of that is not a reason to pretend otherwise in either direction.