- You have more in common with terrible bloodsucking parasites than you thought.
This is it — excrement has hit the fan and your survival is a matter of do or die. In other words, your fight-or-flight response has kicked in.
This primal reaction to dangerous situations has helped both humans and animals stay alive over millions upon millions of years. Have you ever wondered just how far back this basic element of survival goes?
Well, scientists have — kind of. A recently published study details the accidental discovery of the fight-or-flight response in an utterly unexpected animal.
We’re talking about lampreys.
These jawless, bloodsucking terror fish are among the oldest vertebrates still alive on Earth. For the longest time, scientists figured their nerve systems were simply too primitive to process even something so basic as the fight-or-flight reaction.
Yet, a chance discovery showed that they do, in fact, have this response. Now, there’s only one question remaining.
What could these nightmare spawn possibly be afraid of?
Horror, Lamprey Be Thy Name
But let’s pump the brakes for a moment. If you’re more of an indoors-y kind of person (or just don’t care to learn about horrible animals), you might not be immediately familiar with what a lamprey is.
If so, consider yourself lucky. Unfortunately, we have to ruin your day.
As we mentioned, lampreys are among the oldest living creatures on the planet. These primitive fish have existed for roughly 360 million years and they really haven’t changed much.
Which means that they looked like they crawled straight out of your nightmares even way back in the day.
The first gross thing about lampreys is their appearance. They’re eel-like, slippery, and slimy creatures with four eyes. Yet, their most striking feature is that they have no mouth.
Well, that’s not true. They don’t have jaws, but they do have a mouth. It’s a horrible, round hole lined with sharp teeth.
That brings us to the second terrible thing about lampreys — they’re parasitic. They’ll suck onto a fish and use their horrendous teeth to cut a circular hole in its side to slurp up its blood.
Despite their horrific appearance, lampreys are actually pretty tasty. They’re reasonably common fair in England, Finland, Portugal, and Japan, for example.
You should try them sometimes and literally eat your fears. If you can get over what the thing looks like.
Not Quite so Brainless
Right, so that’s a lamprey — an ancient waterborne horror. It’s that “ancient” part that for years led biologists to believe that lampreys feel no fear.
They do scatter when something dangerous shows up, but researchers believed that was because of pheromones emitted by other lampreys. The thought the fish simply don’t have the brain parts to process the fight-or-flight response.
You see, both jaws and the sympathetic nervous system (which controls the fight-or-flight reaction) are part of a structure called a neural crest. No neural crest, no jaw, and no fight-or-flight response.
Simple, right?
Well, lampreys have just given previous scientific knowledge a middle finger they don’t have. A team of researchers started looking into other cells and neural systems in lampreys when they noticed something weird.
Having cut the terror fish open, they noticed structures that looked a whole heck of a lot like the cells of a sympathetic nervous system. A closed analysis revealed that the cells produce chemicals that get further processed into noradrenaline — the neurotransmitter that triggers the fight-or-flight response.
“Now it looks like the only thing that lampreys don’t have is a jaw,” the study’s co-author and developmental biologist Marianne Bronner told LiveScience.
Fear is Older Than We Thought
We now know that lampreys can be afraid. But what do we do with information?
Well, you now have a fun trivia fact you can tell people. For evolutionary biologists, however, this discovery is kind of a big deal because it means animals have been fighting or flying for way longer than we thought.
Previously, researchers believed that the fight-or-flight response developed around 300 million years ago. However, since today’s lampreys are pretty much the same things that lived 360 million years ago, the science nerds now have to turn back their clocks by dozens of millions of years.
It also sheds light on our own evolutionary history. After all, you, me, and the lamprey are all vertebrates, which means we all share a common ancestor somewhere down the line.
Maybe that ancestor, too, was sometimes scared. So, Bronner says that the next time you jump out of your skin because you hear a twig snap while walking down a dark footpath, think of the lamprey.
Somehow, thinking of these slimy bloodsuckers is apparently supposed to be a comforting thought.