20080925

Robert Gauldie


Otolith Ear-Stones: Reading the Runes

Otoliths are real things. Did you know that? We humans have otoliths in our inner ears. Did you even know that we had inner ears? That is how we can hear our inner thoughts. Not really. Just joking. Our otoliths are among the oldest parts of our human bodies. They are true avatars. They are the part of ourselves that even still, today, relives the strange beginnings of animal life at a distance of half-a-billion years ago.
            Animal simply means the awakening of the anima: Latin for the breath of life. Anima impellunt lintea Thraciae was the proverbial North Wind whose cold breath could sway even a Thracian. But why wind? Anima, the wind, was something that had force and direction. It went to somewhere from somewhere. This is the meaning of animal life: something that can marshal its forces to go in a particular direction. How can you go in a particular direction unless you know where you came from? Wriggling about might change your position, but it is hardly to be thought of as moving in a particular direction. Therefore, to go somewhere intentionally is to leave somewhere intentionally, and, then, to go in a particular direction. This was our first act of knowing. This was our first personal freedom; the freedom to choose our own direction. The first otoliths were devices that our forebears created that allowed a choice of direction. To choose my own direction we use as a metaphor for what we consider our most basic human rights: freedom of speech, freedom of movement, and freedom of religion. Yet in it’s most literal, physiological sense, to choose my own direction dates right back to the beginning of animal life.
            The simplest otoliths are still around. They are called rhopalia. They are tiny little crystals in cells around the umbrella of the jellyfishes. The rhopalia are balanced on a tiny mat of sensitive hair cells. Gravity, ever-present gravity, means that when the umbrella of the jellyfish and its cells tilt, then the force of gravity on the hair cells will make the hair cells bend in a different direction. There you have it. A few bending-sensitive hair cells and a bit of crystal, add gravity, and even a jellyfish knows up from down. It is behaviourally aware that the directions up, down and sideways exist. It has anima. It is now an animal.
            A half-a-billion year ago puts us in the Cambrian era. The strange creatures of the Cambrian are the oldest known directional animals, the oldest known movers in a certain controllable direction. The jellyfishes are probably older, but their equivalent of the otolith, the rhopalia, proved to be a dead-end. It has been successful enough to survive for more than 500 million years, but does not provide a sufficiently flexible tool that can go past knowing up from down. So the jellyfish was doomed long ago to a slow pulsating existence, knowing up from down, aware of direction but not how to control direction.
            Way, way back in the in the early Cambrian, long before the fishes as we know them, the rocks have preserved the remains of Haikouichthys. Not just as a single rare fossil, but over five hundred specimens of Haikouichthys have been found. We are now talking something like 550 million years ago when most of the animals around were so strange that they have been given names like Hallucinogenia. For many of these strange animals we are still unsure how all their separate fossilised parts fit together. The various combinations are so strange that all appear equally unlikely to our eyes. But Haikouichthys is to all intents and purposes a little vertebrate; surprisingly similar to what we might imagine the first little fish to look like. But this is right at the beginning, before molluscs, before the crustaceans, before the worms, before even the spider-relatives, aeons before the insects. Here at the very outset of life is a little vertebrate. I have cribbed the image of Haikouichthys from the Palaeos website. As you can see from the descriptive text on the Haikouichthys image, it has all the characteristics of a vertebrate, including paired otic capsules, inner ears! They are paired, as we might expect from the forerunners of our own ears. Located close to the primitive brain, this is the first step towards hearing. Although we do not know how their paired ears worked, we know that the vertebrate otic apparatus knows up from down, as pairs they know left from right, and situated at the anterior of the fish, they know front from back. These are animals that can move in a certain direction. It is here that we see the appearance of our first freedom: the freedom to choose our own direction.


            Between Haikouichthys and the true fishes the otolith story takes a side turn. Here we encounter another little creature that looks like Haikouichthys, but differs fundamentally. Here is a little creature that echoes Sherlock Holmes’ dog that did not bark. It is the vertebrate that did not hear. We encounter these little deaf vertebrates in the Cambrian era some 20 million years after Haikouichthys makes its dramatic appearance. Pikaia and Haikouella certainly look like the cousins of Haikouichthys except that they show no evidence at all of an otic apparatus. They have no ears. The close cousins of these little creatures are still with us today. Branchiostoma, sometimes called Amphioxus, is virtually identical to Pikaia and Haikouella and still has no ears. In quiet sandy parts of bays and inlets of seas all around the world Branchiostoma can exist in huge numbers. They are shy and elusive. All but invisible, the sand-lancets as they are commonly named, slither in and out of the sand like pale transparent leaves; gone in an instant. Perhaps it is not surprising that they are still with us today. Perhaps, like the jellyfish, they stayed with the successful form of the moment, giving up the chance to evolve in return for longevity in a mute, silent world. Content with their own small advance, they changed no more. But how do they know front from back, up from down, with not even a simple gravity detector like that of the jellyfishes? The sand-lancets have eyes. Perhaps they have organised their vision to replace the ear functions. Perhaps in doing so they sacrificed the flexibility of having ears both and eyes for stability. And stable they have remained for five hundred million years, albeit deaf, and with eyesight impaired by its double function.
            From Haikouichthys we come by strange ways, mostly still unknown to us, to the early fishes. But fish so strange we never have seen their like. Only their bones remain. But in their long-fossilised bones we can see that a great knowing has taken place. They have what we can recognise as proper fish ears. As far back as four hundred million years we can see from a cast of the inside of the skull of Kiaeraspis, an early jawless fish, that there is already a capsule for the otolith as well as the semicircular canals that the vertebrates use for tracking their angular velocity. The orbits show little Kiaeraspis (the skull is a few centimetres across) had well-developed eyes. The innervated semi-circular structures around the left and right hand edges of the skull may have been direct pressure wave detectors or perhaps voltage-sensitive electric organs. The vestibule (i.e. the otic capsule) and the orbits for the eyes are fairly large. Coupled with the pressure wave detectors and/or electric organs, this little fish was as well, or better, equipped to detect danger and prey than a modern bony fish. Many fishes still retain the electrical telepathy capability that may have been present in Kiaeraspis. Can they read each other’s thoughts? Do they have thoughts to read? Kiaeraspis certainly did not have much of a brain compared to the modern true fishes. Kiaeraspis may be comparable to modern robots that can have exquisitely sensitive sensory systems but cannot think at all.


            What was once a little crystal disturbed by gravity in the jellyfishes is now in the early jawless fishes a more complex calcium carbonate structure tossed about by the ever-changing skeins of pressure waves in the sea. They can hear sound. The fish can hear. What do they hear? Is it only fear that impels them?     Danger?    Food?    Do fishes hear friendship in the sounds of their schooling numbers? Do they hear beauty? Perhaps it is best that we do not know. It is no comfort to the eaters to know the thoughts of the eaten.
            From the fishes to us, the ear-story is well known; how we part company with the fish, firstly to the primitive amphibians and then to the first mammals. Yes. The amphibians lead to the proto-mammals, not lizards or other reptiles, but proto-mammals. The oldest animals to follow the amphibians were the Therapsids, remarkably mammal-like creatures. These mammal-like forms that lead to the true mammals also lead to the dinosaurs. The early mammals were somewhat eclipsed by the telegenic dinosaurs. Just how much they were eclipsed is hard to tell. The fossil record keeps changing with mammals that are very similar to modern mammals now reaching back into the early Cretaceous. While dinosaurs thrived in the long arid period of the late Permian, Triassic, Jurassic and early Cretaceous, the mammal like animals and the true mammals were still there. The arid conditions that favoured the egg-laying habits of the dinosaurs may have also made preservation of the mammal bones unlikely. As climate conditions shifted to cooler and wetter with more rapid cyclical weather patterns, the flowering plants outpaced the older fern, pine, palm and cycad vegetation. So the tables turned on the dinosaurs in favour of the mammal-like animals and eventually the true mammals.
            The great asteroid extinction of the dinosaurs makes great theatre. It is tailor-made for television, that great promoter of least effort ideas. It has become, along with global warming, one of the great dei ex machina of our age. But the whole history of geology has been one long battle between the gradualists and the evolutionists on one side, and the catastrophists and the saltists on the other side. In the history of geology, there is nothing new in the battle between science and the various evocations of the hand of God. As science, the asteroid idea is as full of holes as big as the one the asteroid is supposed to have made. Even as theology the great asteroid extinction hardly measures up to Genesis.
            The lungfish, amphibians and sharks stayed with the oldest kind of otolith, the one that we humans still keep, a sticky agglomerate of small crystals more or less shaped in a certain way laying on a similarly shaped bed of hair cells. The fishes, ever conservative, have opted for a shift sideways, converting the sticky agglomerate into a single rigid calcium carbonate crystal, sometimes centimetres across that would make the bending of the hair cells more controllable. But the amphibian ancestors of the mammals, ever the innovators, went for a radical change. The sound waves would bend the membrane on which the hair cells grew. It was an extraordinary choice by chance that took us from hearing noises to listening to sounds From listening to sounds it is only a small step to distinguishing speech, to perceiving meaning. When the frogs call and the wolves howl, make no mistake, their meaning is clear to those who listen. Anima became for us not just the direction of the sound waves on wind and sea, but also the directions of the meanings of the sound waves themselves. We can choose the direction in which our minds go. This is our second fundamental freedom: the freedom to choose the direction of our own thoughts.
            But what about our otoliths? Ah. Our ancient avatar. Yes, we still keep it for its ancient use. It just tells us up from down and no more, neither left from right nor back from front. It is the part of us doomed to a slow pulsating existence. Try spinning around and around. It is your otoliths that make you dizzy, that make you flop around like a jellyfish.
            Well. Is that it? Have we come to the end of our aliquot of freedoms? No. We have already started on the third freedom. This is the freedom to understand the direction of the nature of life itself. To understand the nature of something is to understand how it works: to understand its mechanics, its physics, its chemistry. With that understanding comes control. We change things because we know how they work. Our knowledge of how the genetics of rice works means that we can keep hundreds of millions of people from hunger. How many Beethovens, how many Marie Curies, how many Nelson Mandelas has our knowledge of rice genetics kept from starvation? What will happen as we increase our knowledge of life itself? No more deaths from cancer sounds like a good idea. But, of course, no more deaths from cancer means that we have the potential for no more death at all. The bad news, however, is that our aberrant, highly-organised bodies must obey the laws of thermodynamics. The more complex we are the more likely we are to break down. What we call old age is simple the by-product of the frictional load on our complex bodies. Death, to which we ascribe such powerful emotional connotations, is simply poor engineering design. Can we overcome such poor engineering? Can we overcome the irrational fear of even trying to overcome such poor engineering?
            Think about the otolith. The jellyfish still lumbers along sufficient in its primitive otolith to meet it own small ends. But the better otolith engineering of Haikouichthys provided a sense of direction, and so came the freedom to move in a chosen direction. Still better otolith engineering gave us the power to perceive the directions of thought that are in inherent in the ability to hear words, not just sounds. If the jellyfish could think, they would no doubt consider the fish impious in their use of direction instead of sticking with stability. Fish, if they could think, would view us with contempt as mere flibbertigibbets who dart around endlessly chasing thoughts instead of sticking to reliable directions. Just as the jellyfish and the fishes, we also shall think them blasphemous who dare to interfere with human genetics and re-engineer ourselves to not just accommodate new directions of thought, but the new direction of life itself.
            The otolith story provides signposts along the route that the real creation process has taken to make the dust of the earth into such a strange multi-layer cake that we call man. A layer of jellyfish here, there a bit of fish, another layer of amphibian and still more laid down between Cynodonts and Creodonts; then many jumps to the Dryopithecine apes and somewhere, ill-defined, we appear. Some of the ancient genes we may well keep but nearly all of it has been re-treaded many times until we have the shape of the past, the ghost in the shell, but everything is really new. What, then, is the bit that is truly us? We are the shadows squeezed in between the many layers: the formless meanings are who we are. Just as we squeeze our words into poems to make them mean that formless something that lies in shadow between the letters and the lines, so the us of us is squeezed between the layers and the bits of animals that we once were.
            We are too well-used to the idea that we are somehow unique and special, and unchanging. We see our selves as a separate incident to the animals around us that we farm and eat and keep to amuse ourselves. We quite like the idea that we are a special act of God; even if we deride creationists for being too literal. When we try to modify the genes of ourselves and other animals, there is always a rush of public concern that we are meddling with something outside our ken; that we are meddling in things that only the Gods can do. Our hubris will destroy us. It is only natural to find this reaction from believers in religions of creation. But it comes as a shock to find this reaction in societies that are as permeated, as utterly drenched, with science and technology as we are in the Western Judaeo-Christian culture. After all, if it were not for science and technology two thirds of us would be already dead!
            Perhaps there is a general rule here that guides our destiny. Change only occurs when something does not survive. Change is the true death, and the true life. Unchanging means that there will be no re-birth, but that longevity is paid for by un-change. The jellyfish, the sand-lancets, the fish, the meat-mammals and the apes are with us still; but still in their un-changed old form. The part of them that is us has changed, but still remains the same. In some distant time there may still be people just like us. Perhaps they will be friends, we hope, with the “others”, the new people, who will abide our clumsy selves and pity us, as we the apes do pity. And build for us reserves wherein we can farm and play, build and fight, and be content in our human manner still using our earlier-model animal parts, our ear stones included, in the ancient way. We will still rejoice in our Bach and Beethoven, Shakespeare and Elliot; but the “others”, what will they hear? Is there music truly in the stars? Are there thoughts that stretch beyond the distant boundary of our isolated Universe? What hidden meanings will they contrive among the letters and lines of their speech and their poems? What great knowing that is denied to us will there be among the “others’?
            Speaking for myself, I am tired of being part-jellyfish, part-fish, part-amphibian, part–meat-mammal. I am ready for re-engineering. Oh. I forgot to mention. The lesson from the real world of evolutionary re-engineering is that last in the queue is first of the menu; just as the jellyfish, fishes, amphibians and meat-mammals have found out. Think about that next time someone talks to you about banning genetic engineering. Of course, the GMO humans of the future are not likely to eat you. Untermenschen will be far too useful to the “others” to waste as food.




Bob Gauldie is a scientist who is reasonably well-known in the little pond of fish science (http://robert.gauldie.com). Bob has also paid his dues in the tribal world of University Administration; always an environment that encourages one to be philosophical.


 
 
 
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