WE GOT OUR FACE FROM A FISH (Jul, 1931)
WE GOT OUR FACE FROM A FISH
Nothing else is of such supreme interest as the gripping and vital story of “Lifeâ€” The World’s Greatest Mystery.” Here is the second installment of the dramatic history of man’s rise from a mass of floating jelly to the human being he now is. In a most striking manner a famous authority details the amazing facts about the molding of the human face.
What They Talked About: LAST month, Dr. William K. Gregory, world-famous scientist of the American Museum of Natural History, told Michel Mok, staff writer, how the earth and life originated. About two billion years ago the earth was torn out of the sun by the passing of another star. Slowly it condensed and cooled down. A billion years later, chemical forces created tiny bits of living jelly in the primeval puddles.
These developed into colonial cell groups, into small wormlike creatures, into air-breathing fishes. Finally, some ventured out onto dry land.
The Thrilling Story Continues: MR. MOK: Dr. Gregory, you told me in our last talk that the primitive air-breathing fishes that crawled out of the water hundreds of millions of years ago were the ancestors of man. Yet, men don’t look like fishes; at least, most of them don’t. We don’t look like any animal. Where did we get our looks? Where did our face come from?
Dr. Gregory: You got your face from a fish; in fact, you got it from a shark. But before we go further, let me ask you a question. Do you know what a face is?
Mr. Mok: The front part of a head.
Dr. Gregory: That is not entirely correct. The head, you see, consists of the brain case and the face. The forehead is part of the toppiece. Draw a line across your eyebrows over the tops of your ears, and everything under that, to the top of your Adam’s apple, is your face. Most people think the forehead is included. That is not so. If it were true, then the balder a man, the higher his face would extend. But all this does not explain what a face is. So far, we have only decided where it is. Try again.
Mr.’ Mok: Well, I might say that the face is the fortune of some and the misfortune of others.
Dr. Gregory: That answer is scientifically almost right. The face is the fortune of all animals; they literally make their living with it. Among people it is sometimes a misfortune. But that is because we have invented all sorts of new functions for the face.
Mr. Mok: New functions? What are they?
Dr. Gregory: First let’s see what the old or original functions are. The face is two things in one. Primarily, a trap to catch food. Secondly, an instrument board on which are mounted the receiving parts of several instruments of precision, such as the eyes, the ears, the nose. The purpose of these instruments is to take the owner of the face to places where he may find food to catch in his trap, and to warn and take him away from dangerous neighborhoods.
MR. MOK: That is true of animals. But what do we do with them? What did you mean by “new functions”?
Dr. Gregory: We use our faces to catch mates, play poker, make political speeches, and for a number of other things peculiarly human. Since man is the latest species of animal to arrive on earth, these uses are new. Now, if a man’s face is not adapted to one of these uses, he is, as the saying goes, out of luck. That is why it is only among people that the face may be a misfortune. An animal is never out of luck on account of its face. It always serves its purpose, except when severely injured.
Mr. Mok : But why do you say that we got our face from a fish? Last month you told me that we parted company with our cousins, the apes, about ten million years ago. I should imagine that our face came from them.
Dr. Gregory: It did. But it goes much further back than that. Suppose a man inherits a gold watch from his father, who. in turn, had received it from his father, and so on, for several generations back. Wouldn’t it be entirely true to say that the present owner got that watch from his great-great-grandfather?
Mr. Mok: Of course.
DR. GREGORY: Well, we got our face from a fish in somewhat the same way. The difference is this: When you inherit a watch, the entire, ready-made article comes down to you unchanged. In the case of the face, our earliest ancestors left us only the “works,” that is, the ground plan. Each succeeding group of animal ancestors modified it, added touches of their own, or lost some part or other.
Mr. Mok : What were these succeeding groups of our ancient animal ancestors? Dr. Gregory: Briefly, the ape got its face from the early monkey; the monkey from the opossum; the opossum from the lizard, and the lizard from a fish. You can visualize this line of succession best by picturing it as a staircase. You stand on the top step. The ape stands on the first step below you, the monkey on the second step, and so on down. But you must understand that each of the animals I named is the modern representative of great groups of numerous species that lived ages ago.
Mr. Mok : How many years are represented by each of your steps?
Dr. Gregory: The apelike creatures lived from ten to twenty million years ago, the early monkeys from twenty to fifty million years ago, the opossums from fifty to one hundred million years ago, the lizards from one hundred to three hundred million years ago, and the fishes from three to five hundred million years ago. These are not wild guesses. The length of each of these periods was established by the radium clock which I explained to you last month. So, you see, your face is quite an antique.
MR. MOK: I had no idea I owned anything as ancient as that. You mean, then, that the fishes were the first creatures that had faces?
Dr. Gregory: They were the first creatures that had anything resembling a human face. Other, earlier creatures had faces of a sort, but they were not at all like ours. They looked more like the faces of worms.
Mr. Mok: In what way does the face of a man resemble that of a fish?
Dr. Gregory: A man and a fish have the same facial outfit. The same parts are arranged in the same order. In both, the smelling part is in front of the eyes; the eyes are above the jaws; the jaws are below the brain case. The only fundamental difference is that a fish has no external ears.
Mr. Mok : I think that is only a sketchy resemblance.
Dr. Gregory: It would be if that were all. But the resemblance goes much deeper than that. The very same bones in the jaws of the fish that it uses to catch other fishes also serve us to eat it. We have inherited the bones of the tongue and of the throat from the fishes. The muscles that move our jaws and tongues are modifications of those of the fishes. The way our brain is divided into its main sections is the same as that in the fish. Now, have I convinced you that you look like a fish?
MR. MOK: Not completely. But, even granting that a man and a fish do resemble each other, I still don’t see how that proves that the fishes were our ancestors. A man may have a face like the moon; a pretty child may look like a flower. That does not prove any relation, does it?
Dr. Gregory: Of course not. And the reason it does not is that such resemblances don’t exist, except in your imagination. Real resemblance is structural resemblance. Our face and that of the fishes resemble each other in structure. Structural resemblance is evidence of descent. Mr. Mok: Why? Dr. Gregory: Because animals that are known to be related resemble each other in structure. The opposite is also true. Take, for example, the bulldog and the Russian wolfhound. On the surface, they look quite different. Yet, through their structure, the descent of both has been traced to the same wolflike animal.
Mr. Mok: But even if their structures are alike, couldn’t they have been “designed” independently, as it were? A Rolls Royce and a Packard are both automobiles. Their structures resemble each other a good deal. Still, they were built in different factories.
Dr. Gregory: Very true. However, the history of the automobile shows that they are related. They are both modifications of the same crude horseless buggy of forty years ago. Do you see the point?
Mr. Mok: I do. What I don’t see is why you singled out the shark as the particular fish that gave us our face.
Dr. Gregory: Simply because the shark is the least modified survivor of the early vertebrates, or backboned creatures. In other words, the shark has remained in the horseless buggy stage, while man has developed into a modern car. To put it a bit differently, the shark, or dogfish, to this day carries around with it the original ground plan of the human anatomy, including that of the face.
Mr. Mok : Where did the shark get its face?
DR. GREGORY: Probably from some wormlike water creature. We don’t know exactly what kind. There are several theories, but the question is still up in the air. What we do know is that the shark is much closer to us in anatomy and appearance than it is to any of its invertebrate, or backboneless, ancestors.
Mr. Mok: Very flatteringâ€”for the shark. But if we developed from the shark, why is it that the old shark is still with us?
Dr. Gregory: The present shark is a descendant of a conservative branch of the shark family. You and I are descendants of a progressive branch. In a way, it is the same situation you observe among people. Let us suppose that one hundred years ago there were two brothers, the sons of a poor night watchman. The older got ahead in the world; the other stayed poor. Today, a descendant of the older brother is the millionaire president of a large corporation, while the great-grandson of the other is still a night watchman. Is that clear?
Mr. Mok: Yes, but what was the cause of the split among animals?
DR. GREGORY: Nobody knows. We do know, however, that in every age of the history of the earth, descendants of the conservative and progressive branches of the same old animal families have lived side by side. Mr. Mok: How do you know? Dr. Gregory: Geologists have found fossils of both kinds in one rock layer; that is, a rock layer formed during a definite period in the history of the earth. All of the rock layers that have been examined, each of them formed during a different period, have yielded such “conservative” and “progressive” fossils. Mr. Mok : Then the shark, you might say, is a fossil that has survived? Dr. Gregory: Exactly. As a matter of fact, we call it a “living fossil.” The opossum is one, too. They are animals that have not progressed in hundreds of millions of years. A little while ago, I compared the shark to the old horseless buggy. But there is a difference. The first automobiles are no longer in use. They are on exhibition in museums, as curiosities. The living fossils, on the other hand, are like horseless buggies that are still running around, side by side with the Rolls Royces and Packards that sprang from them. Do you see now how it is possible that the shark, in a manner of speaking, could develop into man and stay with us at the same time?
Mr. Mok : I see that it could happen, but not how it happened. To come back to the face: how did it develop from the hideous mask of the shark into the human countenance?
Dr. Gregory: To understand that, you must first realize that every feature of the fish’s face is adapted for helping the fish make its living in the water.
Mr. Mok: In what way?
Dr. Gregory: In three ways. First of all, it is streamlined so that it creates a minimum of turbulence in the water and a maximum of ease in slipping through it. Secondly, it is slippery.
Mr. Mok: What makes a fish slippery?
Dr. Gregory: It is covered with a lubricant. This is a mucus, or slime, which the fish itself manufactures. The purpose of this jellylike stuff is to dissolve the tiny parasite water plants and animals that otherwise would fasten themselves onto the fish’s body, like barnacles to the bottom of a ship, and hinder its movements. We owe our own skin, including that on the face, to the inner layers of the fish’s skin.
Mr. Mok : A good thing we picked the inner ones, or we would be covered with scales.
Dr. Gregory: There was nothing else for us to pick, as you put it, for the fishes gradually lost the outer layers of their skin, including the scales, when they crawled out of the water and became land-living animals.
Mr. Mok : You have mentioned two of the features that helped the fishes to make their living in the water. What is the third?
Dr. Gregory: The third is very important. It is their elaborate system of gills, supported by beautifully jointed arches and levers. This enables the fishes to breathe in the water.
Mr. Mok : I know. But where is the connection with human beings? We don’t live in the water, and don’t need gills. We breathe through lungs.
Dr. Gregory : Here is the connection: In our own heads, a part of the remains of this gill system forms the larynx, the box on which our vocal chords are stretched. Another remnant of it is our thyroid. This is the gland, located right under the Adam’s apple, which makes one of the chemicals that regulate our growth. Still other remnants of the gill machinery are our tonsils, and the glands that make the saliva. The larynx, or voice box, is derived from one of the fish’s gill arches. The thyroid, the tonsils, and the salivary glands were originally the pockets of inner skin that form the fish’s gills.
Mr. Mok: Can you prove all this?
Dr. Gregory : Certainly. The proof is this: An unborn baby, in the fourth week of its development, has no larynx, no thyroid, no tonsils, and no salivary glands. Instead, it actually has gill pockets and gill arches, like a fish.
Mr. Mok: What becomes of them?
Dr. Gregory : The gill pockets become the child’s thyroid, his tonsils, and his salivary glands. The gill arches develop into his larynx; the inner, gristly core of the jaws; and the little bones of the middle earâ€”that is, the part of the ear that transmits sound waves from the outer shell to the inner ear. As a matter of fact, the unborn baby, in its various stages, offers a very much condensed and blurred record of man’s development from the earliest forms. It has, in turn, characteristics of a one-celled creature, a worm, a fish, an amphibian, a lizard, a hairy mammal, a creature with short legs like an ape, and, finally, a man.
Mr. Mok : Why is the record blurred?
Dr. Gregory: Because the unborn baby, in each of these stages, resembles the unborn young of the various animal types, and not the adults. If it resembled the adults, the record would be much clearer.
Mr. Mok : Is there any other evidence of our fish ancestry?
Dr. Gregory: Plenty. In an adult, the heart is separated from the head by the neck. The four-week unborn baby has no neck. Its heart is located right behind the “gills,” as it is in a fish. Another piece of evidence is that we have the remains of a double skull.
Mr. Mok : You mean one head inside the other ?
Dr. Gregory: Yes, but not all the way. Many of the early fishes had a double brain box. The main purpose of the inner box was. to protect the brain and the nervous parts. The outer shell served as a shield against the water and as a base for the muscles. This is still true in many fishes and in some of the lower animals, such as lizards.
Mr. Mok: How about us?
Dr. Gregory: In us (and in the other mammals) the top of the old inner roof has thinned out and is now represented by a membrane, or thin skin, which is the outermost of the three membranes that protect the brain. The base, or floor, of the brain case still is double, and so are the lower parts of the sides of the box, directly inward from the ears.
Mr. Mok: Where did we get our teeth? Did we inherit them, too, from a fish?
Dr. Gregory: We surely did. Every time your best girl flashes you one of her pretty smiles, she displays a legacy from the shark.
Mr. Mok: Our old friend, the shark, again!
Dr. Gregory: We cannot get away from him. He is the ground plan, remember. Now, this shark was a gangster of the worst kind; a robber and a murderer. Naturally, he had thousands of enemies. To protect himself, he wore a coat of mail.- In other words, he was covered with teeth from snout to tail.
Mr. Mok: Real teeth over the entire body?
Dr. Gregory: They were real enough, though most of them were small. They were tiny, flat scales with sharp points, called skin denticles. In the skin around the shark’s mouth, they became larger and gave rise to the teeth.
Mr. Mok : Then the teeth are originally a product of the skin?
Dr. Gregory: Right. They were really enlarged skin denticles. In the beginning, teeth had no sockets. The shark still hasn’t any. Its teeth grow right out of the skin inside its mouth. This skin is rolled around over the edge of the jaws onto the inside of the mouth. The shark has practically an unlimited supply of teeth; the tooth-bearing part of its skin keeps on growing them. When some break off in front, others swing up from the rear, like reserves. The shark probably continues to grow them as long as it lives. In the primitive shark, the teeth were merely piercers to grasp and help kill its prey.
Mr. Mok: It is hard to realize that these murderous prongs developed into our teeth. How did it happen? Dr. Gregory : In later fishes, especially the air-breathing ones, certain parts of the skin that covered the jaws both on the inside and the outside produced bony plates. Bone, you know, is in a sense nothing but hardened skin. To these bony plates the teeth became attached. Later still, the teeth gradually sank into sockets in the bones.
MR. Mok : As I understand it, everything you have told me so far about the face covers its development from the fish’s original food trap.
Dr. Gregory: That is right. Mr. Mok : What of the face as an instrument board? Where, for example, did we get the nose?
Dr. Gregory: Sorry, but I will have to go back to the shark again.
Mr. Mok: I am used to it by now.
Dr. Gregory: The shark had simply two open pockets, one on each side of its face. They contained a membrane folded somewhat in the shape of a rosette. These membranes were sensitive to odors in the water, especially that of dead fish. That was the humble start of the feature that is mainly responsible for the beauty of the face of man, and the beginning of the organ that makes him delight in the fragrance of the rose and of the frying breakfast bacon. The openings of the shark’s nose were on opposite sides of the face because they presumably acted as guides in the creature’s steering.
Mr. Mok : How would the fact that they were on opposite sides help it in steering?
Dr. Gregory: Because by turning so that it gets a whiff in both nostrils, it makes straight for the source of the smell. That is one of the reasons that three of our sense organsâ€”the eyes, the nostrils, and the earsâ€” are arranged in pairs. As I said before, they are the receiving parts of instruments of precision. These instruments are really range finders. Because the receivers are arranged in pairs, they get equal impulses only when the source is directly in front of them. The same principle forms the basis of the seismograph, the apparatus used to detect the direction of an earthquake, and of several other instruments of precision.
Mr. Mok : But we have our nostrils close together.
Dr. Gregory : That started with the mammals. The reason probably was that the eyes superseded the nose as range finders.
Mr. Mok : How did the development come about?
Dr. Gregory: Between its two rather distant nostrils, the shark has a bridge of gristle covered with skin, which completes its streamline contour. This is its snout. The roof of this snout, or false face, corresponds to the bridge of the human nose.
Mr. Mok : Where did we get the rest ?
DR. Gregory: Just a moment. The later fishes had a pair of bony lids instead of the shark’s gristle-bridge. In the mammals, these nasal bones extend nearly to the front end of the snout. When you get home, take a good look at the face of your dog, and you will see that this is so.
Mr. Mok: But where did the tip of the nose come from?
Dr. Gregory: I am coming to that now. In the manlike apes, the nasal bones have become shortened in front. The tip of the nose has begun to form but it is not yet much raised beyond the surface of the face. The wings of the nose are large. As the lips and the sides of the nose drew backward, the tip grew forward and downward. How much it grows downward and forward determines what kind of nose you are going to haveâ€”Greek, Roman, or plain pug.
Mr. Mok : In the beginning of our talk, you said that we used our faces to catch mates. It would appear to me that the shape of the nose had a good deal to do with that?
Dr. Gregory: I would not be surprised. But styles in noses, like everything else, change at different times and in different places. Every Australian bushman village may have its own John Barrymore. I believe that our own ancestors of glacier times had faces that were shaped much like those of the Australian bushmen.
Mr. Mok: And what of the lips?
Dr. Gregory: Our remote ancestors, from the air-breathing, lobe-finned fishes to the primitive reptiles, had only a bony mask over their faces. This was covered with tough skin, such as the alligator has today.
Mr. Mok : Please don’t tell me that I owe part of my face to a crocodile!
Dr. Gregory : You do. The reptiles are the inventors of the beginnings of the machinery that gives your face its expression. You see, all the reptiles have a circular band, a muffler you might say, of muscles around their throats. These muscles are under the control of the so-called facial nerve.
Mr. Mok : You don’t mean to say that an alligator expresses its feelings with its neck?
Dr. Gregory: Of course not. Expression came much later. In the early mammals, this muffler of muscles has grown forward over the face and around the eyes, but it has not yet reached the place of the future lips. As these muscles grew forward, they dragged along with them the branchings of the controlling nerve, which spread over the face like a vine.
Mr. Mok: When did the lips appear?
Dr. Gregory : In the regular mammals, such as the horse, the cow, and the dog. This system of muscles and nerve branches reaches a high development in the manlike apes. They are known as the mimetic, or actors’, muscles, because they are the “tools” of the theatrical profession. In all mammals the mimetic muscles and their nerves also extend upward around the ears and scalp. Every one knows how easily animals can move their ears. Among us mortals, only a few gifted individuals have inherited that talent.
Mr. Mok: Did we invent the smile?
Dr. Gregory: No. The great apes laugh, grin, and smile, but their “smile” may mean anger. When they raise their upper lip so that they expose their canine teeth, they are angry. Otherwise, it means laughter. As for the “smiles” on the faces of cats and dogs, I suspect that they do not exist, except in cartoons.
Mr. Mok: Do the apes kiss?
Dr. Gregory: Not exactly. The mother chimpanzee bends over her baby and touches it with the tip of her lower lip. But it is not a completed kiss. The apes use their lips as touch organs to explore things, especially things to eat, and as a funnel through which they suck fruit juices.
Mr. Mok: Where did we get our ears?
Dr. Gregory: The external ear- openings appeared first in the lizards. The outward ear is simply a resonator, or tube, to catch sound vibrations. The lower mammals were the first animals that had it. In the beginning, it was just a fold of skin, supported by gristle. In the higher mammals, it was seized hold of by the mimetic muscles, so that these animals can move their ears in almost any direction. The ear shells of certain apes are so much like ours that you can scarcely distinguish them.
Mr. Mok: And the eyes?
Dr. Gregory : This time I have to go back further than the shark. The first little wormlike creatures had eyes of a sort. They were merely spots of pigment, sensitive to light, that enabled their owners to distinguish between light and darkness. Like teeth, the eyes are originally a product of the skin. In the primitive sea creatures, they may occur in almost any place on the surface of the body, and sometimes in great numbers. The fishes were the first to have eyes somewhat like ours.
Mr. Mok: How do they differ?
DR. Gregory: Their eyes consist of the same three main parts as oursâ€”the lens; the cornea, which is the horny, transparent skin in front of the eyeball and pupil; and the retina, which receives the images, like the film in a camera. But in the early fishes’ eyes, the cornea is flat as a protection against the water and also because a bulging eye would interfere with swift movement by increasing the resistance. The principal difference, however, is that their eyes point forward and outward. The eyes of all lower animals do. Ours point forward but not outward.
Mr. Mok: What is the effect of this shift in position?
Dr. Gregory: It gives us our bifocal, stereoscopic vision.
Mr. Mok : Have we a monopoly on that ?
Dr. Gregory: Oh, no, the early monkeys began the invention. A few other animals, such as the cat and the owl, had a try at it, but it was not very successful.
Mr. Mok : Where did our eyelids come from ?
Dr. Gregory: The eyelid began as a skin over the eyes of the fishes, but it did not become a sensitive, movable eyelid until the mammals appeared. The shark has a horizontal eyelid which is drawn across the eye like a shutter. You still carry a remnant of it around with you.
Mr. Mok: What is that?
Dr. Gregory: The little red spot in the corner of your eye.
Mr. Mok: Do animals cry as we do?
Dr. Gregory: You mean weeping, don’t you ? The tear ducts and their glands made their first appearance in the land-living animals and were developed fully by the mammals. Essentially, it is a lubricating apparatus to keep the eye moist and clean. But the animals do not weep as we do.
Mr. Mok : I suppose that finishes the features of the face?
Dr. Gregory: Yes, that covers the face of a man pretty well, unless he has a full set of whiskers. If he has, he got it from the mammals, as he did his hair, his eyebrows, and his eyelashes. But don’t forget that a face, whether it is bearded or clean-shaven, handsome or homely, is only one “exhibit” in a museum.
Mr. Mok: A museum?
Dr. Gregory : Yes, man is a museum. I will explain that to you in our next talk.
NEXT MONTH: Dr. Gregory will show that the human body is a museum. In tracing and explaining its part-by-part development through the ages, he will take up the fascinating question of Man’s descent from the apes, and will offer indisputable proof of our monkey ancestry. It will be an outstanding installment in this gripping series, which is to be continued by Dr. Gregory and other world-famed scientists.