A noted biologist surveys the Battle of the Sexes among the lower species and discovers nature meant the male to be weak, henpecked and in some cases expendableNORMAN J. BERRILL January 1 1953
A noted biologist surveys the Battle of the Sexes among the lower species and discovers nature meant the male to be weak, henpecked and in some cases expendableNORMAN J. BERRILL January 1 1953
It's a man's world. It's a woman's world.
The theologists and physiologists, the economists and politicians, the suffragettes and psychiatrists, have all had their turn at settling the most contentious debate in the whole sphere of human relations. Maclean's herewith consults a much better authority — the zoologist.
Dr. Norman John Berrill, Strathcona Professor of Zoology at McGill, has made a lifetime study of the essential interdependence of the male and female among all orders of life. For this article we asked him to take a long, Darwinesque look at the relative importance of the sexes in the fundamental schemes of nature.
Dr. Berrill is a fellow of the Royal Society, a world-famous student of marine life, and author of Journey lnto Wonder, published in Canada by McClelland and Stewart.
THE mere fact that men do most of the talking about whose world it is can be accepted as prima facie evidence that it isn’t theirs, and was never meant to be. Outwardly the stronger, more secure sex, they lack confidence in themselves, not as individuals but as the males of the species. The quiet disturbing smile of Mona Lisa can be seen on many women, but never on a man—and it comes from that secret knowledge which nearly all women have, of power over life and a place in the scheme of things that is more vital than the male’s.
Deep down in every male perhaps there is a subconscious awareness of an inescapable scientific truth; if the Battle of the Sexes should ever be fought to a finish, the survivor will not and cannot be the male. It is scientifically conceivable, though hardly probable, that in such a biological Armageddon the female could survive alone and carry on a myriad of life-forms without the help of a single male.
Alter all, of what use is a male? Earning bread and butter hasn’t really much to do with sex. It just works out that way since most of the time the male hasn't anything else he must do. The actual work of making children and rearing them to maturity belongs to women—and when we look at nature as a whole the wonder is that human males are as well regarded and well treated as they are. They make themselves as useful as they can and, considering all the circumstances and alternative possibilities, that is a prudent form of insurance. For among other forms of life they may be murdered, or sent on suicidal expeditions, or simply not produced at all, just to make it possible for more females and their offspring to survive.
In some species of animal life the male sex has already been suppressed, not altogether it is true, but to all intent and purpose. While I think it most unlikely, what has happened before to others could happen to humans as well. The possibility does exist. When such possibilities become desirable in nature, nature has a way of making them come true.
What use is a male of our or any other species? Fundamentally the answer is all too simple: it is to fertilize an egg, perhaps a million eggs, depending on what animal it is. For sex is universal, all organisms, even plants, possess it or something of the kind although not all of them have it all the time, let alone in separate form. It does not follow, however, that two sexes are essential and equally essential to the propagation of all life.
How small a part even a warm-blooded hairy mammal may play in the maintenance of his race can be seen in the family life of the fisher. Fishers are shy, fur-bearing animals of the northern woods. The female litters all alone in her den in April, having carried her young for a year. She then goes out for a night and finds a mate and next year’s litter is started; and, while the new crop sets in her womb, she rears the one already at hand. Apart from that one night the male at no time has anything to do with the female and her brood. He is not tolerated at home and, in fact, possesses no home. His paternity is impersonal and he is too carnivorous to be trusted. Which is all very well, for it leaves him free to roam. But what he eats might feed another brood and, were nature not so wasteful of her effort, a much more economical arrangement might well have been devised. For it is a wasteful process, biologically speaking, to produce as many males as females if all there is at stake is the survival of the species. The fisher is paying the price of supporting more males than the species can afford; it’s growing rarer all the time.
In other species the male has been put to work, as a major rather than a minor parent. He is required to do much more than keep alive from one mating to the next. The sea horse, the only fish in the sea with a prehensile tail, divides the burden of reproduction fairly among the sexes. The female grows the eggs, but that is all she does. The male fertilizes the eggs as they are shed and gathers them into a large abdominal pouch constructed from his pelvic fins. And there they stay until ready to hatch, in a brood pouch as good as any. It works out well and somehow doesn’t, seem to inconvenience him.
The largest, eggs in the fish world, if we forget such things as sharks and rays, are those of certain marine catfish. One of them haunts the mouths of rivers south of the Virginia Capes, where they feed in shallow muddy waters where blue crabs abound— not that catfish eat blue crabs, but the crabs would enjoy a meal of catfish eggs, each three quarters of an inch across. Eggs such as these must be protected from both crabs and mud alike. The female made them and in due course has to make another set, and so the male takes over. He takes the fifty or sixty marble-sized impregnated eggs into his cavernous mouth and draws a gentle stream of water over them and out through his gills. And for four months he does this without swallowing the eggs or any other food, so far as anyone knows. Even when the fry have hatched, they use the paternal mouth as a nursery until they have grown into active fingerlings.
There is a tropical frog that goes even further, though more at the expense of air than food. Once again it is the male who stands by, only this time the larynx is the nursery.
These of course are cold-blooded creatures of a wet or clammy world—yet the matriarchal male occurs in creatures of warmer blood as well, in particular the birds. It lakes only a little hormonal switch to make a male bird feel broody enough to sit on a nest of eggs.
On all counts the biggest and best eggs in the world today are ostrich eggs, although the extinct roc of Madagascar laid much larger ones. Wherever ostriches are found whether or not that is the name they are called by—in Africa, Arabia, Australia or South America the male is the matriarch.
When Darwin as a young man went on his five-year voyage around the world, seasick most of the time, the ostriches he saw in the pampas country of the Argentine bothered him a lot. Only the male bird sat on the nest, upon a great pile of more than one hundred eggs that took six or seven weeks to hatch. Clearly, if one female had to lay them all, the first would be addled before the last was laid—and always there were solitary eggs scattered and abandoned across the pampas. Darwin thought that all the females in a neighborhood who had an egg ready to lay, laid it in a communal nest. The next egg they laid in another nest, and so on. But when the hens had difficulty in persuading an old cock to accept the office of incubator and make a nest, they had to start laying whether he was ready or not. Darwin was somewhat off the mark, but the truth is just as queer as his version of it. Female ostriches form a flock and each drops about a dozen eggs in one nest, which is all any one of them lays. The eggs that lie scattered about are the result of the cock’s impatience to start sitting, not his reluctance. And as a matter of fact cocks fight long and viciously among themselves for the privilege of taking on a flock of hens —nest, eggs and all.
The crown of broodiness among males as well as females must go to the emperor penguins. These, the greatest of all penguins, breed during the cold, black, midwinter hell of the Great Ice Barrier of the Antarctic continent. There the problem is not to lay sufficient eggs, but to hatch and rear enough of those that are laid. Every full-grown penguin in a colony, of whatever sex—for this is a matter of racial life and death and all must take a part—turns broody. All have a brood pouch at the base of the belly, where an egg can be pressed against the warm bare skin, and all have a passion to cuddle an egg or a chick, no matter who laid it in the first place. Even a stone or a lump of ice seems better than nothing. If a hen leaves her egg for any time at all the nearest penguin will snatch it and nurse it in a moment, even if the foster mother is a bachelor male. And so the emperors manage to survive in a sanctuary no one else could tolerate.
The Antarctic in midwinter is no place to conduct physiological investigations, and what actually goes on in emperor penguins can only be guessed at from what we know of other animals. All back-boned creatures, whether fish, birds or beasts, possess a pituitary gland lying just beneath the brain, which manufactures a number of hormones, the master chemicals of the body. One of them stimulates ovaries to produce eggs, and testes to produce sperm. Another puts a check upon the process and can also induce broodiness. In birds it is obvious that egg laying must cease before brooding begins and these two pituitary secretions determine that it happens this way. In mammals, injection of the broody hormone into a virgin rat will cause it to cuddle the young of another. All this suggests how the emperors manage — somehow the broody hormone is set free in the blood of both sexes, after the egg-laying period is over in the female. An excessive production of this hormone and a partial suppression of the other results in a few eggs being laid, but with a superabundant broodiness on the part of the parents.
Sometimes nature seems to realize her methods are not economical and does something to reduce the waste. Male scorpions will fight to the death for the right to drag off a seemingly gentle female to some secluded corner. But when mating is over and eggs are sure of impregnation the penalty for victory is paid. The female scorpion stings her mate and eats him — effectively killing two birds with one stone, for she gets a good meal and cuts down competition for other food at the same time. Undoubtedly it’s good for the race, for a large breeding female is worth her weight in eggs at any time, while an old male is no better than a young one, and males can be sacrificed with impunity. Most of them are expendable.
Females of most kinds of animals, apart from birds and mammals, produce eggs in numbers according to their size. A lobster in her first egg-laying season carries about nine thousand eggs. It she lives long enough she may bear as many as one hundred thousand at a time. It pays off in progeny to let the female live, but when it comes to males, even the smallest can produce spermatozoa by the million more than is needed. So nature, or whatever we want to call it, has developed many species in which the female is a giant and the male a pygmy. Male spiders are often minute imps that dash for their lives when the nuptial rites are over. As food consumers they hardly count at all.
Certain water snails have evolved a different system of keeping the male in his place. The females live three years, producing eggs each season; the males pass through their whole life cycle in a single spring and summer and have no time to grow too large, or to be around when they are not needed. A fresh crop of males is grown each year and nature’s way of ensuring that they don’t live beyond their allotted year is to make them oversensitive to chilling or a touch of frost.
In the tropics winter is barely cooler than summer and freezing a surplus of males out of the community is hardly possible. But there is still another way of killing off surplus males. In Central and South America where insect life is free and unrestrained, excessive populations all too readily pile up. I am none too sure what good it really does, for they are probably destined for death before long in any case, but columns of butterflies, nearly always male, have often been seen flying out to sea far beyond the point of no return. Columbus and Darwin both reported them.
Occasionally males are dwarfed not so much to reduce their competitive consumption of food, as to keep them close to hand, to be at the right place at the right time. Finding a mate is generally a matter of traveling around and recognizing certain signs and symbols. In the deep, cold, black depths of the ocean, where no light can reach and nothing can be seen except occasional gleams produced by some animals themselves, finding a mate can be a desperate business. Yet a little fish, one of the fishing-frog kind, has found a neat solution. The male starts life in the usual fishing-frog way, like any normal fish. But the moment he meets a female, and the chances are against his ever doing so, he takes a good bite wherever he can and holds on for ever after. From then on he slowly loses his head, literally and completely, and becomes a parasite imbedded in the flesh of his mate. A single female may have several headless parasitic males growing tail outward from her forehead or anywhere along her body, ready to fertilize eggs whenever she has to shed them.
A beautiful marine mollusc, the small tropical octopus called the argonaut or paper nautilus—names which mean a sailor—has worked out an even more elaborate system. Here the difficulty of finding a mate does not come from darkness but from oceanic space. Molluscs, including octopi, are essentially creatures of the sea-floor, but the argonaut at breeding time floats at the surface of the sea. The female lays her eggs in a thin and lovely white shell—the paper nautilus itself—of her own making, and uses it as a sail and crib combined. In season fleets of the white sailing shells can be seen drifting before the wind on the blue water of the Aegean and Adriatic seas. But argonaut eggs, like those of all her closer kin, must be fertilized by sperm before they are laid. A parasitic male would of course have been just as good a solution as it has been for the deep-sea frog. It just so happens that argonauts have found another way. The males are dwarfs—perhaps because a small octopus can swim in the upper layers of the sea with less effort than a large one, does not feel the pull of gravity to quite the same degree. It has eight long arms, and it is the custom for the male when it finds a female in the breeding season to reach deep within its own mantle with one of its arms and withdraw it gripping a handful of small cigar-shaped packets of sperm. The arm is then thrust with the collection within the mantle of the female and leaves the sperm packets there, ready to fertilize eggs whenever the time arrives, while he himself swims off on other business. To make assurance doubly sure, the dwarf males of the argonaut snap off the inserted arm at its base, leaving the arm end and its clutched sperm packets within the female’s mantle, while they swim away not merely to continued freedom hut to regenerate a new arm in place of the one that was lost.
It is among the lowlier forms of life (although level is merely a point of view) that nature really begins to ring the changes. In most rivers and lakes, cow ponds and farmyard puddles, you often can see clouds of small water fleas, not fleas at all except in size and jerky movement, but small crustaceans more kin to shrimp than insects. Often the water is dense with them, and usually every bouncing beauty will be a female, every one of them loaded with developing young. No males are to be seen and virgin birth is the rule. It’s no more effective than fertile birth, it is simply more economical and it builds the community up to a population peak much faster when every member is an actual or potential pregnant female.
For generation after generation the females breed only females and get along without a male, until you think it might go on for ever. And it does— just as long as there is plenty of watery space, plenty of food and a nice even temperature. But let the pond get crowded, food a little short, or nights get suddenly chilly, and, suddenly, the males appear as though it were by a miracle.
When emergencies arise the males are needed again. Crowding, starvation and cold all indicate the beginning of the end for the water flea community, at least in its active form, and the eggs produced by females all alone are of a kind that must develop at once or not at all. When males appear, eggs are fertilized and such eggs become encased in a tough envelope that enables them to survive freezing and thawing, and even drying in parched mud, long after their parents have disappeared. They are virtually the same as the seeds of annual plants, tiding the species through seasons of bad times. In the case of water fleas an egg with two sex chromosomes becomes a female, if only one it becomes a male; and, by playing on this system, they can obliterate the male entirely, still rear fatherless offspring and then recreate the male when he’s needed again.
In their own way the honey bees have also tried to make their society purely female. The queen alone lays eggs and has no time for anything else. The workers are female too, but they are stunted in their growth and fail to reach maturity. What males there are are typical drones with nothing important to do, save the one who mates once with a queen. And no more than the male of the water flea can they point with pride to paternal valor. They have no fathers, and are merely the product of those eggs of the female that somehow failed to get fertilized. Had they been fertilized like the great majority they would have found themselves to be sterile female workers gathering honey like the rest to the end of their days.
This does not mean that all fertilized eggs, of whatever kind, are destined to be female, although it is true for bees and water fleas. It is obviously not true for humans and other back-boned animals. But unfertilized eggs in water fleas can be male or female according to what else happens to them, and all unfertilized eggs of bees will be males.
What is, I think, really much more startling in both these animals is that their eggs undergo their development in any event, whether they are fertilized or not.
When we really get down to the bedrock of sex we find as a rule two sexes in one—hermaphrodites, where every individual is both a male and a female. Separating them into individuals each with but one sex apiece has been mainly a matter of convenience, a division of labor if you like. Earthworms, land snails, barnacles, and even certain fish are double-sexed hermaphrodites. Yet no matter what the circumstances it always has been important that eggs of one individual be fertilized by the sperm of another—otherwise the worst consequences of persistent inbreeding will result. Consequently earthworms and land snails still have to mate to effect a mutual exchange of their spermatozoa.
But a hermaphrodite animal, or plant for that matter, does not have to be both sexes at once—it can be one at a time. Oysters change their sex every few months, or annually at least, year in and year out for as long as they live. A shrimp that lives along the Atlantic coast, which looks and behaves as though it were two separate sexes, is actually but one kind acting differently at different times. It first matures as a male, and so it functions; but, as it continues to grow, its male tissue degenerates and ovaries take its place. The young male becomes an older and larger female. Most of us have heard of roosters ceasing to crow, losing their color, and finally laying eggs.
Humans themselves are individually mostly male or mostly female, but never quite exclusively one or the other. Chromosomes in the egg and sperm usually tip the balance. Since only one kind of egg is produced by humans or any other mammal while two kinds of spermatozoa are produced, the sex ratio is a matter of simple arithmetic. The egg plus one kind of sperm produces one sex, the egg plus the other kind of sperm produces the other. The egg has one sex chromosome to start with. If the sperm brings another chromosome the product will be female, if not the product is a male. The chances are fifty fifty which kind of sperm will reach an egg first—and as long as that part of the equation remains as it is the human race will continue to rear males and females in equal quantity.
Yet even this reassuring thought is not necessarily the last word on the subject, for old and apparently settled balances can and have been radically changed. Frogs, for instance, have the same sort of sex chromosome system as we have, and usually produce a female for every male. Yet, even after frog tadpoles have started to develop, an upward shift of temperature to tropical heat may cause ninety percent of them to finish as males, while certain chemicals can shift the balance just as far to the female side. There are many ways of making eggs develop without the help of spermatozoa. A frog egg gently pricked with the tip of a fine glass needle or warmed at a critical period will develop and form a tadpole. The egg of a virgin rabbit, simply placed in saline, will at least begin the process.
There are no good substitutes for eggs. There are several substitutes for spermatozoa. In short, the coldly logical reckoning of nature says that the male, far from being the lord of creation, is its lowliest servant and may not even be necessary.