Part 6

Similarly with variation, the demands of his hypothesis are very slight. If it be conceded that variation is a fact, that offspring do vary from their parents and each other, it is enough. And who will dispute this in a world where no two creatures are exactly and in all particulars alike? The apparent contradiction that, heredity demands likeness, while variation requires difference, is confined to the surface--it is not real. The likeness is general while the difference is particular. A sheep may be born with shorter or longer legs, by variation; but it will be a sheep and not a horse, by heredity.

As an example of the working of the theory let us take Lamarck’s piece de resistance, the giraffe. Lamarck says: “We know that this animal, the tallest of mammals, inhabits the interior of Africa, and that it lives in localities where the earth, almost always arid and destitute of herbage, obliges it to browse on the foliage of trees and to make continual efforts to reach it. It has resulted from this habit, maintained for a long period in all the individuals of its race, that its forelegs have become longer than the hinder ones, and that its neck is so elongated that the giraffe, without standing on its hind legs, raises its head and reaches six meters in height (almost twenty feet).”

Lamarck thought this length of neck was acquired by “continual efforts to reach,” or, as Alfred Russell Wallace puts it in his criticism of Lamarck--“stretching.” Many critics ventilated their wit on this theory of Lamarck’s, under the impression that they were lampooning Darwin’s idea.

They made a blunder similar to that of those critics of Utopian Socialism who labor under the pleasing delusion that they are riddling the theories of Marx. Professor Ritchie has preserved a couple of stanzas by a witty Scotch judge who aimed his poem at Darwin, but hit Lamarck.

“A deer with a neck that was longer by half Than the rest of his family, try not to laugh, By stretching and stretching became a giraffe Which nobody can deny.

That four-footed beast which we now call a whale, Held his hind-legs so close that they grew to a tail, Which he uses for threshing the sea, like a flail, Which nobody can deny.”

But Darwin’s theory is altogether independent of the “stretching” idea. The causes and origin of heredity and variation are up to this moment, alike wrapped in mystery. But when science succeeds in penetrating those secrets, it is extremely unlikely that Darwin’s theory will be seriously weakened, no matter what the causes may prove to be.

Now about the giraffe. We will suppose, for the sake of illustration, two giraffes, a male and a female, whose necks are precisely five feet long. We will confine our illustration to the question of the neck alone. We will suppose this particular pair to give birth to a family of three. First comes heredity. All we ask of heredity is that the young shall be giraffes, not camels or any other species; and this heredity guarantees. Now comes variation. As this is an ideal case for the purpose of illustrating the theory, we will have one of the three shorter-necked than the parents, another the same length, while the third has a longer neck--over five feet.

Now comes the struggle for existence. When this family of giraffes is fairly grown and the new-comers are approaching breeding age--mark the importance of this matter of “breeding age,” for the problem is to find out how nature determines which shall be bred from--they are obliged to forage for themselves. There is no pasture to graze; they live in what is almost a desert. There are few shrubs; scarcely anything but fairly high trees--from ten to twenty feet. If a giraffe breeder had this matter in hand and he wished to increase the length of the giraffe’s neck, the problem would be simple. He would select number three with the longest neck, pair it with the longest necked member of the opposite sex in some other family and the trick would be done. But this is in Central Africa, where there is no breeder to interfere, and the question is: can nature accomplish the same result without his help?

This is what happens. First the leaves are eaten from all the lower branches as they are reached with the least effort. Then they go higher and still higher until the point is reached where number one with the shortest neck cannot reach any further and the terrible struggle for existence begins. Number two sees no danger as yet and number three has things all his own way. But with short-necked number one, a tragedy has begun. Every day now sees the food further out of his reach and even number two is obliged to reach out for his supply. The breeding time is approaching but the longer necked and therefore well-fed and vigourous females will have nothing to do with this wobbley starving creature, and the longer necked, well-fed males shun the short-necked starving females. If the starving ones mate, the mother dies before giving birth to offspring, or she cannot get nourishment enough to rear her progeny; in either case there is no effective succession. So the longer-necked are the fittest and they survive. Thus does nature “select” one by the negative process of destroying the rest, in about the same way as a man “selects” one puppy in a litter by drowning the rest.

In the case of the puppies we may say “artificial selection;” in the case of the giraffe it is “natural selection.” And this theory, simple as it may seem here, revolutionized Biology.

It is worthy of note that “natural” selection has many advantages over “artificial” selection. The breeder may be mistaken; he may select the wrong puppy and drown its superior. The horse that won the great race may have had a fleeter-footed companion in the same stable had the trainer known how to develop his possibilities. The gardener may have passed the best root or stem through carelessness. But nature makes no such mistakes, or if she does she eventually redeems them. Her method, while it is wholly fortuitous and unintelligent, is practically infallible. The condition of survival is, adaptation to environment. The very process of selection is, in itself, a sure test of fitness. True, moral considerations are eliminated--at least in the non-social world--yet nature offers something like a fair field and no favors. When we speak of nature’s favorites, we simply mean those who are best fitted to meet her hard conditions.

Take a row of celery plants, from which future seedlings are to be “selected.”

In this instance, let us suppose, the quality desired is ability to resist frost. How is the gardener to know which of fifty plants are the “best” in this respect. He has no method of finding out with any degree of certainty. But nature comes along some night with a sharp frost and “selects” ten by killing forty. And the very act of this “natural” selection proves that these ten are better able to withstand the frost than their fellows.

Breeders of white sheep who supply the white wool market have a very tangible guide--they kill every lamb that shows the least tinge of black. But even here, nature is not to be out-done. In Virginia there is--or at least was in Darwin’s day--a wild hog of pure black. One of its staple foods was known as the “paint-root.” Any hog with the least speck of white on its body was poisoned by this root while its all-black brothers found it a health-sustaining and succulent food.

In an environment which remained constant and where a species of animals had reached a population which strained the limits of subsistence--food supply--those offspring which most closely resemble their parents, who had won out in that environment, would again succeed and be selected. While if the environment changed--became warmer or colder for example--those descendants which happened to vary in a direction making them better able to cope with the new conditions would be selected for survival as against those who resembled their parents, which parents had survived in their day because they were adapted to the prior environment.

For example, a country is well supplied with water and it is as a consequence fertile and “green.” In such a country green insects and green reptiles will be selected, because a green background will render them almost invisible to their enemies. Individuals of other colors will make their appearance by variation, but they will be such plain targets to their enemies, they will be devoured before they reach breeding age and have a chance to reproduce the variation.

But suppose desiccation (drying up) sets in. The country loses its water supply, as Krapotkin has shown to have been the case in North-West Mongolia and East Turkestan, leading to the enforced exodus of the barbarians. Now green will disappear and brown or yellow--say brown--takes its place. While this change will not, so far as we know, cause insects and lizards to breed brown instead of green, it will ensure the survival or “selection” of such as are born brown and the destruction of those who breed true to their green ancestors. Now every atavistic return to green will be mercilessly weeded out, just as, when the country was well-watered and green, every sporadic production of brown was done to death.

This is the biological foundation of that environment philosophy which now pervades all our thinking. Change the physical environment, says the biologist, and the species will be transformed. Change the economic environment, says the Socialist, and, if you make the right change, the race will be redeemed. Both statements rest on the same fundamental laws.

As the many and highly important implications of this theory, are fully dealt with in subsequent lectures most of them will be passed here.

We may note however, that whenever any nation in the modern world, produces, in the development of its industry, a Socialistic variation, that new feature at once proves its utility and is “selected” in the Darwinian sense, because it constitutes an advantage over the previous form of social organization, in that particular. This is the reason why the trust--which is socialistic and revolutionary in its essential tendences--is always victorious, in spite of the foolish ravings of the Hearst newspapers and the antediluvian twaddle of William Jennings Bryan.

But Darwin’s crowning achievement is that he made the general theory of evolution impregnable by thoroughly and conclusively demonstrating it in his own field as a naturalist. From then on it was only a question of time as to when its application would be universal.

Socialism may be defined as the application of the theory of evolution to the phenomena of society. This is precisely what Marx and Engels accomplished, and this why their work is so fundamentally opposed to the conventional theories and theological superstitious current in their time, and so fully in harmony with all the latest achievements in the scientific world. History ceases to be a meaningless mass of war and famine, bloodshed and cruelty. It becomes a panorama presenting the development of society according to laws which may be understood and with a future that may be measurably predicted.

It develops by the operation of forces that no man or class can wholly stay or hinder. The power of those forces and the direction in which they are now making has been well set forth by Victor Hugo by a very striking simile in the following passage:

“We are in Russia. The Neva is frozen. Heavy carriages roll upon its surface. They improvise a city. They lay out streets. They build houses. They buy. They sell. They laugh. They dance. They permit themselves anything. They even light fires on this water become granite. There is winter, there is ice and they shall last forever. A gleam pale and wan spreads over the sky and one would say that the sun is dead. But no, thou art not dead, oh Liberty! At an hour when they have most profoundly forgotten thee; at a moment when they least expect thee, thou shall arise, oh, dazzling sight! Thou shalt shoot thy bright and burning rays, thy heat, thy life, on all this mass of ice become hideous and dead. Do you hear that dull thud, that crackling, deep and dreadful? ’Tis the Neva tearing loose. You said it was granite. See it splits like glass. ’Tis the breaking of the ice, I tell you. ’Tis the water alive, joyous and terrible. Progress recommences. ’Tis humanity again beginning its march. ’Tis the river which retakes its course, uproots, mangles, strikes together, crushes and drowns in its waves not only the empire of upstart Czar Nicholas, but all of the relics of ancient and modern despotism. That trestle work floating away? It is the throne. That other trestle? It is the scaffold. That old book, half sunk? It is the old code of capitalist laws and morals. That old rookery just sinking? It is a tenement house in which wage slaves lived. See these all pass by; passing by never more to return; and for this immense engulfing, for this supreme victory of life over death, what has been the power necessary? One of thy looks, oh, sun! One stroke of thy strong arm, oh, labor!”

IV.

WEISMANN’S THEORY OF HEREDITY.

The weak, untrained brain must have a conclusion. It cannot reserve its decision or render an open verdict. It is completely at sea in the scientific world where the most profound savant is often obliged to say, “I don’t know.” In a crowded courtroom, ninety per cent of the spectators have made up their minds that the prisoner is innocent or guilty before the first witness is called or a line of the evidence has been read. He has a square jaw, or bushy eyebrows, or thick lips, or he shifts uneasily from one foot to the other, any or all which proves to the simpletons back of the rail, that he must be guilty no matter what the crime is, or what the evidence may be. If he has blue eyes and fair hair and mustache, or a pleasant manner, or pretty hands and the onlookers were to decide the matter, they would hardly convict him on his own confession. In England, a judge is not placed on the bench because he “stands in” with a ward boss, but because of his wide scholarship and systematic training, and the reason advanced for this method is, that only a scientific scholar can reserve his opinion until all the evidence is in and then, if the case demands it, render an open verdict.