DARWIN AND THE TRIUMPH OF EVOLUTION
The outstanding figure of the entire history of evolution is Charles
Darwin. Whether or not he deserves all of the prominence that has
been given him is a question--a question that probably must be
answered in the negative. We are very apt to lionize the victor while
we ignore those who made the victory possible, whether it be won in
science, politics, or warfare. Among certain circles today there is
an undeniable tendency to over-praise Darwin; to talk and think as
though he were the first and the last truly great evolutionist. It is
becoming with Darwin as Harris found it with Shakespeare: “He is like
the Old-Man-of-the-Sea on the shoulders of our youth; he has become
an obsession to the critic, a weapon to the pedant, a nuisance to the
man of genius.” If we substitute ‘popularizer’ for ‘critic,’ Harris’
sentence will apply to Darwin without further modification. There is
a popular misconception that a great and successful scientist must of
necessity be a man of great genius; nothing of the sort is true. Take
the average “authority” away from his specialty, and he is a very
commonplace individual; take him with it, and he is often little more
than a remarkably durable and precise human machine.
Neither biographers nor critics have shown us any good reasons
for considering Charles Darwin an exceptionally great man. He was
a highly successful scientist, but at the same time he was aided
to success by the condition of science during the eighteenth and
nineteenth centuries, and his personal fortune. In this connection
it will be worth our while to examine the opinions of Carlyle, as
reported by Frank Harris. The two were discussing notables of the
century, and Harris brought up the name of Darwin. Carlyle described
the two brothers as “solid, healthy[12] men, not greatly gifted,
but honest and careful and hardworking ...” and speaking of a
conversation with Charles Darwin after his return from the “Beagle”
voyage, said: “I saw in him then qualities I had hardly done justice
to before: a patient clear-mindedness, fairness too, and, above all,
an allegiance to facts, just as facts, which was most pathetic to me;
it was so instinctive, determined, even desperate, a sort of belief
in its way, an English belief, that the facts must lead you right if
you only followed them honestly, a poor, groping, blind faith--all
that seems possible to us in these days of flatulent unbelief and
piggish unconcern for everything except swill and straw.”[13]
We need not, like Carlyle, abuse this “allegiance to facts”; it
is the foundation-stone of all reliable scientific work, and the
scientist who abandons it is sure to bring disaster to himself and
his work. And yet, to maintain that fact-hunting is, of necessity, a
mark of genius is absurd.
It is largely the qualities that prevent us from ranking Darwin as
a genius that establish his eminence as a research scientist. He is
great not for his ideas, for they had been worked out before him,
but for the clearness with which he stated his conclusions, and the
wealth of proof which he brought to their defence. The earliest
evolutionists tried to solve their problems by deduction, making the
theory first, and searching for the facts afterward. Darwin’s method
was just the opposite. As he himself says, he searched for fact
after fact, at the same time straining to keep all thought of theory
from his mind. Finally, when he had ascertained how things actually
were, and had arranged his information, he set forth to formulate a
theory that might accord fully with what he knew to be the truth.
He took the ancient, indefinite idea of evolution and welded it into
an organized theory, and armed it with an array of facts that made
it irresistible. While some of Darwin’s beliefs have failed to show
the importance he assigned them, and others of them are very probably
errors, there are few indeed who seriously, from the standpoint of
science, care to question the conception that all living things have
developed from earlier living things of simpler or more primitive
character. His careful, painstaking work gained for his ideas a world
wide acceptance among thinking men, and made Charles Darwin one of
the greatest figures in the history of science.
The story of Darwin’s life is a story of long, careful study and
preparation, of rapid publication of his discoveries when he set out
to write them, and finally of triumph over those who opposed him. He
was born on the twelfth of February, 1809, the same day that brought
the world Abraham Lincoln. Someone has said that on that day the
world’s greatest liberators were born--in America the one who would
free the bodies of men from bondage; in England the man who would
free their minds from a no less real slavery to custom, power, and
worn-out dogma.
When he was sixteen years old, Darwin went to Edinburgh to study
medicine. But he was already a rebel against dryness and dead
academic thought, and wrote home that the lectures in anatomy were
quite as dry as was the lecturer himself. After two years of
medicine he gave up his work at Edinburgh, and went to Cambridge to
become a preacher. But while studying for the ministry the young
Darwin spent a great deal of his time with nature, and acquired
something of a reputation as a naturalist. When, in 1831, he was
offered the chance to make a five years’ trip around the world as
naturalist on the exploring ship “Beagle” he did not delay long in
accepting. The things seen, and the facts learned on that long voyage
probably had more to do with making Darwin a great naturalist than
any other single phase of his life. On his return to England the
young man set about writing up the results of his studies while on
his trip, and put into this book most of the arguments which he had
to give in favor of evolution. In 1856 he sent this report to Sir
Joseph Hooker, then the leading authority on plants in England, and
finally in 1859 published his great book, “The Origin of Species.”
This was the first concise statement of a theory of evolution, backed
up by actual evidence, and it created a furore both in Europe and
America. Some scientists eagerly took up with Darwin’s ideas, seeing
in them the explanation of facts that they had long been unable to
understand. Others, lacking in breadth of knowledge, or unwilling
to give up old beliefs, fought bitterly against evolution. The
controversy involved not only scientists, but the churchmen, and was
a leading feature in newspapers, magazines, and books. “The Origin
of Species” ran into many editions, and was translated into several
languages. Darwin found himself a center of interest for the world,
and his theory a cause of heated argument for all who cared to talk
or write about it.
How revolutionary Darwin’s work was, and how unwillingly he himself
came to the conclusion that organic evolution was an undeniable
truth, it is hard for us to understand. For most of us, some at
least, of the essential facts of evolution are every-day knowledge;
we look upon the anti-evolutionist as a strange anachronism--a
hang-over from a past age. But in Darwin’s day conditions were very
different. Thus we find him, in a letter written in 1844 to the great
botanist Hooker, saying:
“I have been ... engaged in a very presumptuous work, and I know
no one individual who would not say a very foolish one. I was so
struck with the distribution of the Galapagos organisms, etc., and
with the character of the American fossil mammifers[14], etc., that
I determined to collect, blindly, every sort of fact, which could
bear in any way on what are species.... At last, gleams of light
have come, and I am almost convinced (quite contrary to the opinion
that I started with) that species are not (it is like confessing
a murder) immutable. Heaven forfend me from Lamarck nonsense[15]
of a ‘tendency to progression,’ ‘adaptations from the slow willing
of animals’, etc.! But the conclusions I am led to are not widely
different from his; though the means of change are wholly so.” This
last statement, as we shall see by reference to the “Origin of
Species” was not wholly true.
Another glimpse at the state of affairs in 1859 and the immediately
succeeding years may be found in Darwin’s anxiety to convince Hooker,
Lyell, and Huxley that species were variable and changeable, and his
rejoicing when Huxley wrote out his very guarded acceptance of the
Darwinian version of organic evolution. We find it hard to conceive
of Huxley, the “warhorse of Darwinism” reluctantly agreeing to most
of Darwin’s points, but at the same time voicing strong objections
to others. And yet these very objections of Huxley’s, made in 1859,
were in 1921 paraded before an audience at one of the country’s
most famous universities as evidence against the truth of organic
evolution!
In France, even more than in England, the “Origin of Species”
was held in disapproval. A translation of the book was offered
to a noted publisher of Paris, and was unceremoniously refused.
The country which had praised Cuvier, and ridiculed Lamarck and
St.-Hilaire was not going to receive willingly the contributions
of an iconoclastic Englishman. We are not surprised to find Darwin
depressed by the European reception of his theories, and writing to
Huxley: “Do you know of any good and speculative foreigners to whom
it would be worth while to send my book?”
But what was this “new” theory of evolution that so aroused the
world? What were its characteristics, and how did if differ from
the theories of Aristotle, Kant, Buffon, and Charles Darwin’s own
grandfather, Dr. Erasmus Darwin?
The theory of evolution set forth in the “Origin of Species”
contained three principal factors: (1) the constant variation of
animals and plants, (2) the struggle for existence, and (3) the
natural selection of those organisms which possess variations which
are of value to them in their attempt to keep alive.
The idea of variation was based upon simple observation. Dr.
Herbert Walter has said that “variation is the most constant thing
in nature,” and paradoxical as that may seem, it is nevertheless
true. No man looks exactly like another man, no tree exactly like
another tree, no shell exactly like another shell. The Japanese
artists appreciate this variation, and make use of their knowledge in
painting, which is one of the reasons why their art is not readily
appreciated by the occidental who is much inclined to “lump” things.
No Japanese artist would think of painting two dogs, or two streams,
or two houses that resembled each other in every respect, for he
knows that every thing in the universe, whether it be alive or dead,
organic or inorganic, differs from every other thing in the universe.
Sometimes the difference is easily seen, as that between a shark
and a goldfish, or a Negro and a Scandinavian or Teuton. At others
it is almost indistinguishable, and can be discovered only by the
most accurate micrometer, or the most precise chemical analysis. But
always the difference exists, the variation is present, and this fact
is the basis for Darwin’s belief in the inborn necessity for all
living things to vary.
The second factor, that of a struggle for existence, was suggested
to Darwin by a reading of Malthus’ classic paper on population.
All creatures normally tend to increase in numbers. Mating fish
produce millions of eggs in a season; chickens rear nestfulls of
young; rabbits and guinea-pigs produce litter after litter of young
from the matings of two parents--everywhere, both in nature and in
domestication, living things seem to be on the increase. And yet
we have no evidence that (excluding the rather doubtful influence
of man) there are more animals on earth today than there were half
a million years ago; the probabilities are that there are fewer.
Clearly, therefore, some process is at work which prevents the
seeming increase from taking place.
In order to understand something of the complexity of this process,
let us select a specific example. Among marine animals, the
oysters are remarkable for the immense numbers of eggs which they
produce--the average for the American oyster is probably about
16,000,000. If all the progeny of a single oyster were to live
and reproduce, and their progeny were to do likewise, and so on
until there were great-great-grandchildren, the total number of
oysters that were descendants of the original pair would be about
66,000,000,000,000,000,000,000,000,000,000,000 and their shells would
make a mass eight times as great as the earth.
Now it is quite obvious that the earth cannot hold, and cover with
water, a mass of oyster shells eight times as great as itself; the
oceans, if they were spread evenly over the surface (which they never
were, and never can be), would accommodate but a few of the great
horde. Neither do those same oceans contain enough food to satisfy,
or begin to satisfy, the needs of these theoretical descendants of a
single oyster. Clearly, therefore, space and food alone are enough to
prevent the undue multiplication of creatures upon the earth.
But there are factors other than space and food which aid in
accomplishing the result. There are water conditions, animal enemies
such as the starfish, and a host of other means by which the
population of oysters is kept down. And even if it were to increase
greatly, the numbers of starfish would at the same time increase,
and simultaneously set about decreasing the numbers of the oysters,
which decrease would in turn cut down the numbers of the starfish,
and so on. Thus we see that the maximum abundance of an organism
is arbitrarily set by the conditions under which that organism
lives. It may attain the limit set for it, but beyond that it may go
only temporarily. Then the surplus dies from starvation, crowding,
animal and plant enemies, and a thousand other of the factors which
constantly work in the constant warfare of nature, the never-ending
“struggle for existence.”
The third factor of Darwinian evolution, that of natural selection,
is based upon the other two. Darwin supposed that the individuals of
a species, or variety, exhibited variations for two reasons: because
it was part of their very nature to do so, and because the conditions
of their environment forced them. In the course of this constant
change there would, of necessity, be some modifications that were
of value to their possessors, while others would appear which were
of more or less definite harm. In the course of the struggle for
existence, those creatures which possessed helpful variations would
naturally possess a certain advantage over those which lacked it or
which exhibited variations which were of harmful nature. Thus in a
cold, snowy climate, that animal which developed a white coat would
be much safer from detection than his companions which might have
fur of a dark hue, either in approaching his prey, or in escaping
his pursuers. The ultimate outcome of this would be that the white
animal would populate the region, while his colored brethren would
soon become extinct. The same principle, Darwin thought, applied to
mental advantages; the more skillful mind triumphed over the less;
the quick-witted animal lived at the expense of the clumsy-witted
one. Throughout the earth, those animals most capable of living
lived, brought forth young, and thus perpetuated their capabilities,
both mental and physical. This process quite plainly helped in the
development of man, and in his progress, but singularly enough,
within his ranks today it does not operate. Great mental capacity is
not today the most important survival factor among humanity. As the
archeologist Keith has pointed out a great philosopher or artist may
lead a life of misery, want, and despair, and leave no descendants,
while a thoughtless, happy Burman will live out his days believing
that the earth is flat and Buddha an all-powerful god, but will leave
behind him a large and rapidly multiplying family.
During the years just prior to the appearance of the “Origin,” Darwin
had an almost complete confidence in the power of natural selection
to account for all the phenomena of evolution. Even in the year
when that work appeared, he wrote Lyell: “Grant a simple archetypal
creature, like the Mud-fish or Lepidosiren, with five senses and some
vestige of mind, and _I believe Natural Selection will account for
the production of every vertebrate animal_.” In publication, however,
he was more cautious, saying, “I am convinced that Natural Selection
has been the main, but not the exclusive means of modification.”
From his extreme position on the effective ability of natural
selection to seize upon a variation and so foster it that a new
species would appear, Darwin slowly but not unwillingly receded.
Ten years after the first publication of the Darwinian theory[16],
he admitted that variations might not have been so supremely
important as he supposed; in 1878 he believed in the direct action
of environment in producing variations, as did Buffon; in 1880
he adopted Lamarck’s theory of the use and disuse of parts. In
1881, in the “Descent of Man,” Darwin lays much stress upon sexual
selection, the idea that members of one sex rendered themselves
particularly attractive in order to capture the attentions of their
would-be mates. This, however, is really a subdivision of the natural
selection idea--in the general reliability of which the famous
evolutionist still believed.
* * * * *
As we have said, in the estimate of Darwin’s general environment,
the world of the middle nineteenth century did not welcome the new
prophet of natural law in the natural world. Many scientists accepted
Darwinism, or at least, the principle of evolution, without reserve;
others made reservations; most of the “intelligentsia” declared it
to be without the slightest element of truth. The public in general,
and especially the church, clung to the old, valueless doctrine of
a multitude of special creations by an omnipotent deity, apparently
forgetting that the greatest of the church fathers, Aquinas and
Augustine, had been prominent evolutionists in their day. There arose
about Darwin’s theories a storm of argument that lasted for many
years, and involved scientists, theologians, philosophers, and laymen
throughout the world.
Darwin, although an excellent and self-confident scientist, was
modest, retiring, and greatly hampered by ill-health contracted
during his “Beagle” voyage. He was forced to leave the work of
publicly defending his theories to other men, the most noted of whom
was Thomas Henry Huxley, the “Bulldog of Evolution.” Huxley was an
accomplished scientist, a powerful speaker, and one of the finest of
European writers of science for the every-day man. He wrote, taught,
and lectured in defense of the evolution theory; after a long,
hard day at the university, he would spend the evening lecturing
before crowds of workingmen from London’s factories, telling them
how one species came from another, and how a single-celled creature
developed into a complex animal with hundreds of millions of cells
in its body, at the same time reconstructing during its growth the
entire evolutionary history of its kind. It was largely because of
the lectures and magazine articles of this tireless scientist, who
believed in the truth of evolution, and enjoyed the task of fighting
for his beliefs, that Darwin achieved so early an almost complete
victory over the scientists who opposed him. Of course, the triumph
was not all-embracing; there are still a few people who follow the
natural sciences and yet refuse to believe that one species can
arise, either by natural selection or by some other means, from
another species without the interference of a deity. And the public
at large, particularly that portion of it which lives far away from
museums, zoological gardens, and centers where illustrated talks on
natural science are regularly given, still believes in the theory
of special creation. But that belief neither signifies defeat for
Darwin and his followers, nor casts doubt upon the essential truth of
their ideas; it simply means that the theory of evolution is still
relatively young, and that popular education is in its infancy.