Comparative anatomy traces the arms and legs of man through various
land forms back to the limbs of fishes. And the human heart and lungs,
the liver, kidneys and stomach, the eyes and ears, the nose and mouth,
have been fashioned from the organs of primitive creatures through
successive modifications during countless ages. The larynx, which makes
possible the human voice, appears in diverse stages of development in
the Amphibia.
Man’s remote ape-like progenitors had tails, and for a time in its
embryonic development, the human babe has a tail longer than his legs
(Fig. 36, middle row). Moreover, in the annals of medical science,
there are records of many otherwise well-formed children born with
tails. Professor Haeckel, in his “Evolution of Man,” shows photographs
of a six-months-old tailed boy (Fig. 37). The presence of this tail is
another rare instance of the vaulting power of heredity—a case in which
Nature recalls a phase of her distant life.
[Illustration: FIG. 37.—TAIL OF A SIX-MONTHS-OLD BOY.
Removed by Operation by Dr. Granville Harrison, in 1901. “A great
number of such cases,” says Haeckel, “are given by Max Bartells in his
essay on ‘Tailed Men,’ 1884.”]
Every human being carries the rudiment of an ancestral tail, the
coccyx, at the base of his spine. In the human embryo, the very muscles
for wagging this tail are still found. In adult man, these muscles
are represented, as a rule, by bands of fibrous tissue. Occasionally,
however, the dissecting surgeon finds these muscles well developed
in the body of a man or woman. Science says that evolution alone can
explain this lingering relic of a tail, with its attendant muscles, in
the human body.
This brings us to another line of evidence, which proves the truth
of evolution—the presence of rudimentary organs. Fig. 38 shows the
vermiform appendix in the orang, in man, and in the babe before birth.
It is much larger in the ape than in man. Man has inherited it from his
ape-like ancestors, and while it serves no purpose in his body, its
infection is the source of the frequently fatal disease, appendicitis.
Then there are the rudimentary muscles of the ear (Fig. 39). In our
remote progenitors these muscles were developed, and with them they
could move their ears. Monkeys move their ears, though not with the
facility characteristic of horses and dogs. Occasionally a man is found
who can move his ears as we move the skin of the forehead. But in the
anthropoid apes and in most men these muscles are inoperative. Through
disuse they have become rudimentary. When the ancestors of these apes
and men began to assume the erect posture, they also began to turn
their heads, instead of their ears, in the direction of sound. As the
erect posture was improved, the turning head answered with increasing
loyalty the call of the sound waves, and after innumerable ages of
comparative rest and disuse, the ear muscles dwindled into their
present impotence. Here, again, evolution alone explains the facts.
[Illustration: FIG. 38.—THE VERMIFORM APPENDIX IN THE ORANG, IN MAN,
AND IN THE HUMAN FOETUS.]
Moreover, the whole external ear is a rudimentary organ—a structure
that has outlived its function. The male breasts point to a time when
the father as well as the mother suckled the young. In some men the
breasts are as well developed as in women and supplied with milk, and
in many known instances babes have been suckled at these male breasts.
Again, in some women and occasionally in men, two or more pairs of
breasts appear—a fact which plainly shows that man has descended
through humbler forms of life. Still another rudimentary organ is the
nictitating membrane—the little fleshy pad at the inner corner of the
eye—the relic of a third eyelid that our ancestors in the dim past
flashed across the eyeball as the turtle and the eagle do to-day.
Man has evolved from creatures that went on all fours and lived in
trees, and in consequence of his upright posture and changed habits
of life, some structures which are active in the apes are rudimentary
in the human body. A shoulder muscle that is a source of strength to
the apes in climbing, lingers in man as a mere fibrous remnant that
has dwindled through disuse. Another muscle which runs through the
wrist into the palm of the hand, another which extends from the calf
of the leg to the sole of the foot, another which passes from the
shoulder to the neck and was once used to lift the collar bone—these
muscles, which are well developed in the true apes, and less developed
in the anthropoids, are rudimentary in man. These rudimentary organs
and muscles are links in the chain of man’s descent and they point
unerringly to the source of his origin.
The long heel and the poorly developed calf of the anthropoid ape
remind us that he has but recently, so to speak, acquired the upright
posture. In the negroid races also the long heel and diminutive calf
are notable characteristics; while in the white and yellow races the
heel is short and the calf well formed and muscular. Once more, the
obvious conclusion is that the black man’s long heel and slender calf
represent a more primitive development; while the leg and heel of the
white man and the Mongolian show the work of evolution farther advanced.
[Illustration: FIG. 39.—THE RUDIMENTARY MUSCLES OF THE EAR.]
Three months before birth, the human babe is covered with a luxuriant
growth of soft, brown hair, called the “lanugo,” precisely the same
as the ape baby. And throughout life the body of every human being
is covered with a rudimentary growth of hair. But this it not all.
It is as suggestive as it is interesting that in man and in the
anthropoid apes the hair on the upper arm and the hair on the lower
arm always grows towards the elbow (Fig. 40)—a phenomenon which occurs
nowhere else in the animal world except in a few American monkeys.
In a primitive Australian race, the Ainos of Japan, and the pygmies
of the Upper Nile, the extreme hairiness of the body is a notable
characteristic. And the photograph of Julia Pastrana, a Siamese (Fig.
41), shows that this lady was not only bearded like a man, but that her
entire body was plentifully clothed with hair. Some chimpanzees, on the
other hand, are remarkably hairless. One variety is, in fact, almost
entirely bald.
If any organ in the human body could distinguish man as a creature
standing apart, and argue that he has not been evolved from ape-like
ancestors, that organ should be the brain. But the brain yields
surprising evidence of man’s kinship with these creatures. Fig. 42
is introduced to show the remarkable similarity in the brains of the
anthropoid apes and men. The lower four are the brains of apes; the
upper one to the right is the brain of a Bushman, and the one at the
upper left is the brain of an European. Mark that while the brains of
the apes differ from one another, there is also a striking difference
between the brain of the savage and that of the civilized man. Observe,
too, how wonderfully these ape brains resemble the human brains, not
alone in general form, but also in the number and depth of their
convolutions. In fact, the brains of man-like apes and men consist of
the same parts—the cerebrum, the cerebellum, the corpus callosum, and
the hippocampus minor—and in both anthropoid and man the cortex of the
brain is folded in essentially the same convolutions.
[Illustration: FIG. 40.—HAIR TRACTS ON ARMS OF MAN AND APE.]
If any thoughtful person is still unconvinced of man’s rise from
ape-like ancestors, let him compare his mental image of some human
beings he has seen with Fig. 43.
Consul II, a chimpanzee from Borneo, now in England, sits at the table,
tucks his napkin under his chin, uses a knife and fork, drinks his tea
from a cup, and has excellent table manners. After dinner, he sits
back, lights his pipe, and enjoys a smoke. He washes himself with soap
and water, dresses himself, shines shoes carefully, and, like a hotel
waiter, expects a tip for his service. Another, and far more remarkable
anthropoid, is Snooky, the educated chimpanzee who frequently appears
in the “movies” in the Chester Comedies. Dressed like a man, this ape
smokes a cigar, pretends to read a paper, poses as a chauffeur, rides a
tricycle, takes care of children, performs capers with boys, and takes
various parts with men and women. So intelligent and humorous is the
acting of this chimpanzee, so clever and human-like are its numerous
performances, that it is justly advertised as the “humanzee.”
[Illustration: FIG. 41.—THE HEAD OF MISS JULIA PASTRANA.
(From a photograph by Hintze).]
In considering the relation between the anthropoid apes and men, we
must not suppose that apes or ape-like creatures underwent a sudden
transformation into human beings. The highest existing apes represent
a development that preceded the appearance of man, some authorities
think, by some two or three million years. The difference between these
creatures and man is therefore the measure of life’s upward rise by
slow steps during that inconceivable time.
Man is related to the apes not alone in the structure of his body and
brain, but also in the blood stream that courses through his veins.
This has been conclusively proved by the remarkable series of blood
tests conducted by Professor G. H. F. Nuttall at Cambridge University.
By these tests, it was shown that man and the chimpanzee are blood
relations; that the gorilla is a more distant relative, and the orang
a relative more distant still. Below the anthropoids, the blood
relationship is represented with diminishing force in the baboons and
monkeys. These blood tests confirm the conclusions of zoology and prove
the truth of evolution.
Fig. 44 is a picture of Haeckel’s genealogical tree of humanity.
It enables us to visualize in its main outline the history of the
evolution of life. At the bottom of the tree are the monera and the
amœbæ—tiny creatures consisting of a single cell. As growing life
assumes diverse forms, the foremost creatures are represented by higher
and higher positions on the trunk of the tree, or by diverging branches
in the ascending order. Life is seen to progress from the simple to the
complex, past the sponges, the molluscs and the fishes, through the
amphibians, the reptiles, the marsupials, rising higher and higher in
the scale of being, through lemurs, apes and anthropoids, until, at the
topmost summit of the tree appears man.
And what has been the secret, the driving force back of this process
of evolution? To understand the causes of evolution, it is necessary
to understand the four fundamental laws of life. First, that while
creatures resemble their parents through heredity, they nevertheless
differ more or less from their parents—this is the law of variation.
Secondly, that more creatures are born than can survive—this is the law
of surplus population. Thirdly, that among living creatures, and owing
largely to over-population, there is continually going on a struggle
for existence—this is the law of struggle. And fourthly, that out of
this struggle there results the survival of the fittest. Variation,
surplus population, struggle, spell the survival of the fittest. In the
struggle for existence, those creatures possessing the best bodies and
the keenest minds, those that could best protect themselves from their
enemies and obtain their food—in a word, those that were best adapted
to their environment—survived, while the others perished. Those whose
variations were unfavorable, the weak, the inferior, died. But those
whose variations were an advantage, the strong, the superior, survived.
In consequence of the survival of the fittest, Nature, throughout the
unfolding ages, kept breeding from the best. And this practice could
have but one result—the gradual improvement of every race of creatures.
It will be well to elucidate somewhat the principles thus summarily
stated. First, then, as to variation. The offspring is never exactly
like its parents, and no two creatures are ever quite alike. The stems,
the leaves, the blossoms of the plants of any species, the size and
contour of their fruits, vary greatly. No two blades of grass, or ears
of corn, or grains of wheat are alike. Every tree has an individuality
of form. The young of dogs, cattle, horses, sheep, of fowls and birds,
invariably differ from their parents in size and form, in coloring and
character.
[Illustration: FIG. 42.—THE BRAINS OF ANTHROPOID APES AND MEN.
G-Gibbon. H-Chimpanzee. I-Orang. K-Gorilla. L-Bushman. M-Teuton. From
Haeckel’s “Evolution of Man.”]
So, too, in a large assemblage of people, you will see noses and ears
of numerous shapes and sizes, eyes displaying a variety of coloration
and expressiveness; you will observe that some foreheads are low
and others high, some heads flat and others pointed, some round and
others square; some men have long arms and legs, some the reverse;
some have long bodies and short limbs, some the opposite; some have
one ear, or shoulder, or hip, higher than the other, or are otherwise
disproportioned. Moreover, great differences may be observed in the
features of almost any family. The black haired mother has red haired
daughters; the father’s features are bequeathed to his sons except,
perhaps, for the eyes of one or the nose of another. Variation is a
basic law of life.
Secondly, as to the multiplication of creatures beyond the power of
Nature to sustain them. Darwin, in the “Origin of Species” says:
“There is no exception to the rule that every organic being naturally
increases at so high a rate, that, if not destroyed, the earth would
soon be covered by the progeny of a single pair. Even slow-breeding
man has doubled in twenty-five years, and at this rate, in less than
a thousand years, there would literally not be standing-room for his
progeny.”
On the fertility of the elephant, Darwin remarks: “The elephant is
reckoned the slowest breeder of all known animals, and I have taken
some pains to estimate its probable minimum rate of natural increase;
it will be safest to assume that it begins breeding when thirty years
old, and goes on breeding till ninety years old, bringing forth six
young in the interval, and surviving till one hundred years old; if
this be true, after a period of from 740 to 750 years there would be
nearly nineteen million elephants alive descended from the first pair.”
An illustration from the opposite extreme of the animal world will
show that the breeding propensities of the largest existing animal are
rivalled by those of the smallest. “The aphis or plant louse,” says Dr.
D. Kerfoot Shute in “A First Book in Organic Evolution,” “is so very
prolific that it has been estimated that the tenth brood of one female
alone would contain more ponderable matter than all the population of
China,—estimating this population at five hundred millions.”
The rabbits introduced into Australia, where they found conditions
ideally favorable to their increase, have multiplied so exceedingly
that they have become a veritable pest. In a brief period, the progeny
of a few rabbits has multiplied into millions, and these creatures
have become so destructive of agriculture that rabbit-killing parties
are organized from time to time and tens of thousands of the animals
are killed with sticks and stones, in open places, the object being to
exterminate as many rabbits as possible in the interest of the farmers’
crops.
In 1850, some enterprising citizens of Brooklyn imported a hundred
English sparrows and gave them to the free city air. A little later,
New York City imported two hundred and twenty of the noisy birds and
liberated them in the parks of the metropolis. Rochester imported one
hundred of the birds, and Philadelphia, with generous public spirit,
opened the bosom of brotherly love to one thousand of the little
strangers whose perpetual chatter formed a striking contrast to the
worshipful quiet dear to the heart of the Quaker City. In the parks,
among the trees, and in the streets of these cities, the sparrows—at
home everywhere—twittered and quarreled in their friendly way, and
multiplied. In twenty-five years the children of these birds had spread
over five hundred square miles. Ten years later they had flung their
domain over fifteen thousand square miles, and men were beginning to
doubt the wisdom of those who had invited them to our shores. Since
then the ubiquitous sparrow has about completed the conquest of the
continent. Darting like an arrow amongst horses’ feet, or dodging
hurrying automobiles, his legions are familiar sights among the traffic
of busy streets. He builds his rude nest under the eaves of houses,
and in the architectural pockets around the roofs of public buildings,
and thrives and multiplies through his wary association with man. The
phenomenal increase in the number of sparrows in North America during a
period of seventy years has been due to the gregarious habit of these
birds and to the favorable character of the environment.
[Illustration: FIG. 43.—JOE AND SALLIE AT HOME.
A Chimpanzee couple of Edward’s Zoological Exhibition. From Dr. Paul
Carus’s “The Rise of Man.” Courtesy of The Open Court Publishing Co.]
Some animals tend to multiply ten fold in a generation; some would
multiply to a hundred fold, and others to ten thousand fold. Not only
could the progeny of any land animal, if given the right of way, soon
crowd the earth, but the fishes, under favorable conditions, would, in
a short time, literally fill the sea. A million eggs are spawned by the
cod-fish in order that two cod-fish may reach maturity. The eel also
spawns millions of ova that a few eels may reach the spawning age. It
is clear, therefore, that if all these eggs produced fishes, and if
these reached maturity and in their turn multiplied with such lavish
prodigality, a few generations would suffice to transform the ocean
into a solid mass.
The same phenomenon obtains in the plant world. Every plant gives its
seeds to the soil as Autumn’s spendthrift hand gives its withered
leaves to the wind, but of the millions of seeds thus scattered,
comparatively few take root and mature and reproduce their kind.
Notwithstanding Nature’s tremendous efforts to overwhelm the earth
with the creatures of every species, the checks upon over-population
are so numerous and so effective that, speaking generally, the number
of animals and plants in any given area where the conditions are
unchanging remains fairly constant. This relatively rigid limitation of
the number of creatures that shall survive in any environment is due to
the operation of Nature’s efficient machinery whose grim function is
the destruction of life.
Millions of creatures live only by devouring other creatures.
The carnivorous animals eat the flesh and drink the blood of the
herbivorous. The larger carnivores feed upon the smaller. That the
badger may make a meal, a whole nest of bees must be destroyed. The
ant-eater swallows a tongue load of ants at a single gulp. The eagle
and the hawk dine on doves and other birds. To the appetite of smaller
birds are sacrificed worms, insects and larvae. Big fishes eat the
little ones; bigger fishes eat the eaters and in turn are eaten. On
land, in the air, and in the sea the incalculable sacrifice of life
proceeds without cessation. Pursuit and flight, capture and death—a
tragedy on which the curtain never falls!
This is the struggle for existence. In this struggle which, in a sense,
is a constant test of skill, the most highly qualified creatures
are the ones best adapted to catch their prey or to escape their
enemies. Differing from their parents and from one another in numerous
variations, some animals excel others in important respects—in having
stronger legs with which to run, better eyes with which to see, a
keener sense of smell, hearing more acute, and teeth and claws better
fitted to hold and rend their prey. To the animal that would obtain
food or avoid being eaten, some or all of these characters are prime
essentials. In the struggle for existence the animals possessing these
attributes in superior form will survive while those in which they are
less developed must perish.
Harmless creatures, no less than harmful, survive through favorable
characters—some by the wit with which they elude the pursuer, some by
flight, some by protective coloration; like the hare whose summer coat
resembles the ground and whose winter garment rivals the whiteness of
the snow, and the gorgeous butterfly, whose folded wings are a perfect
simulation of the form and color of a dead leaf.
Where the herbivorous food was insufficient for the mouths that would
feed upon it, and where animals devoured one another, it was inevitable
that the weak, the stupid, the ill-favored, the incompetent, should
fail in the struggle for existence, and that the strong, the cunning,
the efficient should survive and hand their superior qualities to their
offspring. And this survival of the fittest by right of might that has
been the supreme law of the animal world since life appeared upon this
globe, was bound to result in the accumulation of favorable variations,
in the consequent production of an ever increasing wealth of species,
and in the development of ever higher forms of life.
[Illustration: FIG. 44.—THE GENEALOGICAL TREE OF HUMANITY.]
The fitness of the present forms has been moulded by the death dealing
teeth of the past.
Though not by this means alone. Another potent factor that has wrought
tremendously for evolution has been the changing environment. We may
briefly consider the character of its work. For millions of years
before the close of the Carboniferous period, some ten million years
ago, the whole earth enjoyed a perpetual summer. During the last
million years or more of that vast era, while the dense Carboniferous
forests, overwhelmed again and again by the growing soil, were forming
the coal deposits of the earth, many kinds of amphibians and low
reptiles wandered over the marshes and among the trees.
Then in the succeeding period—the Permian—the climate began to be
colder. For a hundred thousand years or thereby the cold increased. At
last the summit of an ice age was reached, and some four million square
miles of the earth’s surface lay beneath a thick mantle of ice and
snow. That ice sheet covered a continent that then extended from India
to Australia, on the one hand, and to Africa on the other. The ice age,
which was due, probably, to the gradual elevation of the land, wrought
fearful havoc among the land animals, and with a ruthless hand pushed
evolution forward. It compelled animals—and plants also—to change or
die.
In the warm climate that preceded the ice age, all animals were
cold-blooded,—warm blood was not needed—and amphibians and reptiles
left their eggs on the earth to be incubated by the genial air. But in
the awful cold that followed warm blood was required, and, as the cold
destroyed their eggs, it was necessary for animals to develop means of
wooing their young to life within their bodies. Another required change
was that the cold reptile covering be abandoned for a warm coat of hair.
Only a few animals could make these adjustments. Accordingly, as
calculations based upon the fossils prevalent before and after the ice
age have shown, “thirty-nine out of every forty of all the species
of animals and plants on the earth during the coal forest age were
destroyed.” Of the animals that survived, some were saved by migrating
to favorable regions, and some by adapting themselves to the rigors of
the environment. These developed four-chambered hearts to keep their
blood warm; they developed coats of hair or fur to retain the heat
of their bodies; they made such changes in their internal economy as
enabled the young to develop in the body of the mother.
To produce these changes, Nature preserved the favorable variations
that appeared in different animals. From age to age these variations
along advantageous lines were accumulated, and so, in time, the new
creatures were evolved. The result was obtained through natural
selection of the fittest. In this manner arose the mammals, and,
through a variant line of development, the birds; for birds, like
mammals, have four-chambered hearts, and feathers, like hair, are but a
modification of primitive scales; while the bird hatches her eggs with
the warmth of her body. So we may thank that early ice age for the gift
of all mammalian and bird life. The originals of those animals whose
development culminated in man, and of our feathered friends of the air,
were fashioned by that incomparable sculptor—environment.
With the gradual passing of the Permian ice age, through the lowering
of the land, the long backward spring slowly merged into another
universal summer that continued for several million years. In this
mild period, when Europe was, for the most part, a group of scattered
islands, when a continent extended from America to Scotland, a new
garment of multiformed vegetation appeared upon the low-lying earth;
huge sharks and reptiles dominated the sea; while on the land, weird
and prodigious monsters basked in the brilliant sun. It was the age
when the giant reptiles,—some with sail-like wings, and all with
frightful teeth—and ponderous vegetarians held the earth their own and
led in the struggle for existence.
[Illustration: FIG. 45.—TWO PIGS.]
Then came another cold period, less drastic than the former, but severe
enough to give a signal forward urge to the work of evolution. The
great reptiles disappeared forever. And now the primitive birds and
mammals whose evolution had been retarded by their numerous enemies and
by the climate in the warm reptilian age, entered upon a period of more
rapid development. The bracing cold that required movement served as a
stimulant to accelerate their evolution into various forms.
Since that remote time there have been several glacial periods—periods
when great ice caps covered vast areas of the earth—periods whose
tremendous cold was followed by ages when the climate was temperate
and benign. These major changes in the environment, and the numberless
other changes of less striking character, have been among the leading
factors in the work of evolution.
Among the lesser, though important, environmental changes, may
be mentioned the gradual submergence of land beneath the water,
occasioning animal migrations which resulted in the mixing of stocks;
the drying up of swampy regions bringing new plant life; changes in the
food supply transforming animals into vegetarians or carnivores, or
otherwise modifying their habits, and in consequence, their structure.
In these changes that have succeeded one another in the lapse of the
innumerable ages, countless species of animals and plants have been
exterminated altogether; of others, only a few hardy or otherwise
adapted specimens have survived; from these have been bred the animals
and plants of the succeeding ages, which, in turn, have had to adapt
themselves to their environment or disappear; and everywhere the
struggle, whether with the environment or with other living things, has
resulted in the survival of the fittest and the slow improvement of the
fauna and the flora of the world.
The process of selecting the fittest to breed from, as it is carried on
by Nature in her blind way, is called natural selection; and when men,
in breeding stock, select the specimens possessing the most desirable
variations to breed from, the process is named artificial selection.
The great variety of our domestic animals and plants we owe to
artificial selection. Note, for example, the two pigs shown in Fig. 45.
The grizzly one, the wild boar, is the remote ancestor of the other,
the modern, favorite domestic porker. By breeding for many generations
from pigs possessing the most desirable details of form, the legs and
snout of the animal have been shortened, his body has been made more
shapely and greatly enlarged, and his commercial value enormously
increased.
Fig. 46 partially illustrates the diversity of dogs. The dog is a
civilized wolf. And the pugs and poodles, the spaniels and setters,
the hairless dogs and hounds, the terriers and mastiffs, the faithful
collies, the noble St. Bernards, and all the other dogs of every size
and form, have been developed by selecting parents with approved
variations and breeding for desirable results along chosen lines.
In like manner, the barnyard fowls have been developed by selective
breeding. The Leghorns and Minorcas, with their beautiful combs and
wattles, the Golden Spangled and the Silver Spangled Crested Hamburgs,
with their crowning hoods, the noble Plymouth Rocks, with their barred
bodies, the magnificent Light Brahmas and Buff Cochins, arrayed with
wing-like feathery growths to their very toes, the game fowls of the
various varieties—those sleek, trim birds that would rather fight than
eat—and the little Bantams of every sort, proud and beautiful in their
bearing—all these are the children of the rude jungle fowls whose male
birds still shriek a welcome to the morning sun from the wilds of India
and the Malay Islands.
Likewise, the hundred and fifty varieties of our pigeons—the graceful
Modena, the large Runt, the tall Carrier, the Trumpeter with his
strange coo, his hooded head, his winged legs, the Frill-back with his
feathers curling towards his head, the Pouter, with his tall, slender
body, and throat inflated as though a feathered football were pinched
between his beak and breast, the compact Fantail, leaning back with
pride in his beautiful tail that rises above his head like a screen,
the Tumbler, that from a lofty height tumbles with utter abandon
through the air—all these pigeons, whatever their size, their form,
their markings, their habits, have been developed during the last few
centuries from the modest blue rock pigeons of the European coast (Fig.
47).
[Illustration: FIG. 46.—DOGS.
Reading from the top downwards: St. Bernard, Bloodhound, Greyhound,
English Setter, Irish Spaniel, Dalmatian, Pug, Skye Terrier.]
Such is the story that rounds the vast circumference of life. All life
is one, and by the same means its varied ends have been attained. By
breeding from those creatures whose qualifications enabled them to
survive in their environment, Nature, without knowing why, selected the
fittest to become the parents of the creatures that were to follow.
Thus, of necessity, the life of the world, ever branching into an
increasing diversity of species, gradually improved in form, function
and intelligence. And with millions of ages in which to try every
experiment, to test every detail, to destroy her failures and seek
success along other lines, Nature was bound to reach our day with an
array of living creatures of finer development than those that perished
in the struggles of the vanished years.
The laws in accordance with which the humbler creatures have been
developed from still lower forms have presided over the evolution of
man from the beast; and, never pausing in their action, these forces
have slowly fashioned the glories of civilization from the dark crudity
of savage thought. The story of man but continues in another form the
story of life before man appeared.
[Illustration: FIG. 47.—PIGEONS.
Modena 10, Runt 19, Carrier 1, Trumpeter 4, Frill-back 37, Pouter 2,
Fantail 6, Tumbler 15. Rock Doves in Centre.]
The plant creations of Luther Burbank are renowned throughout the
world. The Burbank potato, the Burbank rose, the new walnut trees, the
varieties of plums and prunes, the pineapple quince, the spineless
cactus, the everlasting flower, the beautiful lilies—the many new
species of vegetables, plants, fruits and flowers which Burbank
has created by crossing inferior forms and breeding from the best
resulting specimens—these experimental triumphs in the plant world are
indubitable proofs of the truth of evolution. Mr. Burbank has shown
that plant life is not fixed in form, but plastic and ever-changing,
and that by breeding and selecting in accordance with Nature’s laws,
man can cover the earth with new vegetables, fruits and flowers and
vines and trees and grasses, more luxuriant and more wonderful than any
found in an uncultivated condition.
Life, like clay, is malleable. Slowly, under the urge of Nature,
rapidly in the hands of man, it shapes itself into new moulds. A
problem in mathematics is known to be solved when it can be proved.
In like manner, evolution is known to be certainly true, since, by
following its laws, man now brings into the world new species of
animals and plants that did not exist before.
A wonderful panorama is the story of evolution. From nebula to crusted
earth, to life’s first spark in the primal sea, to the myriad forms
that fought with teeth and claws in forest wilds, to the fierce-browed
creature that earth first knew as human, to the warmth of love and the
glow of thought in the heart and brain of finished man, the forces of
Nature have shaped existence and crowned it with the power of the human
brain. Man the builder, so long the victim of ignorance and fear, may
now shape his destinies in a world fashioned to his choice. The desert
has been made to blossom like the rose; cities of solid masonry have
arisen from the noisome swamp; industries supplying a thousand human
wants now occupy the sites where wild beasts once filled the jungle
with their savage roars; the ocean, earth and air have yielded to the
conquering power of thought; invention, art, discovery, have tapped
exhaustless stores of wealth and culture; literature, the press,
schools, disseminate intelligence; and, rising above earth, man now
solves the secrets of the stars and calculates with precision their
changing movements. Man, Nature’s gifted son, is Nature’s conqueror!
Let him then learn the means by which to further improve his life. Let
him equip his mind with truth. Let him solve his problems in the light
of knowledge and enjoy a rational existence in a well ordered world.