Darwinism (1889) by Alfred Russel Wallace

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[Illustration: FIG. 37.--Chimpanzee (Troglodytes niger).]

_Summary of the Animal Characteristics of Man._

The facts now very briefly summarised amount almost to a demonstration
that man, in his bodily structure, has been derived from the lower
animals, of which he is the culminating development. In his possession
of rudimentary structures which are functional in some of the mammalia;
in the numerous variations of his muscles and other organs agreeing with
characters which are constant in some apes; in his embryonic
development, absolutely identical in character with that of mammalia in
general, and closely resembling in its details that of the higher
quadrumana; in the diseases which he has in common with other mammalia;
and in the wonderful approximation of his skeleton to those of one or
other of the anthropoid apes, we have an amount of evidence in this
direction which it seems impossible to explain away. And this evidence
will appear more forcible if we consider for a moment what the rejection
of it implies. For the only alternative supposition is, that man has
been specially created--that is to say, has been produced in some quite
different way from other animals and altogether independently of them.
But in that case the rudimentary structures, the animal-like variations,
the identical course of development, and all the other animal
characteristics he possesses are deceptive, and inevitably lead us, as
thinking beings making use of the reason which is our noblest and most
distinctive feature, into gross error.

We cannot believe, however, that a careful study of the facts of nature
leads to conclusions directly opposed to the truth; and, as we seek in
vain, in our physical structure and the course of its development, for
any indication of an origin independent of the rest of the animal world,
we are compelled to reject the idea of "special creation" for man, as
being entirely unsupported by facts as well as in the highest degree
improbable.

_The Geological Antiquity of Man._

The evidence we now possess of the exact nature of the resemblance of
man to the various species of anthropoid apes, shows us that he has
little special affinity for any one rather than another species, while
he differs from them all in several important characters in which they
agree with each other. The conclusion to be drawn from these facts is,
that his points of affinity connect him with the whole group, while his
special peculiarities equally separate him from the whole group, and
that he must, therefore, have diverged from the common ancestral form
before the existing types of anthropoid apes had diverged from each
other. Now, this divergence almost certainly took place as early as the
Miocene period, because in the Upper Miocene deposits of Western Europe
remains of two species of ape have been found allied to the gibbons, one
of them, Dryopithecus, nearly as large as a man, and believed by M.
Lartet to have approached man in its dentition more than the existing
apes. We seem hardly, therefore, to have reached, in the Upper Miocene,
the epoch of the common ancestor of man and the anthropoids.

The evidence of the antiquity of man himself is also scanty, and takes
us but very little way back into the past. We have clear proof of his
existence in Europe in the latter stages of the glacial epoch, with many
indications of his presence in interglacial or even pre-glacial times;
while both the actual remains and the works of man found in the
auriferous gravels of California deep under lava-flows of Pliocene age,
show that he existed in the New World at least as early as in the
Old.[224] These earliest remains of man have been received with doubt,
and even with ridicule, as if there were some extreme improbability in
them. But, in point of fact, the wonder is that human remains have not
been found more frequently in pre-glacial deposits. Referring to the
most ancient fossil remains found in Europe--the Engis and Neanderthal
crania,--Professor Huxley makes the following weighty remark: "In
conclusion, I may say, that the fossil remains of Man hitherto
discovered do not seem to me to take us appreciably nearer to that lower
pithecoid form, by the modification of which he has, probably, become
what he is." The Californian remains and works of art, above referred
to, give no indication of a specially low form of man; and it remains an
unsolved problem why no traces of the long line of man's ancestors, back
to the remote period when he first branched off from the pithecoid type,
have yet been discovered.

It has been objected by some writers--notably by Professor Boyd
Dawkins--that man did not probably exist in Pliocene times, because
almost all the known mammalia of that epoch are distinct species from
those now living on the earth, and that the same changes of the
environment which led to the modification of other mammalian species
would also have led to a change in man. But this argument overlooks the
fact that man differs essentially from all other mammals in this
respect, that whereas any important adaptation to new conditions can be
effected in them only by a change in bodily structure, man is able to
adapt himself to much greater changes of conditions by a mental
development leading him to the use of fire, of tools, of clothing, of
improved dwellings, of nets and snares, and of agriculture. By the help
of these, without any change whatever in his bodily structure, he has
been able to spread over and occupy the whole earth; to dwell securely
in forest, plain, or mountain; to inhabit alike the burning desert or
the arctic wastes; to cope with every kind of wild beast, and to provide
himself with food in districts where, as an animal trusting to nature's
unaided productions, he would have starved.[225]

It follows, therefore, that from the time when the ancestral man first
walked erect, with hands freed from any active part in locomotion, and
when his brain-power became sufficient to cause him to use his hands in
making weapons and tools, houses and clothing, to use fire for cooking,
and to plant seeds or roots to supply himself with stores of food, the
power of natural selection would cease to act in producing modifications
of his body, but would continuously advance his mind through the
development of its organ, the brain. Hence man may have become truly
man--the species, Homo sapiens--even in the Miocene period; and while
all other mammals were becoming modified from age to age under the
influence of ever-changing physical and biological conditions, he would
be advancing mainly in intelligence, but perhaps also in stature, and by
that advance alone would be able to maintain himself as the master of
all other animals and as the most widespread occupier of the earth. It
is quite in accordance with this view that we find the most pronounced
distinction between man and the anthropoid apes in the size and
complexity of his brain. Thus, Professor Huxley tells us that "it may be
doubted whether a healthy human adult brain ever weighed less than 31
or 32 ounces, or that the heaviest gorilla brain has exceeded 20
ounces," although "a full-grown gorilla is probably pretty nearly twice
as heavy as a Bosjes man, or as many an European woman."[226] The
average human brain, however, weighs 48 or 49 ounces, and if we take the
average ape brain at only 2 ounces less than the very largest gorilla's
brain, or 18 ounces, we shall see better the enormous increase which has
taken place in the brain of man since the time when he branched off from
the apes; and this increase will be still greater if we consider that
the brains of apes, like those of all other mammals, have also increased
from earlier to later geological times.

If these various considerations are taken into account, we must conclude
that the essential features of man's structure as compared with that of
apes--his erect posture and free hands--were acquired at a comparatively
early period, and were, in fact, the characteristics which gave him his
superiority over other mammals, and started him on the line of
development which has led to his conquest of the world. But during this
long and steady development of brain and intellect, mankind must have
continuously increased in numbers and in the area which they
occupied--they must have formed what Darwin terms a "dominant race." For
had they been few in numbers and confined to a limited area, they could
hardly have successfully struggled against the numerous fierce carnivora
of that period, and against those adverse influences which led to the
extinction of so many more powerful animals. A large population spread
over an extensive area is also needed to supply an adequate number of
brain variations for man's progressive improvement. But this large
population and long-continued development in a single line of advance
renders it the more difficult to account for the complete absence of
human or pre-human remains in all those deposits which have furnished,
in such rich abundance, the remains of other land animals. It is true
that the remains of apes are also very rare, and we may well suppose
that the superior intelligence of man led him to avoid that extensive
destruction by flood or in morass which seems to have often overwhelmed
other animals. Yet, when we consider that, even in our own day, men are
not unfrequently overwhelmed by volcanic eruptions, as in Java and
Japan, or carried away in vast numbers by floods, as in Bengal and
China, it seems impossible but that ample remains of Miocene and
Pliocene man do exist buried in the most recent layers of the earth's
crust, and that more extended research or some fortunate discovery will
some day bring them to light.

_The Probable Birthplace of Man._

It has usually been considered that the ancestral form of man originated
in the tropics, where vegetation is most abundant and the climate most
equable. But there are some important objections to this view. The
anthropoid apes, as well as most of the monkey tribe, are essentially
arboreal in their structure, whereas the great distinctive character of
man is his special adaptation to terrestrial locomotion. We can hardly
suppose, therefore, that he originated in a forest region, where fruits
to be obtained by climbing are the chief vegetable food. It is more
probable that he began his existence on the open plains or high plateaux
of the temperate or sub-tropical zone, where the seeds of indigenous
cereals and numerous herbivora, rodents, and game-birds, with fishes and
molluscs in the lakes, rivers, and seas supplied him with an abundance
of varied food. In such a region he would develop skill as a hunter,
trapper, or fisherman, and later as a herdsman and cultivator,--a
succession of which we find indications in the palaeolithic and
neolithic races of Europe.

In seeking to determine the particular areas in which his earliest
traces are likely to be found, we are restricted to some portion of the
Eastern hemisphere, where alone the anthropoid apes exist, or have
apparently ever existed.

There is good reason to believe, also, that Africa must be excluded,
because it is known to have been separated from the northern continent
in early tertiary times, and to have acquired its existing fauna of the
higher mammalia by a later union with that continent after the
separation from it of Madagascar, an island which has preserved for us a
sample, as it were, of the early African mammalian fauna, from which not
only the anthropoid apes, but all the higher quadrumana are
absent.[227] There remains only the great Euro-Asiatic continent; and
its enormous plateaux, extending from Persia right across Tibet and
Siberia to Manchuria, afford an area, some part or other of which
probably offered suitable conditions, in late Miocene or early Pliocene
times, for the development of ancestral man.

It is in this area that we still find that type of mankind--the
Mongolian--which retains a colour of the skin midway between the black
or brown-black of the negro, and the ruddy or olive-white of the
Caucasian types, a colour which still prevails over all Northern Asia,
over the American continents, and over much of Polynesia. From this
primary tint arose, under the influence of varied conditions, and
probably in correlation with constitutional changes adapted to peculiar
climates, the varied tints which still exist among mankind. If the
reasoning by which this conclusion is reached be sound, and all the
earlier stages of man's development from an animal form occurred in the
area now indicated, we can better understand how it is that we have as
yet met with no traces of the missing links, or even of man's existence
during late tertiary times, because no part of the world is so entirely
unexplored by the geologist as this very region. The area in question is
sufficiently extensive and varied to admit of primeval man having
attained to a considerable population, and having developed his full
human characteristics, both physical and mental, before there was any
need for him to migrate beyond its limits. One of his earliest important
migrations was probably into Africa, where, spreading westward, he
became modified in colour and hair in correlation with physiological
changes adapting him to the climate of the equatorial lowlands.
Spreading north-westward into Europe the moist and cool climate led to a
modification of an opposite character, and thus may have arisen the
three great human types which still exist. Somewhat later, probably, he
spread eastward into North-West America and soon scattered himself over
the whole continent; and all this may well have occurred in early or
middle Pliocene times. Thereafter, at very long intervals, successive
waves of migration carried him into every part of the habitable world,
and by conquest and intermixture led ultimately to that puzzling
gradation of types which the ethnologist in vain seeks to unravel.

_The Origin of the Moral and Intellectual Nature of Man._

From the foregoing discussion it will be seen that I fully accept Mr.
Darwin's conclusion as to the essential identity of man's bodily
structure with that of the higher mammalia, and his descent from some
ancestral form common to man and the anthropoid apes. The evidence of
such descent appears to me to be overwhelming and conclusive. Again, as
to the cause and method of such descent and modification, we may admit,
at all events provisionally, that the laws of variation and natural
selection, acting through the struggle for existence and the continual
need of more perfect adaptation to the physical and biological
environments, may have brought about, first that perfection of bodily
structure in which he is so far above all other animals, and in
co-ordination with it the larger and more developed brain, by means of
which he has been able to utilise that structure in the more and more
complete subjection of the whole animal and vegetable kingdoms to his
service.

But this is only the beginning of Mr. Darwin's work, since he goes on to
discuss the moral nature and mental faculties of man, and derives these
too by gradual modification and development from the lower animals.
Although, perhaps, nowhere distinctly formulated, his whole argument
tends to the conclusion that man's entire nature and all his faculties,
whether moral, intellectual, or spiritual, have been derived from their
rudiments in the lower animals, in the same manner and by the action of
the same general laws as his physical structure has been derived. As
this conclusion appears to me not to be supported by adequate evidence,
and to be directly opposed to many well-ascertained facts, I propose to
devote a brief space to its discussion.

_The Argument from Continuity._

Mr. Darwin's mode of argument consists in showing that the rudiments of
most, if not of all, the mental and moral faculties of man can be
detected in some animals. The manifestations of intelligence, amounting
in some cases to distinct acts of reasoning, in many animals, are
adduced as exhibiting in a much less degree the intelligence and reason
of man. Instances of curiosity, imitation, attention, wonder, and memory
are given; while examples are also adduced which may be interpreted as
proving that animals exhibit kindness to their fellows, or manifest
pride, contempt, and shame. Some are said to have the rudiments of
language, because they utter several different sounds, each of which has
a definite meaning to their fellows or to their young; others the
rudiments of arithmetic, because they seem to count and remember up to
three, four, or even five. A sense of beauty is imputed to them on
account of their own bright colours or the use of coloured objects in
their nests; while dogs, cats, and horses are said to have imagination,
because they appear to be disturbed by dreams. Even some distant
approach to the rudiments of religion is said to be found in the deep
love and complete submission of a dog to his master.[228]

Turning from animals to man, it is shown that in the lowest savages many
of these faculties are very little advanced from the condition in which
they appear in the higher animals; while others, although fairly well
exhibited, are yet greatly inferior to the point of development they
have reached in civilised races. In particular, the moral sense is said
to have been developed from the social instincts of savages, and to
depend mainly on the enduring discomfort produced by any action which
excites the general disapproval of the tribe. Thus, every act of an
individual which is believed to be contrary to the interests of the
tribe, excites its unvarying disapprobation and is held to be immoral;
while every act, on the other hand, which is, as a rule, beneficial to
the tribe, is warmly and constantly approved, and is thus considered to
be right or moral. From the mental struggle, when an act that would
benefit self is injurious to the tribe, there arises conscience; and
thus the social instincts are the foundation of the moral sense and of
the fundamental principles of morality.[229]

The question of the origin and nature of the moral sense and of
conscience is far too vast and complex to be discussed here, and a
reference to it has been introduced only to complete the sketch of Mr.
Darwin's view of the continuity and gradual development of all human
faculties from the lower animals up to savages, and from savage up to
civilised man. The point to which I wish specially to call attention is,
that to prove continuity and the progressive development of the
intellectual and moral faculties from animals to man, is not the same as
proving that these faculties have been developed by natural selection;
and this last is what Mr. Darwin has hardly attempted, although to
support his theory it was absolutely essential to prove it. Because
man's physical structure has been developed from an animal form by
natural selection, it does not necessarily follow that his mental
nature, even though developed _pari passu_ with it, has been developed
by the same causes only. To illustrate by a physical analogy. Upheaval
and depression of land, combined with sub-aerial denudation by wind and
frost, rain and rivers, and marine denudation on coastlines, were long
thought to account for all the modelling of the earth's surface not
directly due to volcanic action; and in the early editions of Lyell's
_Principles of Geology_ these are the sole causes appealed to. But when
the action of glaciers was studied and the recent occurrence of a
glacial epoch demonstrated as a fact, many phenomena--such as moraines
and other gravel deposits, boulder clay, erratic boulders, grooved and
rounded rocks, and Alpine lake basins--were seen to be due to this
altogether distinct cause. There was no breach of continuity, no sudden
catastrophe; the cold period came on and passed away in the most gradual
manner, and its effects often passed insensibly into those produced by
denudation or upheaval; yet none the less a new agency appeared at a
definite time, and new effects were produced which, though continuous
with preceding effects, were not due to the same causes. It is not,
therefore, to be assumed, without proof or against independent evidence,
that the later stages of an apparently continuous development are
necessarily due to the same causes only as the earlier stages. Applying
this argument to the case of man's intellectual and moral nature, I
propose to show that certain definite portions of it could not have been
developed by variation and natural selection alone, and that, therefore,
some other influence, law, or agency is required to account for them.
If this can be clearly shown for any one or more of the special
faculties of intellectual man, we shall be justified in assuming that
the same unknown cause or power may have had a much wider influence, and
may have profoundly influenced the whole course of his development.

_The Origin of the Mathematical Faculty._

We have ample evidence that, in all the lower races of man, what may be
termed the mathematical faculty is, either absent, or, if present, quite
unexercised. The Bushmen and the Brazilian Wood-Indians are said not to
count beyond two. Many Australian tribes only have words for one and
two, which are combined to make three, four, five, or six, beyond which
they do not count. The Damaras of South Africa only count to three; and
Mr. Galton gives a curious description of how one of them was hopelessly
puzzled when he had sold two sheep for two sticks of tobacco each, and
received four sticks in payment. He could only find out that he was
correctly paid by taking two sticks and then giving one sheep, then
receiving two sticks more and giving the other sheep. Even the
comparatively intellectual Zulus can only count up to ten by using the
hands and fingers. The Ahts of North-West America count in nearly the
same manner, and most of the tribes of South America are no further
advanced.[230] The Kaffirs have great herds of cattle, and if one is
lost they miss it immediately, but this is not by counting, but by
noticing the absence of one they know; just as in a large family or a
school a boy is missed without going through the process of counting.
Somewhat higher races, as the Esquimaux, can count up to twenty by using
the hands and the feet; and other races get even further than this by
saying "one man" for twenty, "two men" for forty, and so on, equivalent
to our rural mode of reckoning by scores. From the fact that so many of
the existing savage races can only count to four or five, Sir John
Lubbock thinks it improbable that our earliest ancestors could have
counted as high as ten.[231]

When we turn to the more civilised races, we find the use of numbers
and the art of counting greatly extended. Even the Tongas of the South
Sea islands are said to have been able to count as high as 100,000. But
mere counting does not imply either the possession or the use of
anything that can be really called the mathematical faculty, the
exercise of which in any broad sense has only been possible since the
introduction of the decimal notation. The Greeks, the Romans, the
Egyptians, the Jews, and the Chinese had all such cumbrous systems, that
anything like a science of arithmetic, beyond very simple operations,
was impossible; and the Roman system, by which the year 1888 would be
written MDCCCLXXXVIII, was that in common use in Europe down to the
fourteenth or fifteenth centuries, and even much later in some places.
Algebra, which was invented by the Hindoos, from whom also came the
decimal notation, was not introduced into Europe till the thirteenth
century, although the Greeks had some acquaintance with it; and it
reached Western Europe from Italy only in the sixteenth century.[232] It
was, no doubt, owing to the absence of a sound system of numeration that
the mathematical talent of the Greeks was directed chiefly to geometry,
in which science Euclid, Archimedes, and others made such brilliant
discoveries. It is, however, during the last three centuries only that
the civilised world appears to have become conscious of the possession
of a marvellous faculty which, when supplied with the necessary tools in
the decimal notation, the elements of algebra and geometry, and the
power of rapidly communicating discoveries and ideas by the art of
printing, has developed to an extent, the full grandeur of which can be
appreciated only by those who have devoted some time (even if
unsuccessfully) to the study.

The facts now set forth as to the almost total absence of mathematical
faculty in savages and its wonderful development in quite recent times,
are exceedingly suggestive, and in regard to them we are limited to two
possible theories. Either prehistoric and savage man did not possess
this faculty at all (or only in its merest rudiments); or they did
possess it, but had neither the means nor the incitements for its
exercise. In the former case we have to ask by what means has this
faculty been so rapidly developed in all civilised races, many of which
a few centuries back were, in this respect, almost savages themselves;
while in the latter case the difficulty is still greater, for we have to
assume the existence of a faculty which had never been used either by
the supposed possessors of it or by their ancestors.