their fur, and the ornamental tufts about the head, have all been acquired
through sexual selection. As the order of development during growth,
generally indicates the order in which the characters of a species have
been developed and modified during previous generations; and as the newly-
born infants of the various races of man do not differ nearly as much in
colour as do the adults, although their bodies are as completely destitute
of hair, we have some slight evidence that the tints of the different races
were acquired at a period subsequent to the removal of the hair, which must
have occurred at a very early period in the history of man.
SUMMARY.
We may conclude that the greater size, strength, courage, pugnacity, and
energy of man, in comparison with woman, were acquired during primeval
times, and have subsequently been augmented, chiefly through the contests
of rival males for the possession of the females. The greater intellectual
vigour and power of invention in man is probably due to natural selection,
combined with the inherited effects of habit, for the most able men will
have succeeded best in defending and providing for themselves and for their
wives and offspring. As far as the extreme intricacy of the subject
permits us to judge, it appears that our male ape-like progenitors acquired
their beards as an ornament to charm or excite the opposite sex, and
transmitted them only to their male offspring. The females apparently
first had their bodies denuded of hair, also as a sexual ornament; but they
transmitted this character almost equally to both sexes. It is not
improbable that the females were modified in other respects for the same
purpose and by the same means; so that women have acquired sweeter voices
and become more beautiful than men.
It deserves attention that with mankind the conditions were in many
respects much more favourable for sexual selection, during a very early
period, when man had only just attained to the rank of manhood, than during
later times. For he would then, as we may safely conclude, have been
guided more by his instinctive passions, and less by foresight or reason.
He would have jealously guarded his wife or wives. He would not have
practised infanticide; nor valued his wives merely as useful slaves; nor
have been betrothed to them during infancy. Hence we may infer that the
races of men were differentiated, as far as sexual selection is concerned,
in chief part at a very remote epoch; and this conclusion throws light on
the remarkable fact that at the most ancient period, of which we have not
as yet any record, the races of man had already come to differ nearly or
quite as much as they do at the present day.
The views here advanced, on the part which sexual selection has played in
the history of man, want scientific precision. He who does not admit this
agency in the case of the lower animals, will disregard all that I have
written in the later chapters on man. We cannot positively say that this
character, but not that, has been thus modified; it has, however, been
shewn that the races of man differ from each other and from their nearest
allies, in certain characters which are of no service to them in their
daily habits of life, and which it is extremely probable would have been
modified through sexual selection. We have seen that with the lowest
savages the people of each tribe admire their own characteristic
qualities, - the shape of the head and face, the squareness of the cheek-
bones, the prominence or depression of the nose, the colour of the skin,
the length of the hair on the head, the absence of hair on the face and
body, or the presence of a great beard, and so forth. Hence these and
other such points could hardly fail to be slowly and gradually exaggerated,
from the more powerful and able men in each tribe, who would succeed in
rearing the largest number of offspring, having selected during many
generations for their wives the most strongly characterised and therefore
most attractive women. For my own part I conclude that of all the causes
which have led to the differences in external appearance between the races
of man, and to a certain extent between man and the lower animals, sexual
selection has been the most efficient.
CHAPTER XXI.
GENERAL SUMMARY AND CONCLUSION.
Main conclusion that man is descended from some lower form - Manner of
development - Genealogy of man - Intellectual and moral faculties - Sexual
Selection - Concluding remarks.
A brief summary will be sufficient to recall to the reader's mind the more
salient points in this work. Many of the views which have been advanced
are highly speculative, and some no doubt will prove erroneous; but I have
in every case given the reasons which have led me to one view rather than
to another. It seemed worth while to try how far the principle of
evolution would throw light on some of the more complex problems in the
natural history of man. False facts are highly injurious to the progress
of science, for they often endure long; but false views, if supported by
some evidence, do little harm, for every one takes a salutary pleasure in
proving their falseness: and when this is done, one path towards error is
closed and the road to truth is often at the same time opened.
The main conclusion here arrived at, and now held by many naturalists who
are well competent to form a sound judgment, is that man is descended from
some less highly organised form. The grounds upon which this conclusion
rests will never be shaken, for the close similarity between man and the
lower animals in embryonic development, as well as in innumerable points of
structure and constitution, both of high and of the most trifling
importance, - the rudiments which he retains, and the abnormal reversions to
which he is occasionally liable, - are facts which cannot be disputed. They
have long been known, but until recently they told us nothing with respect
to the origin of man. Now when viewed by the light of our knowledge of the
whole organic world, their meaning is unmistakable. The great principle of
evolution stands up clear and firm, when these groups or facts are
considered in connection with others, such as the mutual affinities of the
members of the same group, their geographical distribution in past and
present times, and their geological succession. It is incredible that all
these facts should speak falsely. He who is not content to look, like a
savage, at the phenomena of nature as disconnected, cannot any longer
believe that man is the work of a separate act of creation. He will be
forced to admit that the close resemblance of the embryo of man to that,
for instance, of a dog - the construction of his skull, limbs and whole
frame on the same plan with that of other mammals, independently of the
uses to which the parts may be put - the occasional re-appearance of various
structures, for instance of several muscles, which man does not normally
possess, but which are common to the Quadrumana - and a crowd of analogous
facts - all point in the plainest manner to the conclusion that man is the
co-descendant with other mammals of a common progenitor.
We have seen that man incessantly presents individual differences in all
parts of his body and in his mental faculties. These differences or
variations seem to be induced by the same general causes, and to obey the
same laws as with the lower animals. In both cases similar laws of
inheritance prevail. Man tends to increase at a greater rate than his
means of subsistence; consequently he is occasionally subjected to a severe
struggle for existence, and natural selection will have effected whatever
lies within its scope. A succession of strongly-marked variations of a
similar nature is by no means requisite; slight fluctuating differences in
the individual suffice for the work of natural selection; not that we have
any reason to suppose that in the same species, all parts of the
organisation tend to vary to the same degree. We may feel assured that the
inherited effects of the long-continued use or disuse of parts will have
done much in the same direction with natural selection. Modifications
formerly of importance, though no longer of any special use, are long-
inherited. When one part is modified, other parts change through the
principle of correlation, of which we have instances in many curious cases
of correlated monstrosities. Something may be attributed to the direct and
definite action of the surrounding conditions of life, such as abundant
food, heat or moisture; and lastly, many characters of slight physiological
importance, some indeed of considerable importance, have been gained
through sexual selection.
No doubt man, as well as every other animal, presents structures, which
seem to our limited knowledge, not to be now of any service to him, nor to
have been so formerly, either for the general conditions of life, or in the
relations of one sex to the other. Such structures cannot be accounted for
by any form of selection, or by the inherited effects of the use and disuse
of parts. We know, however, that many strange and strongly-marked
peculiarities of structure occasionally appear in our domesticated
productions, and if their unknown causes were to act more uniformly, they
would probably become common to all the individuals of the species. We may
hope hereafter to understand something about the causes of such occasional
modifications, especially through the study of monstrosities: hence the
labours of experimentalists, such as those of M. Camille Dareste, are full
of promise for the future. In general we can only say that the cause of
each slight variation and of each monstrosity lies much more in the
constitution of the organism, than in the nature of the surrounding
conditions; though new and changed conditions certainly play an important
part in exciting organic changes of many kinds.
Through the means just specified, aided perhaps by others as yet
undiscovered, man has been raised to his present state. But since he
attained to the rank of manhood, he has diverged into distinct races, or as
they may be more fitly called, sub-species. Some of these, such as the
Negro and European, are so distinct that, if specimens had been brought to
a naturalist without any further information, they would undoubtedly have
been considered by him as good and true species. Nevertheless all the
races agree in so many unimportant details of structure and in so many
mental peculiarities that these can be accounted for only by inheritance
from a common progenitor; and a progenitor thus characterised would
probably deserve to rank as man.
It must not be supposed that the divergence of each race from the other
races, and of all from a common stock, can be traced back to any one pair
of progenitors. On the contrary, at every stage in the process of
modification, all the individuals which were in any way better fitted for
their conditions of life, though in different degrees, would have survived
in greater numbers than the less well-fitted. The process would have been
like that followed by man, when he does not intentionally select particular
individuals, but breeds from all the superior individuals, and neglects the
inferior. He thus slowly but surely modifies his stock, and unconsciously
forms a new strain. So with respect to modifications acquired
independently of selection, and due to variations arising from the nature
of the organism and the action of the surrounding conditions, or from
changed habits of life, no single pair will have been modified much more
than the other pairs inhabiting the same country, for all will have been
continually blended through free intercrossing.
By considering the embryological structure of man, - the homologies which he
presents with the lower animals, - the rudiments which he retains, - and the
reversions to which he is liable, we can partly recall in imagination the
former condition of our early progenitors; and can approximately place them
in their proper place in the zoological series. We thus learn that man is
descended from a hairy, tailed quadruped, probably arboreal in its habits,
and an inhabitant of the Old World. This creature, if its whole structure
had been examined by a naturalist, would have been classed amongst the
Quadrumana, as surely as the still more ancient progenitor of the Old and
New World monkeys. The Quadrumana and all the higher mammals are probably
derived from an ancient marsupial animal, and this through a long line of
diversified forms, from some amphibian-like creature, and this again from
some fish-like animal. In the dim obscurity of the past we can see that
the early progenitor of all the Vertebrata must have been an aquatic
animal, provided with branchiae, with the two sexes united in the same
individual, and with the most important organs of the body (such as the
brain and heart) imperfectly or not at all developed. This animal seems to
have been more like the larvae of the existing marine Ascidians than any
other known form.
The high standard of our intellectual powers and moral disposition is the
greatest difficulty which presents itself, after we have been driven to
this conclusion on the origin of man. But every one who admits the
principle of evolution, must see that the mental powers of the higher
animals, which are the same in kind with those of man, though so different
in degree, are capable of advancement. Thus the interval between the
mental powers of one of the higher apes and of a fish, or between those of
an ant and scale-insect, is immense; yet their development does not offer
any special difficulty; for with our domesticated animals, the mental
faculties are certainly variable, and the variations are inherited. No one
doubts that they are of the utmost importance to animals in a state of
nature. Therefore the conditions are favourable for their development
through natural selection. The same conclusion may be extended to man; the
intellect must have been all-important to him, even at a very remote
period, as enabling him to invent and use language, to make weapons, tools,
traps, etc., whereby with the aid of his social habits, he long ago became
the most dominant of all living creatures.
A great stride in the development of the intellect will have followed, as
soon as the half-art and half-instinct of language came into use; for the
continued use of language will have reacted on the brain and produced an
inherited effect; and this again will have reacted on the improvement of
language. As Mr. Chauncey Wright (1. 'On the Limits of Natural
Selection,' in the 'North American Review,' Oct. 1870, p. 295.) has well
remarked, the largeness of the brain in man relatively to his body,
compared with the lower animals, may be attributed in chief part to the
early use of some simple form of language, - that wonderful engine which
affixes signs to all sorts of objects and qualities, and excites trains of
thought which would never arise from the mere impression of the senses, or
if they did arise could not be followed out. The higher intellectual
powers of man, such as those of ratiocination, abstraction, self-
consciousness, etc., probably follow from the continued improvement and
exercise of the other mental faculties.
The development of the moral qualities is a more interesting problem. The
foundation lies in the social instincts, including under this term the
family ties. These instincts are highly complex, and in the case of the
lower animals give special tendencies towards certain definite actions; but
the more important elements are love, and the distinct emotion of sympathy.
Animals endowed with the social instincts take pleasure in one another's
company, warn one another of danger, defend and aid one another in many
ways. These instincts do not extend to all the individuals of the species,
but only to those of the same community. As they are highly beneficial to
the species, they have in all probability been acquired through natural
selection.
A moral being is one who is capable of reflecting on his past actions and
their motives - of approving of some and disapproving of others; and the
fact that man is the one being who certainly deserves this designation, is
the greatest of all distinctions between him and the lower animals. But in
the fourth chapter I have endeavoured to shew that the moral sense follows,
firstly, from the enduring and ever-present nature of the social instincts;
secondly, from man's appreciation of the approbation and disapprobation of
his fellows; and thirdly, from the high activity of his mental faculties,
with past impressions extremely vivid; and in these latter respects he
differs from the lower animals. Owing to this condition of mind, man
cannot avoid looking both backwards and forwards, and comparing past
impressions. Hence after some temporary desire or passion has mastered his
social instincts, he reflects and compares the now weakened impression of
such past impulses with the ever-present social instincts; and he then
feels that sense of dissatisfaction which all unsatisfied instincts leave
behind them, he therefore resolves to act differently for the future, - and
this is conscience. Any instinct, permanently stronger or more enduring
than another, gives rise to a feeling which we express by saying that it
ought to be obeyed. A pointer dog, if able to reflect on his past conduct,
would say to himself, I ought (as indeed we say of him) to have pointed at
that hare and not have yielded to the passing temptation of hunting it.
Social animals are impelled partly by a wish to aid the members of their
community in a general manner, but more commonly to perform certain
definite actions. Man is impelled by the same general wish to aid his
fellows; but has few or no special instincts. He differs also from the
lower animals in the power of expressing his desires by words, which thus
become a guide to the aid required and bestowed. The motive to give aid is
likewise much modified in man: it no longer consists solely of a blind
instinctive impulse, but is much influenced by the praise or blame of his
fellows. The appreciation and the bestowal of praise and blame both rest
on sympathy; and this emotion, as we have seen, is one of the most
important elements of the social instincts. Sympathy, though gained as an
instinct, is also much strengthened by exercise or habit. As all men
desire their own happiness, praise or blame is bestowed on actions and
motives, according as they lead to this end; and as happiness is an
essential part of the general good, the greatest-happinesss principle
indirectly serves as a nearly safe standard of right and wrong. As the
reasoning powers advance and experience is gained, the remoter effects of
certain lines of conduct on the character of the individual, and on the
general good, are perceived; and then the self-regarding virtues come
within the scope of public opinion, and receive praise, and their opposites
blame. But with the less civilised nations reason often errs, and many bad
customs and base superstitions come within the same scope, and are then
esteemed as high virtues, and their breach as heavy crimes.
The moral faculties are generally and justly esteemed as of higher value
than the intellectual powers. But we should bear in mind that the activity
of the mind in vividly recalling past impressions is one of the fundamental
though secondary bases of conscience. This affords the strongest argument
for educating and stimulating in all possible ways the intellectual
faculties of every human being. No doubt a man with a torpid mind, if his
social affections and sympathies are well developed, will be led to good
actions, and may have a fairly sensitive conscience. But whatever renders
the imagination more vivid and strengthens the habit of recalling and
comparing past impressions, will make the conscience more sensitive, and
may even somewhat compensate for weak social affections and sympathies.
The moral nature of man has reached its present standard, partly through
the advancement of his reasoning powers and consequently of a just public
opinion, but especially from his sympathies having been rendered more
tender and widely diffused through the effects of habit, example,
instruction, and reflection. It is not improbable that after long practice
virtuous tendencies may be inherited. With the more civilised races, the
conviction of the existence of an all-seeing Deity has had a potent
influence on the advance of morality. Ultimately man does not accept the
praise or blame of his fellows as his sole guide, though few escape this
influence, but his habitual convictions, controlled by reason, afford him
the safest rule. His conscience then becomes the supreme judge and
monitor. Nevertheless the first foundation or origin of the moral sense
lies in the social instincts, including sympathy; and these instincts no
doubt were primarily gained, as in the case of the lower animals, through
natural selection.
The belief in God has often been advanced as not only the greatest, but the
most complete of all the distinctions between man and the lower animals.
It is however impossible, as we have seen, to maintain that this belief is
innate or instinctive in man. On the other hand a belief in all-pervading
spiritual agencies seems to be universal; and apparently follows from a
considerable advance in man's reason, and from a still greater advance in
his faculties of imagination, curiosity and wonder. I am aware that the
assumed instinctive belief in God has been used by many persons as an
argument for His existence. But this is a rash argument, as we should thus
be compelled to believe in the existence of many cruel and malignant
spirits, only a little more powerful than man; for the belief in them is
far more general than in a beneficent Deity. The idea of a universal and
beneficent Creator does not seem to arise in the mind of man, until he has
been elevated by long-continued culture.
He who believes in the advancement of man from some low organised form,
will naturally ask how does this bear on the belief in the immortality of
the soul. The barbarous races of man, as Sir J. Lubbock has shewn, possess
no clear belief of this kind; but arguments derived from the primeval
beliefs of savages are, as we have just seen, of little or no avail. Few
persons feel any anxiety from the impossibility of determining at what
precise period in the development of the individual, from the first trace
of a minute germinal vesicle, man becomes an immortal being; and there is
no greater cause for anxiety because the period cannot possibly be
determined in the gradually ascending organic scale. (2. The Rev. J.A.
Picton gives a discussion to this effect in his 'New Theories and the Old
Faith,' 1870.)
I am aware that the conclusions arrived at in this work will be denounced
by some as highly irreligious; but he who denounces them is bound to shew
why it is more irreligious to explain the origin of man as a distinct
species by descent from some lower form, through the laws of variation and
natural selection, than to explain the birth of the individual through the
laws of ordinary reproduction. The birth both of the species and of the
individual are equally parts of that grand sequence of events, which our
minds refuse to accept as the result of blind chance. The understanding
revolts at such a conclusion, whether or not we are able to believe that
every slight variation of structure, - the union of each pair in marriage,
the dissemination of each seed, - and other such events, have all been
ordained for some special purpose.
Sexual selection has been treated at great length in this work; for, as I
have attempted to shew, it has played an important part in the history of
the organic world. I am aware that much remains doubtful, but I have
endeavoured to give a fair view of the whole case. In the lower divisions
of the animal kingdom, sexual selection seems to have done nothing: such
animals are often affixed for life to the same spot, or have the sexes
combined in the same individual, or what is still more important, their
perceptive and intellectual faculties are not sufficiently advanced to
allow of the feelings of love and jealousy, or of the exertion of choice.
When, however, we come to the Arthropoda and Vertebrata, even to the lowest
classes in these two great Sub-Kingdoms, sexual selection has effected
much.
In the several great classes of the animal kingdom, - in mammals, birds,