The Descent of Man

and Selection in Relation to Sex

Charles Darwin

(London: John Murray, 2nd rev. ed: 1877)


Part I: The Descent or Origin of Man

Chapter I: The Evidence of The Descent of Man From Some Lower Form.

Nature of the evidence bearing on the origin of man--Homologous structures in man and the lower animals--Miscellaneous points of correspondence--Development--Rudimentary structures, muscles, sense-organs, hair, bones, reproductive organs, etc.--The bearing of these three great classes of facts on the origin of man

Chapter II: On The Manner of Development of Man From Some Lower Form.

Variability of body and mind in man--Inheritance--Causes of variability--Laws of variation the same in man as in the lower animals--Direct action of the conditions of life--Effects of the increased use and disuse of parts--Arrested development--Reversion--Correlated variation--Rate of increase--Checks to increase--Natural selection--Man the most dominant animal in the world--Importance of his corporeal structure--The causes which have led to his becoming erect--Consequent changes of structure--Decrease in size of the canine teeth--Increased size and altered shape of the skull--Nakedness--Absence of a tail--Defenceless condition of man

Chapter III: Comparison of The Mental Powers of Man and the Lower Animals.

The difference in mental power between the highest ape and the lowest savage, immense--Certain instincts in common--The emotions--Curiosity--Imitation--Attention--Memory--Imagination--Reason--Progressve Improvement--Tools and weapons used by animals--Abstraction, self-consciousness--Language--Sense of beauty--Belief in God, spiritual agencies, superstitions

Chapter IV: Comparison of the Mental Powers of Man and the Lower Animals (Continued).

The moral sense--Fundamental proposition--The qualities of social animals--Origin of sociability--Struggle between opposed instincts--Man a social animal--The more enduring social instincts conquer other less persistent instincts--The social virtues alone regarded by savages--The self-regarding virtues acquired at a later stage of development--The importance of the judgment of the members of the same community on conduct--Transmission of moral tendencies--Summary

Chapter V: On The Development of The Intellectual and Moral Faculties During Primaeval and Civilized Times.

Advancement of the intellectual powers through natural selection--Importance of imitation--Social and moral faculties--Their development within the limits of the same tribe--Natural selection as affecting civilized nations--Evidence that civilized nations were once barbarous

Chapter VI: On the Affinities and Genealogy of Man.

Position of man in the animal series--The natural system genealogical--Adaptive characters of slight value--Various small points of resemblance between man and the Quadrumana--Rank of man in the natural system--Birthplace and antiquity of man--Absence of fossil connecting-links--Lower stages in the genealogy of man, as inferred, first, from his affinities, and, secondly, from his structure--Early androgynous condition of the Vertebrata--Conclusion

Chapter VII: On the Races of Man.

The nature and value of specific characters--Application to the races of man--Arguments in favor of, and opposed to, ranking the so-called races of man as distinct species--Sub-species--Monogenists and polygenists--Convergence of character--Numerous points of resemblance in body and mind between the most distinct races of man--The state of man when he first spread over the earth--Each race not descended from a single pair--The extinction of races--The formation of races--The effects of crossing--Slight influence of the direct action of the conditions of life-Slight or no influence of natural selection--Sexual selection

Part II: : Sexual Selection

Chapter VIII: Principles of Sexual Selection.

Secondary sexual characters--Sexual selection--Manner of action--Excess of males--Polygamy--The male alone generally modified through sexual selection--Eagerness of the male--Variability of the male--Choice exerted by the female--Sexual compared with natural selection--Inheritance, at corresponding periods of life, at corresponding seasons of the year, and as limited by sex--Relations between the several forms of inheritance--Causes why one sex and the young are not modified through sexual selection--Supplement on the proportional numbers of the two sexes throughout the animal kingdom--The proportion of the sexes in relation to natural selection

Chapter IX: Secondary Sexual Characters in The Lower Classes of the Animal Kingdom.

These characters absent in the lowest classes--Brilliant colors--Mollusca--Annelids--Crustacea, secondary sexual characters strongly developed; dimorphism; color; characters not acquired before maturity--Spiders, sexual colors of; stridulation by the males--Myriapoda

Chapter X: Secondary Sexual Characters of Insects.

Diversified structures possessed by the males for seizing the females- Differences between the sexes, of which the meaning is not under stood--Difference in size between the sexes--Thysanura--Diptera--Hemiptera--Homoptera, musical powers possessed by the males alone--Orthoptera, musical Instruments of the males, much diversified in structure; pugnacity; colors--Xeuroptels, sexual differences In color--Hymenoptera, pugnacity and colors-Coleoptera, colors; furnished with great horns, apparently as an ornament; battles; stridulating organs generally common to both sexes

Chapter XI: Insects, Continued--Order Lepidoptera (Butterflies and Moths).

Courtship of butterflies--Battles--Ticking noise--Colors common to both sexes, or more brilliant in the males--Examples--Not due to the direct action of the conditions of life--Colors adapted for protection--Colors of moths--Display--Perceptive powers of the Lepidoptera--Variability--Causes of the difference in color between the males and females--Mimicry, female butterflies more brilliantly colored than the males--Bright colors of caterpillars--Summary and concluding remarks on the secondary sexual characters of insects--Birds and insects compared

Chapter XII: Secondary Sexual Characaters of Fishes, Amphibians, and Reptiles.

FISHES: Courtship and battles of the males--Larger size of the females--Males, bright colors and ornamental appendages; other strange characters--Colors and appendages acquired by the males during the breeding season alone--Fishes with both sexes brilliantly colored--Protective colors--The less conspicuous colors of the female cannot be accounted for on the principle of protection--Male fishes building nests, and taking charge of the ova and young.--AMPHIBIANS: Differences in structure and color between the sexes--Vocal organs--REPTILES: Chelonians--Crocodiles--Snakes, colors in some cases protective--Lizards, battles of--Ornamental appendages--Strange differences in structure between the sexes--Colors--Sexual differences almost as great as with birds

Chapter XIII: Secondary Sexual Characters of Birds.

Sexual differences--Law of battle--Special weapons--Vocal organs--Instrumental music--Love-antics and dances--Decorations, permanent and seasonal--Double and single annual moults--Display of ornaments by the males

Chapter XIV: Birds--Continued.

Choice exerted by the female--Length of courtship--Unpaired birds--Mental qualities and taste for the beautiful--Preference or antipathy shown by the female for particular males--Variability of birds--Variations sometimes abrupt--Laws of variation--Formation of ocelli--Gradations of character--Case of Peacock, Argus pheasant, and Urosticte

Chapter XV: Birds--Continued.

Discussion as to why the males alone of some species, and both sexes of others, are brightly colored--On sexually limited inheritance, as applied to various structures and to brightly colored plumage--Nidification in relation to color--Loss of nuptial plumage during the winter

Chapter XVI: Birds--Concluded.

The immature plumage in relation to the character of the plumage in both sexes when adult--Six classes of cases--Sexual differences between the males of closely allied or representative species--The female assuming the characters of the male--Plumage of the young in relation to the summer and winter plumage of the adults--On the increase of beauty in the birds of the world--Protective coloring--Conspicuously colored birds--Novelty appreciated--Summary of the four chapters on birds

Chapter XVII: Secondary Sexual Characters or Mammals.

The law of battle--Special weapons, confined to the males--Cause of absence of weapons in the female--Weapons common to both sexes, yet primarily acquired by the male--Other uses of such weapons- Their high importance--Greater size of the male--Means of defence--On the preference shown by either sex in the pairing of quadrupeds

Chapter XVIII: Secondary Sexual Characters of Mammals--Continued.

Voice--Remarkable sexual peculiarities in seals--Odor--Development of the hair--Color of the hair and skin--Anomalous case of the female being more ornamented than the male--Color and ornaments due to sexual selection--Color acquired for the sake of protection--Color, though common to both sexes, often due to sexual selection--On the disappearance of spots and stripes in adult quadrupeds--On the colors and ornaments of the Quadrumana--Summary

Part III: : Sexual Selection in Relation to Man and Conclusion

Chapter XIX: Secondary Sexual Characters of Man.

Differences between man and woman--Causes of such differences and of certain characters common to both sexes--Law of battle--Differences in mental powers, and voice--On the influence of beauty in determining the marriages of mankind--Attention paid by savages to ornaments--Their ideas of beauty in woman--The tendency to exaggerate each natural peculiarity

Chapter XX: Secondary Sexual Characters of Man--Continued.

On the effects of the continued selection of women according to a different standard of beauty in each race--On the causes which interfere with sexual selection in civilized and savage nations--Conditions favorable to sexual selection during primeval times--On the manner of action of sexual selection with mankind--On the women in savage tribes having some power to choose their husbands--Absence of hair on the body, and development of the beard--Color of the skin--Summary

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