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F387    Book:     Darwin, C. R. 1869. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 5th ed. Tenth thousand.   Text   Image   PDF
other such cases, is intelligible, for generally within the same country, the existing and the extinct will be closely allied by descent. Looking to geographical distribution, if we admit that there has been during the long course of ages much migration from one part of the world to another, owing to former climatal and geographical changes and to the many occasional and unknown means of dispersal, then we can understand, on the theory of descent with modification, most of the great leading facts
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F387    Book:     Darwin, C. R. 1869. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 5th ed. Tenth thousand.   Text   Image   PDF
inexplicable on the theory of independent acts of creation. The existence of closely allied or representative species in any two areas, implies, on the theory of descent with modification, that the same parent-forms formerly inhabited both areas; and we almost invariably find that wherever many closely allied species inhabit two [page] 56
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F387    Book:     Darwin, C. R. 1869. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 5th ed. Tenth thousand.   Text   Image   PDF
sophical axiom of least action leads the mind more willingly to admit the smaller number; and certainly we ought not to believe that innumerable beings within each great class have been created with plain, but deceptive, marks of descent from a single parent. It may be asked how far I extend the doctrine of the modification of species. The question is difficult to answer, because the more distinct the forms are which we consider, by so much the arguments fall away in force. But some arguments
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F387    Book:     Darwin, C. R. 1869. On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 5th ed. Tenth thousand.   Text   Image   PDF
opinion it has done excellent service in this country in calling attention to the subject, in removing prejudice, and in thus preparing the ground for the reception of analogous views. In 1846 the veteran geologist M. J. d'Omalius d'Halloy published in an excellent, though short paper ('Bulletins de l'Acad. Roy. Bruxelles,' tom. xiii. p. 581), his opinion that it is more probable that new species have been produced by descent with modification, than that they have been separately created: the author
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A576    Pamphlet:     Wright, Chauncey. 1871. Darwinism: Being an examination of Mr. St. George Mivart's 'Genesis of species,' [Reprinted from the 'North American Review,' July 1871, with additions]. London: John Murray. 46pp.   Text   Image
processes by which races of animals and plants have been derived by descent from different ancestral forms. What is no longer regarded with suspicion as secretly hostile to religious beliefs by many truly religious thinkers is that which is denoted in common by the various names transmutation, development, derivation, evolution, and descent with modification. These terms are synonymous in their primary and general signification, but refer secondarily to various hypotheses of the processes of
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A576    Pamphlet:     Wright, Chauncey. 1871. Darwinism: Being an examination of Mr. St. George Mivart's 'Genesis of species,' [Reprinted from the 'North American Review,' July 1871, with additions]. London: John Murray. 46pp.   Text   Image
the theological critics of the theory, but to its scientific advocates; although, from the neutral ground of experimental science, descent with modification is the most pertinent and least exceptionable name. While the general doctrine of evolution has thus been successfully redeemed from theological condemnation, this is not yet true of the subordinate hypothesis of Natural Selection, to the partial success of which this change of opinion is, in great measure, due. It is, at first sight a
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
CHAPTER XIV. MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY: EMBRYOLOGY: RUDIMENTARY ORGANS. CLASSIFICATION, groups subordinate to groups — Natural system — Rules and difficulties in classification, explained on the theory of descent with modification — Classification of varieties — Descent always used in classification — Analogical or adaptive characters — Affinities, general, complex and radiating — Extinction separates and defines groups — MORPHOLOGY, between members of the same class
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
, undergoing modification during their migration, from some one area. If, when most of the species inhabiting one region are different from those of another region, though closely allied to them, it can be shown that migration from the one region to the other has probably occurred at some former period, our general view will be much strengthened; for the explanation is obvious on the principle of descent with modification. A volcanic island, for instance, upheaved and formed at the distance of a few
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
. DIFFICULTIES OF THE THEORY. Difficulties of the theory of descent with modification — Absence or rarity of transitional varieties — Transitions in habits of life — Diversified habits in the same species — Species with habits widely different from those of their allies — Organs of extreme perfection — Modes of transition — Cases of difficulty — Natura non facit saltum — Organs of small importance — Organs not in all cases absolutely perfect — The law of Unity of Type and of the Conditions of Existence
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
('Bulletins de l'Acad. Roy. Bruxelles, tom. xiii. p. 581), his opinion that it is more probable that new species have been produced by descent with modification than that they have been separately created: the author first promulgated this opinion in 1831. Professor Owen, in 1849 ('Nature of Limbs,' p. 86), wrote as follows:— The archetypal idea was manifested in the flesh under diverse such modifications, upon this planet, long prior to the existence of those animal species that actually exemplify
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
CHAPTER VI. DIFFICULTIES OF THE THEORY. Difficulties of the theory of descent with modification — Absence or rarity of transitional varieties — Transitions in habits of life — Diversified habits in the same species — Species with habits widely different from those of their allies — Organs of extreme perfection — Modes of transition — Cases of difficulty — Natura non facit saltum — Organs of small importance — Organs not in all cases absolutely perfect — The law of Unity of Type and of the
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
having affinities directed towards very distinct groups. Yet if we compare the older Reptiles and Batrachians, the older Fish, the older Cephalopods, and the eocene Mammals, with the more recent members of the same classes, we must admit that there is truth in the remark. Let us see how far these several facts and inferences accord with the theory of descent with modification. As the subject is somewhat complex, I must request the reader to turn to the diagram in the fourth chapter. We may suppose
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
, within known geological periods, undergone much modification, should in the older formations make some slight approach to each other; so that the older members should differ less from each other in some of their characters than do the existing members of the same groups; and this by the concurrent evidence of our best palæontologists is frequently the case. Thus, on the theory of descent with modification, the main facts with respect to the mutual affinities of the extinct forms of life to
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
where our oscillating continents now stand they have stood since the commencement of the Cambrian system; but that, long before that epoch, the world presented a widely different aspect; and that the older continents, formed of formations older than any known to us, exist now only as remnants in a metamorphosed condition, or lie still buried under the ocean. Passing from these difficulties, the other great leading facts in palæontology agree admirably with the theory of descent with
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
difficulties, but it does not accord with all the facts in regard to the productions of islands. In the following remarks I shall not confine myself to the mere question of dispersal, but shall consider some other cases bearing on the truth of the two theories of independent creation and of descent with modification. The species of all kinds which inhabit oceanic islands are few in number compared with those on equal continental areas: Alph. de Candolle admits this for plants, and Wollaston for
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
CHAPTER XIV. MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY: EMBRYOLOGY: RUDIMENTARY ORGANS. CLASSIFICATION, groups subordinate to groups — Natural system — Rules and difficulties in classification, explained on the theory of descent with modification — Classification of varieties — Descent always used in classification — Analogical or adaptive characters — Affinities, general, complex, and radiating — Extinction separates and defines groups — MORPHOLOGY, between members of the same class
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
myself, on the view that the Natural System is founded on descent with modification;—that the characters which naturalists consider as showing true affinity between any two or more species, are those which have been inherited from a common parent, all true classification being genealogical;—that community of descent is the hidden bond which naturalists have been unconsciously seeking, and not some unknown plan of creation, or the enunciation of general propositions, and the mere putting together and
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
the genealogical view of classification, how it is that systematists, in placing organisms in their proper places in the natural system, have often found rudimentary parts as useful as, or even sometimes more useful than, parts of high physiological importance. Rudimentary organs may be compared with the letters in a word, still retained in the spelling, but become useless in the pronunciation, but which serve as a clue for its derivation. On the view of descent with modification, we may conclude
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
genealogical in its attempted arrangement, with the grades of acquired difference marked by the terms, varieties, species, genera, families, orders, and classes. On this same view of descent with modification, most of the great facts in Morphology become intelligible,—whether we look to the same pattern displayed by the different species of the same class in their homologous organs, to whatever purpose applied; or to the serial and lateral homologies in each individual animal and plant. On the principle
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
inferences briefly recapitulated. That many and serious objections may be advanced against the theory of descent with modification through variation and natural selection, I do not deny. I have endeavoured to give to them their full force. Nothing at first can appear more difficult to believe than that the more complex organs and instincts have been perfected, not by means superior to, though analogous with, human reason, but by the accumulation of innumerable slight variations, each good for the
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
species had been independently created and varieties had been produced through secondary laws. If we admit that the geological record is imperfect to an extreme degree, then the facts, which the record does give, strongly support the theory of descent with modification. New species have come on the stage slowly and at successive intervals; and the amount of change, after equal intervals of time, is widely different in different groups. The extinction of species and of whole groups of species
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
of ages much migration from one part of the world to another, owing to former climatal and geographical changes and to the many occasional and unknown means of dispersal, then we can understand, on the theory of descent with modification, most of the great leading facts in Distribution. We can see why there should be so striking a parallelism in the distribution of organic beings throughout space, and in their geological succession throughout time; for in both cases the beings have been
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
developed condition; and this in some cases implies an enormous amount of modification in the descendants. Throughout whole classes various structures are formed on the same pattern, and at a very early age the embryos closely resemble each other. Therefore I cannot doubt that the theory of descent with modification embraces all the members of the same great class or kingdom. I believe that animals are descended from at most only four or five progenitors, and plants from an equal or lesser number
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
(I), and the eight descended from (A), will have to be ranked as very distinct genera, or even as distinct sub-families. Thus it is, as I believe, that two or more genera are produced by descent with modification, from two or more species of the same genus. And the two or more parent-species are supposed to be descended from some one species of an earlier genus. In our diagram, this is indicated by the broken lines, beneath the capital letters, converging in sub-branches downwards towards a
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
formerly more closely allied, than it is at present, to the northern half. In a similar manner we know, from Falconer and Cautley's discoveries, that Northern India was formerly more closely related in its mammals to Africa than it is at the present time. Analogous facts could be given in relation to the distribution of marine animals. On the theory of descent with modification, the great law of the long enduring, but not immutable, succession of the same types within the same areas, is at once
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
rudimentary nails on the fin of the manatee have been developed for this same purpose. On the view of descent with modification, the origin of rudimentary organs is comparatively simple; and we can understand to a large extent the laws governing their imperfect development. We have plenty of cases of rudimentary organs in our domestic productions,—as the stump of a tail in tailless breeds,—the vestige of an ear in earless breeds of sheep, the reappearance of minute dangling horns in hornless
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
same time be able to give a definite answer to the question why two distinct species, when crossed, as well as their hybrid offspring, are generally rendered more or less sterile, whilst two domesticated varieties when crossed and their mongrel offspring are perfectly fertile. Turning to geographical distribution, the difficulties encountered on the theory of descent with modification are serious enough. All the individuals of the same species, and all the species of the same genus, or even higher
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F391    Book:     Darwin, C. R. 1872. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed.; with additions and corrections. Eleventh thousand.   Text   Image   PDF
representative species in any two areas, implies, on the theory of descent with modification, that the same parent-forms formerly inhabited both areas: and we almost invariably find that wherever many closely allied species inhabit two areas, some identical species are still common to both. Wherever many closely allied yet distinct species occur, doubtful forms and varieties belonging to the same groups likewise occur. It is a rule of high generality that the inhabitants of each area are related to
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F880.1    Book:     Darwin, C. R. 1875. The variation of animals and plants under domestication. London: John Murray. 2d ed. vol. 1.   Text   Image   PDF
seems to have been unbroken or continuous. New species come in gradually one by one. Ancient and extinct forms of life are often intermediate in character, like the words of a dead language with respect to its several offshoots or living tongues. All these facts seemed to me to point to descent with modification as the means of production of new species. The innumerable past and present inhabitants of the world are connected together by the most singular and complex affinities, and can be classed
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F880.1    Book:     Darwin, C. R. 1875. The variation of animals and plants under domestication. London: John Murray. 2d ed. vol. 1.   Text   Image   PDF
, birds, reptiles, and fish. It is the consideration and explanation of such facts as these which has convinced me that the theory of descent with modification by means of natural selection is in the main true. These facts have as yet received no explanation on the theory of independent Creation; they cannot be grouped together under one point of view, but each has to be considered as an ultimate fact. As the first origin of life on this earth, as well as the continued life of each individual, is at
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F880.2    Book:     Darwin, C. R. 1875. The variation of animals and plants under domestication. London: John Murray. 2d ed. vol. 2.   Text   Image   PDF
retain their former state,—are the same with the parts which differ in the natural species of the same genus. As, on the theory of descent with modification, the species of the same genus have been modified since they branched off from a common progenitor, it follows that the characters by which they differ from one another [page] 3
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F880.1    Book:     Darwin, C. R. 1875. The variation of animals and plants under domestication. London: John Murray. 2d ed. vol. 1.   Text   Image   PDF
similar constitution, and a consequent tendency to vary in the same manner; and those who believe in the general theory of descent with modification may extend this ———————————————— 24 'Considérations sur les Céréales,' 1842-43, p. 29. 25 'Travels in the Himalayan Provinces,' c., 1841, vol. i. p. 224. 26 Col. J. Le Couteur on the 'Varieties of Wheat,' pp. 23, 79. 27 Loiseleur-Deslongchamps, 'Consid. sur les Céréales,' p. 11. 28 See an excellent review in Hooker's 'Journ. of Botany,' vol. viii. p
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F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
, undergoing modification during their migration, from some one area. If, when most of the species inhabiting one region are different from those of another region, though closely allied to them, it can be shown that migration from the one region to the other has probably occurred at some former period, our general view will be much strengthened; for the explanation is obvious on the principle of descent with modification. A volcanic island, for instance, upheaved and formed at the distance of a few
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F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
CHAPTER XIV MUTUAL AFFINITIES OF ORGANIC BEINGS: MORPHOLOGY: EMBRYOLOGY: RUDIMENTARY ORGANS. CLASSIFICATION, groups subordinate to groups Natural system Rules and difficulties in classification, explained on the theory of descent with modification Classification of varieties Descent always used in classification Analogical or adaptive characters Affinities, general, complex, and radiating Extinction separates and defines groups MORPHOLOGY, between members of the same class, between parts of
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F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
with modification Absence or rarity of transitional varieties Transitions in habits of life Diversified habits in the same species Species with habits widely different from those of their allies Organs of extreme perfection Modes of transition Cases of difficulty Natura non facit saltum Organs of small importance Organs not in all cases absolutely perfect The law of Unity of Type and of the Conditions of Existence embraced by the theory of Natural Selection 133-167 [page] vi
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F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
('Bulletins de l'Acad. Roy. Bruxelles, tom. xiii. p. 581), his opinion that it is more probable that new species have been produced by descent with modification than that they have been separately created: the author first promulgated this opinion in 1831. Professor Owen, in 1849 ('Nature of Limbs,' p. 86), wrote as follows: The archetypal idea was manifested in the flesh under diverse such modifications, upon this planet, long prior to the existence of those animal species that actually exemplify
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
CHAPTER VI. DIFFICULTIES OF THE THEORY. Difficulties of the theory of descent with modification Absence or rarity of transitional varieties Transitions in habits of life Diversified habits in the same species Species with habits widely different from those of their allies Organs of extreme perfection Modes of transition Cases of difficulty Natura non facit saltum Organs of small importance Organs not in all cases absolutely perfect The law of Unity of Type and of the Conditions of Existence
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F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
having affinities directed towards very distinct groups. Yet if we compare the older Reptiles and Batrachians, the older Fish, the older Cephalopods, and the eocene Mammals, with the more recent members of the same classes, we must admit that there is truth in the remark. Let us see how far these several facts and inferences accord with the theory of descent with modification. As the subject is somewhat complex, I must request the reader to turn to the diagram in the fourth chapter. We may suppose
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
, within known geological periods, undergone much modification, should in the older formations make some slight approach to each other; so that the older members should differ less from each other in some of their characters than do the existing members of the same groups; and this by the concurrent evidence of our best pal ontologists is frequently the case. Thus, on the theory of descent with modification, the main facts with respect to the mutual affinities of the extinct forms of life to
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
where our oscillating continents now stand they have stood since the commencement of the Cambrian system; but that, long before that epoch, the world presented a widely different aspect; and that the older continents, formed of formations older than any known to us, exist now only as remnants in a metamorphosed condition, or lie still buried under the ocean. Passing from these difficulties, the other great leading facts in pal ontology agree admirably with the theory of descent with
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
difficulties, but it does not accord with all the facts in regard to the productions of islands. In the following remarks I shall not confine myself to the mere question of dispersal, but shall consider some other cases bearing on the truth of the two theories of independent creation and of descent with modification. The species of all kinds which inhabit oceanic islands are few in number compared with those on equal continental areas: Alph. de Candolle admits this for plants, and Wollaston for
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
CHAPTER XIV. Mutual Affinities of Organic Beings: Morphology: Embryology: Rudimentary Organs. Classification, groups subordinate to groups Natural system Rules and difficulties in classification, explained on the theory of descent with modification Classification of varieties Descent always used in classification Analogical or adaptive characters Affinities, general, complex, and radiating Extinction separates and defines groups Morphology, between members of the same class, between parts of
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
myself, on the view that the Natural System is founded on descent with modification; that the characters which naturalists consider as showing true affinity between any two or more species, are those which have been inherited from a common parent, all true classification being genealogical; that community of descent is the hidden bond which naturalists have been unconsciously seeking, and not some unknown plan of creation, or the enunciation of general propositions, and the mere putting together and
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
the genealogical view of classification, how it is that systematists, in placing organisms in their proper places in the natural system, have often found rudimentary parts as useful as, or even sometimes more useful than, parts of high physiological importance. Rudimentary organs may be compared with the letters in a word, still retained in the spelling, but become useless in the pronunciation, but which serve as a clue for its derivation. On the view of descent with modification, we may conclude
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
genealogical in its attempted arrangement, with the grades of acquired difference marked by the terms, varieties, species, genera, families, orders, and classes. On this same view of descent with modification, most of the great facts in Morphology become intelligible, whether we look to the same pattern displayed by the different species of the same class in their homologous organs, to whatever purpose applied; or to the serial and lateral homologies in each individual animal and plant. On the principle
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
briefly recapitulated. That many and serious objections may be advanced against the theory of descent with modification through variation and natural selection, I do not deny. I have endeavoured to give to them their full force. Nothing at first can appear more difficult to believe than that the more complex organs and instincts have been perfected, not by means superior to, though analogous with, human reason, but by the accumulation of innumerable slight variations, each good for the individual
53%
F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
species had been independently created and varieties had been produced through secondary laws. If we admit that the geological record is imperfect to an extreme degree, then the facts, which the record does give, strongly support the theory of descent with modification. New species have come on the stage slowly and at successive intervals; and the amount of change, after equal intervals of time, is widely different in different groups. The extinction of species and of whole groups of species
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F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
of ages much migration from one part of the world to another, owing to former climatal and geographical changes and to the many occasional and unknown means of dispersal, then we can understand, on the theory of descent with modification, most of the great leading facts in Distribution. We can see why there should be so striking a parallelism in the distribution of organic beings throughout space, and in their geological succession throughout time; for in both cases the beings have been
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F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
representative species in any two areas, implies, on the theory of descent with modification, that the same parent-forms formerly inhabited both areas: and we almost invariably find that wherever many closely allied species inhabit two areas, some identical species are still common to both. Wherever many closely allied yet distinct species occur, doubtful forms and varieties belonging to the same groups likewise occur. It is a rule of high generality that the inhabitants of each area are related to
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F401    Book:     Darwin, C. R. 1876. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. London: John Murray. 6th ed., with additions and corrections. [First issue of final definitive text]   Text   Image   PDF
developed condition; and this in some cases implies an enormous amount of modification in the descendants. Throughout whole classes various structures are formed on the same pattern, and at a very early age the embryos closely resemble each other. Therefore I cannot doubt that the theory of descent with modification embraces all the members of the same great class or kingdom. I believe that animals are descended from at most only four or five progenitors, and plants from an equal or lesser number
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