17. 11. 2020

The Origin of Species

by Charles Darwin


Wallace himself rightly styled Darwin “the Newton of Natural History,” or, as we should now say, of Biology. (Thursday, September 12, 2013, 04:26 PM, page 81)

diversification is itself a biological advantage, since it enables a given area to support a greater bulk of living matter, and in general makes it possible for life to exploit the resources of the environment more fully. (Sunday, September 15, 2013, 04:21 PM, page 98-99)

we should not expect all groups and types of organisms to evolve in the direction of higher organization. Thus single-celled forms, through the very fact of their small size and rapid reproduction, fill a certain natural niche more successfully than larger multicellular creatures can do. (Sunday, September 15, 2013, 04:22 PM, page 100-102)

It further emerged that man constitutes the latest dominant group, and is today, thanks to his new method of evolving by the cumulative transmission of experience, the only type capable of realizing important new possibilities and of achieving further major advances in the future. (Sunday, September 15, 2013, 04:36 PM, page 183-85)

Breeders believe that long limbs are almost always accompanied by an elongated head. (Wednesday, September 25, 2013, 10:08 AM, page 486)

thus cats which are entirely white and have blue eyes are generally deaf; but it has been lately stated by Mr. Tait that this is confined to the males. (Wednesday, September 25, 2013, 10:09 AM, page 487-88)

With animals this kind of selection is, in fact, likewise followed; for hardly any one is so careless as to breed from his worst animals. (Saturday, September 28, 2013, 10:48 AM, page 769)

We see the value set on animals even by the barbarians of Tierra del Fuego, by their killing and devouring their old women, in times of dearth, as of less value than their dogs. (Saturday, September 28, 2013, 11:05 AM, page 819-20)

But, in fact, a breed, like a dialect of a language, can hardly be said to have a distinct origin. (Saturday, September 28, 2013, 11:17 AM, page 863-64)

A large number of individuals of an animal or plant can be reared only where the conditions for its propagation are favourable. (Saturday, September 28, 2013, 11:21 AM, page 880-81)

With animals, facility in preventing crosses is an important element in the formation of new races,—at least, in a country which is already stocked with other races. In this respect enclosure of the land plays a part. (Saturday, September 28, 2013, 11:26 AM, page 888-90)

“there is no possible test but individual opinion to determine which of them shall be considered as species and which as varieties.” (Saturday, September 28, 2013, 06:59 PM, page 1019-20)

A wide distance between the homes of two doubtful forms leads many naturalists to rank them as distinct species; but what distance, it has been well asked, will suffice; if that between America and Europe is ample, will that between Europe and the Azores, or Madeira, or the Canaries, or between the several islets of these small archipelagos, be sufficient? (Saturday, September 28, 2013, 07:01 PM, page 1029-32)

Mr. Walsh ranks the forms which it may be supposed would freely intercross, as varieties; and those which appear to have lost this power, as species. (Saturday, September 28, 2013, 07:03 PM, page 1039-40)

On the other hand, if we look at each species as a special act of creation, there is no apparent reason why more varieties should occur in a group having many species, than in one having few. (Saturday, September 28, 2013, 10:01 PM, page 1147-48)

the amount of difference considered necessary to give to any two forms the rank of species cannot be defined. (Monday, September 30, 2013, 09:09 AM, page 1194)

in short, we see beautiful adaptations everywhere and in every part of the organic world. (Monday, September 30, 2013, 09:12 AM, page 1218-19)

All these results, as we shall more fully see in the next chapter, follow from the struggle for life. (Monday, September 30, 2013, 09:13 AM, page 1222)

expression often used by Mr. Herbert Spencer of the Survival of the Fittest is more accurate, (Monday, September 30, 2013, 09:14 AM, page 1227-28)

A large number of eggs is of some importance to those species which depend on a fluctuating amount of food, for it allows them rapidly to increase in number. But the real importance of a large number of eggs or seeds is to make up for much destruction at some period of life; (Tuesday, October 01, 2013, 07:30 PM, page 1288-90)

Nevertheless, so profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to desolate the world, or invent laws on the duration of the forms of life! (Thursday, October 03, 2013, 09:03 AM, page 1379-81)

Newman says, “Near villages and small towns I have found the nests of humble-bees more numerous than elsewhere, which I attribute to the number of cats that destroy the mice.” (Thursday, October 03, 2013, 09:07 AM, page 1394-95)

But how false a view is this! (Thursday, October 03, 2013, 09:08 AM, page 1400-1401)

What natural selection cannot do, is to modify the structure of one species, without giving it any advantage, for the good of another species; and though statements to this effect may be found in works of natural history, I cannot find one case which will bear investigation. (Monday, October 07, 2013, 08:20 AM, page 1571-73)

with animals and plants a cross between different varieties, or between individuals of the same variety but of another strain, gives vigour and fertility to the offspring; and on the other hand, that close interbreeding diminishes vigour and fertility; (Wednesday, October 09, 2013, 08:10 AM, page 1738-39)

I have not found a single terrestrial animal which can fertilise itself. (Wednesday, October 09, 2013, 12:19 PM, page 1787-88)

Of aquatic animals, there are many self-fertilising hermaphrodites; but here the currents of water offer an obvious means for an occasional cross. (Wednesday, October 09, 2013, 12:20 PM, page 1791-92)

it appears that with animals and plants an occasional intercross between distinct individuals is a very general, if not universal, law of nature. (Wednesday, October 09, 2013, 12:23 PM, page 1800-1801)

the mature animal cannot be called higher than its larva. (Friday, October 11, 2013, 02:19 PM, page 2143-44)

caves, as did European animals into the caves of Europe. We have some evidence of this gradation of habit; for, as Schiödte remarks, “We accordingly look upon the subterranean faunas as small ramifications which have penetrated into the earth from the geographically limited (Sunday, October 20, 2013, 09:27 AM, page 2381-83)

the lower jaw is believed by some anatomists to be homologous with the limbs. (Monday, October 21, 2013, 10:42 AM, page 2456-57)

some other facts, may be merged under a more general principle, namely, that natural selection is continually trying to economise every part of the organisation. (Monday, October 21, 2013, 08:00 PM, page 2510-11)

secondary sexual characters, used by Hunter, relates to characters which are attached to one sex, but are not directly connected with the act of reproduction. (Monday, October 21, 2013, 08:06 PM, page 2546-47)

When we see any part or organ developed in a remarkable degree or manner in a species, the fair presumption is that it is of high importance to that species: nevertheless it is in this case eminently liable to variation. (Monday, October 21, 2013, 08:15 PM, page 2560-62)

I have collected a long list of such cases; but here, as before, I lie under the great disadvantage of not being able to give them. (Tuesday, October 22, 2013, 07:51 AM, page 2700-2701)

But this view may be safely rejected; (Tuesday, October 22, 2013, 06:30 PM, page 2728)

Thus extinction and natural selection go hand in hand. (Wednesday, October 23, 2013, 06:45 AM, page 2816)

the old saying of Vox populi, vox Dei, as every philosopher knows, cannot be trusted in science. (Wednesday, October 23, 2013, 03:07 PM, page 3002-3)

some of the lowest organisms, in which nerves cannot be detected, are capable of perceiving light, (Wednesday, October 23, 2013, 03:08 PM, page 3008)

distincter image. (Wednesday, October 23, 2013, 03:25 PM, page 3056)

If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. (Thursday, October 24, 2013, 08:48 AM, page 3061-62)

Milne Edwards has well expressed it, Nature is prodigal in variety, but niggard in innovation. (Friday, October 25, 2013, 08:59 AM, page 3246)

we know that the distribution and existence of cattle and other animals in South America absolutely depend on their power of resisting the attacks of insects: so that individuals which could by any means defend themselves from these small enemies, would be able to range into new pastures and thus gain a great advantage. (Friday, October 25, 2013, 02:56 PM, page 3260-62)

I have come to this conclusion from finding it an invariable rule that when a flower is fertilised by the wind it never has a gaily-coloured corolla. (Friday, October 25, 2013, 04:37 PM, page 3334-35)

Natural selection cannot possibly produce any modification in a species exclusively for the good of another species; though throughout nature one species incessantly takes advantage of, and profits by, the structures of others. (Friday, October 25, 2013, 04:43 PM, page 3354-55)

Although many statements may be found in works on natural history to this effect, I cannot find even one which seems to me of any weight. (Monday, October 28, 2013, 01:48 PM, page 3358-59)

old canon in natural history, “Natura non facit saltum.” (Monday, October 28, 2013, 02:09 PM, page 3435-36)

Hence it is that existing species during the early stages of their development so often resemble ancient and extinct forms belonging to the same class. (Monday, October 28, 2013, 05:52 PM, page 4126-27)

With cats, for instance, one naturally takes to catching rats, and another mice, and these tendencies are known to be inherited. (Tuesday, October 29, 2013, 02:03 PM, page 4220-21)

Le Roy describes a dog, whose great-grandfather was a wolf, and this dog showed a trace of its wild parentage only in one way, by not coming in a straight line to his master, when called. (Tuesday, October 29, 2013, 02:28 PM, page 4238-39)

the slave-making instinct of certain ants; and the cell-making power of the hive-bee. These two latter instincts have generally and justly been ranked by naturalists as the most wonderful of all known instincts. (Tuesday, October 29, 2013, 02:36 PM, page 4272-73)

Beyond this stage of perfection in architecture, natural selection could not lead; for the comb of the hive-bee, as far as we can see, is absolutely perfect in economising labour and wax. (Wednesday, November 06, 2013, 09:12 AM, page 4558-59)

It will indeed be thought that I have an overweening confidence in the principle of natural selection, when I do not admit that such wonderful and well-established facts at once annihilate the theory. (Wednesday, November 06, 2013, 06:17 PM, page 4633-35)

It is an old and almost universal belief founded on a considerable body of evidence, which I have elsewhere given, that slight changes in the conditions of life are beneficial to all living things. (Monday, November 11, 2013, 08:50 PM, page 5018-20)

Sir Charles Lyell’s grand work on the Principles of Geology, which the future historian will recognise as having produced a revolution in natural science, (Monday, November 11, 2013, 11:13 PM, page 5302-3)

have been stript (Thursday, November 14, 2013, 09:55 AM, page 5447)

If we take a genus having a score of species, recent and extinct, and destroy four-fifths of them, no one doubts that the remainder will stand much more distinct from each other. (Saturday, November 23, 2013, 09:12 AM, page 5563-64)

how doubtful the data are; (Saturday, November 23, 2013, 10:52 AM, page 5681)

Not very long ago M. Barrande added another and lower stage, abounding with new and peculiar species, beneath the then known Silurian system; and now, still lower down in the Lower Cambrian formation, (Saturday, November 23, 2013, 10:54 AM, page 5691-92)

The Eozoon belongs to the most lowly organised of all classes of animals, but is highly organised for its class; it existed in countless numbers, and, as Dr. Dawson has remarked, certainly preyed on other minute organic beings, which must have lived in great numbers. (Saturday, November 23, 2013, 01:53 PM, page 5697-99)

under nature we have every reason to believe that parent-forms are generally supplanted and exterminated by their improved offspring, (Saturday, November 23, 2013, 05:23 PM, page 5793-94)

rarity precedes extinction; (Tuesday, November 26, 2013, 08:50 AM, page 5852)

Buckland long ago remarked, extinct species can all be classed either in still existing groups, or between them. (Thursday, November 28, 2013, 09:57 AM, page 5965-66)

The geological record, at all times imperfect, does not extend far enough back to show with unmistakable clearness that within the known history of the world organisation has largely advanced. (Saturday, November 30, 2013, 06:25 AM, page 6098-99)

the oldest known mammals, reptiles, (Saturday, November 30, 2013, 07:17 PM, page 6132)

Extinct and ancient animals resemble to a certain extent the embryos of the more recent animals belonging to the same classes, and this wonderful fact receives a simple explanation according to our views. (Saturday, November 30, 2013, 09:02 PM, page 6221-23)

A region now impassable to certain organisms from the nature of its climate, might have been a high road for migration, when the climate was different. (Monday, December 02, 2013, 09:58 AM, page 6366-67)

on this average, the seeds of 14/100 plants belonging to one country might be floated across 924 miles of sea to another country, and when stranded, if blown by an inland gale to a favorable spot, would germinate. (Monday, December 02, 2013, 01:11 PM, page 6411-12)

Drift timber is thrown up on most islands, even on those in the midst of the widest oceans; and the natives of the coral-islands in the Pacific procure stones for their tools, solely from the roots of drifted trees, these stones being a valuable royal tax. (Monday, December 02, 2013, 01:14 PM, page 6422-24)

we may almost conclude, without other evidence, that a colder climate formerly permitted their migration across the intervening lowlands, now become too warm for their existence. , (Monday, December 02, 2013, 09:10 PM, page 6530-31)

twenty-five species of Algae are common to New Zealand and to Europe, but have not been found in the intermediate tropical seas. (Tuesday, December 03, 2013, 08:46 AM, page 6650-51)

Mountains are islands on the land, (Tuesday, December 03, 2013, 07:57 PM, page 6699)

tablespoonfuls (Tuesday, December 03, 2013, 11:58 PM, page 6784)

Potamogeton. (Tuesday, December 03, 2013, 11:59 PM, page 6790-91)

the number even in a well-stocked pond is small in comparison with the number of species inhabiting an equal area of land, (Wednesday, December 04, 2013, 09:08 AM, page 6799-6800)

within each great class the lower organisms change at a slower rate than the higher; consequently they will have had a better chance of ranging widely and of still retaining the same specific character. (Sunday, December 08, 2013, 06:48 PM, page 7029-31)

difficulties are far from insuperable; (Monday, December 09, 2013, 09:24 AM, page 7049)

the discovery of Australia has not added an insect belonging to a new class; and that in the vegetable kingdom, as I learn from Dr. Hooker, it has added only two or three families of small size. (Wednesday, December 11, 2013, 09:14 AM, page 7385-87)

at whatever age a variation first appears in the parent, it tends to re-appear at a corresponding age in the offspring. (Monday, December 16, 2013, 06:20 PM, page 7635-36)

As the embryo often shows us more or less plainly the structure of the less modified and ancient progenitor of the group, we can see why ancient and extinct forms so often resemble in their adult state the embryos of existing species of the same class. (Monday, December 16, 2013, 08:59 PM, page 7724-25)

manatee have been developed for this same purpose. (Tuesday, December 17, 2013, 09:56 PM, page 7802-3)

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. (Wednesday, December 18, 2013, 09:19 AM, page 7839-40)

With respect to existing forms, we should remember that we have no right to expect (excepting in rare cases) to discover directly connecting links between them, but only between each and some extinct and supplanted form. (Friday, December 20, 2013, 01:01 AM, page 7930-32)

I have felt these difficulties far too heavily during many years to doubt their weight. But it deserves especial notice that the more important objections relate to questions on which we are confessedly ignorant; nor do we know how ignorant we are. (Friday, December 20, 2013, 11:49 AM, page 7981-83)

Great is the power of steady misrepresentation; but the history of science shows that fortunately this power does not long endure. (Monday, December 23, 2013, 08:49 PM, page 8195-96)

But the chief cause of our natural unwillingness to admit that one species has given birth to clear and distinct species, is that we are always slow in admitting great changes of which we do not see the steps. (Monday, December 23, 2013, 08:54 PM, page 8215-16)

A few naturalists, endowed with much flexibility of mind, and who have already begun to doubt the immutability of species, may be influenced by this volume; but I look with confidence to the future,—to young and rising naturalists, who will be able to view both sides of the question with impartiality. (Monday, December 23, 2013, 08:56 PM, page 8224-26)

I believe that animals are descended from at most only four or five progenitors, and plants from an equal or lesser number. (Monday, December 23, 2013, 09:04 PM, page 8260)

When the views advanced by me in this volume, and by Mr. Wallace, or when analogous views on the origin of species are generally admitted, we can dimly foresee that there will be a considerable revolution in natural history. (Monday, December 23, 2013, 09:09 PM, page 8276-77)

imbedded (Monday, December 23, 2013, 11:03 PM, page 8312)