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OriginOfSpecies - 475 Rows
Column Type #Values Column Stats
id int(11) 475 Column Stats
subject varchar(80) 14 Column Stats
title varchar(250) 139 Column Stats
ordinal int(11) 30 Column Stats
description text 474 Column Stats

475 rows, page 21 of 119 (4/p)
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Export to Excel select * from OriginOfSpecies order by subject, title, ordinal limit 80, 4 (Page 21: Row)
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03 - Struggle for Existence 03-02 - The Term, Struggle for Existence, used in a large sense 20 I should premise that I use this term in a large and metaphorical sense including dependence of one being on another, and including (which is more important) not only the life of the individual, but success in leaving progeny.

Two canine animals, in a time of dearth may be truly said to struggle with each other which shall get food and live.

canine
canine


But a plant on the edge of a desert is said to struggle for life against the drought, though more properly it should be said to produces a thousand seeds, of which only one of an average comes to maturity, may be more truly said to struggle with the plants of the same and other kinds which already clothe the ground.

The mistletoe is dependent on the apple and a few other trees, but can only in a far-fetched sense be said to struggle with these trees, for, if too many of these parasites grow on the same tree, it languishes and dies.

mistletoe
mistletoe

apple
apple


But several seedling mistletoes, growing close together on the same branch, may more truly be said to struggle with each other. As the mistletoe is disseminated by birds, its existence depends on them; and it may methodically be said to struggle with other fruit-bearing plants, in tempting the birds to devour and thus disseminate its seeds. In these several senses, which pass into each other, I use for convenience' sake the general term of Struggle for Existence.

mistletoe
mistletoe

bird
bird
03 - Struggle for Existence 03-03 - Geometrical Ratio of Increase 10 A struggle for existence inevitably follows from the high rate at which all organic beings tend to increase.

Every being, which during its natural lifetime produces several eggs or seeds, must suffer destruction during some period of its life, and during some season or occasional year, otherwise, on the principle of geometrical increase, its numbers would quickly become so inordinately great that no country could support the product.

egg
egg

seeds
seeds


Hence, as more individuals are produced than can possibly survive, there must in every case be a struggle for existence, either one individual with another of the same species, or with the individuals of distinct species, or with the physical conditions of life.

It is the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms; for in this case there can be no artificial increase of food, and no prudential restraint from marriage.

Although some species may be now increasing, more or less rapidly, in numbers, all cannot do so, for the world would not hold them.
03 - Struggle for Existence 03-03 - Geometrical Ratio of Increase 20 There is no exception to the rule that every organic being naturally increases at so high a rate, that, if not destroyed, the earth would soon be covered by the progeny of a single pair.

Earth
Earth


Even slow-breeding man has doubled in twenty-five years, and at this rate, in less than a thousand years, there would literally not be standing-room for his progeny.

Ape Man
Ape Man


Linnaeus has calculated that if an annual plant produced only two seeds- and there is no plant so unproductive as this- and their seedlings next year produced two, and so on, then in twenty years there should be a million plants.

The elephant is reckoned the slowest breeder of all known animals, and I have taken some pains to estimate its probable minimum rate of natural increase; it will be safest to assume that it begins breeding when thirty years old, and goes on breeding till ninety years old, bringing forth six young in the interval, and surviving till one hundred years old; if this be so, after a period of from 740 to 750 years there would be nearly nineteen million elephants alive, descended from the first pair.

elephant
elephant

Orangutan
Orangutan
03 - Struggle for Existence 03-04 - Rapid Increase of naturalised Animals and Plants 10 But we have better evidence on this subject than mere theoretical calculations, namely, the numerous recorded cases of the astonishingly rapid increase of various animals in a state of nature, when circumstances have been favourable to them during two or three following seasons.

Still more striking is the evidence from our domestic animals of many kinds which have run wild in several parts of the world; if the statements of the rate of increase of slow-breeding cattle and horses in South America, and latterly in Australia, had not been well authenticated, they would have been incredible.

cattle
cattle

horses
horses


So it is with plants; cases could be given of introduced plants which have become common throughout whole islands in a period of less than ten years.

Several of the plants, such as the cardoon and a tall thistle, which are now the commonest over the whole plains of La Plata, clothing square leagues of surface almost to the exclusion of every other plant, have been introduced from Europe; and there are plants which now range in India, as I hear from Dr. Falconer, from Cape Comorin to the Himalaya, which have been imported from America since its discovery.

cardoon
cardoon

thistle
thistle

La Plata
La Plata

Europe
Europe

India
India

Cape Comorin
Cape Comorin

Himalaya
Himalaya

America
America


In such cases, and endless others could be given, no one supposes that the fertility of the animals or plants has been suddenly and temporarily increased in any sensible degree.

The obvious explanation is that the conditions of life have been highly favourable, and that there has consequently been less destruction of the old and young, and that nearly all the young have been enabled to breed.

Their geometrical ratio of increase, the result of which never fails to be surprising, simply explains their extraordinarily rapid increase and wide diffusion in their new homes.