from The Descent of Man, 1871) stayed with him all his life, and was probably one of the factors that caused him to speculate about social behaviors and systems in evolutionary terms.
It is instructive to compare the selections here with Tennyson's In Memoriam, Robert Browning's 'Caliban upon Setebos' (1864), and the extracts from the writings of Huxley.
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CHARLES DARWIN
Charles Darwin (1809?1882) developed an interest in geology and biology at Cambridge, where he was studying to become a clergyman. Aided by a private income, he resolved to devote the rest of his life to scientific research. The observations he made during a long voyage to the South Seas on the HMS Beagle (on which he served as a naturalist) led Darwin to construct hypotheses about evolution. In 1858, more than twenty years after his return to England from his voyage, he ventured to submit a paper developing his theory of the origin of species. A year later, when his theory appeared in book form, as The Origin of Species, Darwin emerged as a famous and controversial figure.
From The Origin of Species
From Chapter 3. Struggle for Existence
We will now discuss in a little more detail the struggle for existence. Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult?at least I have found it so?than constantly to bear this conclusion in mind. Yet unless it be thoroughly engrained in the mind, the whole economy of nature, with every fact on distribution, rarity, abundance, extinction, and variation, will be dimly seen or quite misunderstood. We behold the face of nature bright with gladness, we often see superabundance of food; we do not see or we forget, that the birds which are idly singing round us mostly live on insects or seeds, and are thus constantly destroying life; or we forget how largely these songsters, or their eggs, or their nestlings, are destroyed by birds and beasts of prey; we do not always bear in mind, that, though food may be now superabundant, it is not so at all seasons of each recurring year.
[THE TERM, STRUGGLE FOR EXISTENCE, USED IN A LARGE SENSE]
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. 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 be dependent on the moisture. A plant which annually 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 farfetched sense be said to struggle with these trees, for, if too many of these parasites grow on the same tree, it languishes and dies. 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.
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1 154 0 / EVOLUTION
[GEOMETRICAL RATIO OF INCREASE]
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. 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 Malthus1 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.
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. 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. Linnaeus2 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.
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[COMPLEX RELATIONS OF ALL ANIMALS AND PLANTS TO EACH OTHER IN THE STRUGGLE FOR EXISTENCE]
Many cases are on record showing how complex and unexpected are the checks and relations between organic beings, which have to struggle together in the same country.
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Nearly all our orchidaceous plants absolutely require the visits of insects to remove their pollen-masses and thus to fertilise them. I find from experiments that humble-bees' are almost indispensable to the fertilisation of the hearts- ease (Viola tricolor), for other bees do not visit this flower. I have also found that the visits of bees are necessary for the fertilisation of some kinds of clover; for instance, 20 heads of Dutch clover (Trifolium repens) yielded 2,290 seeds, but 20 other heads protected from bees produced not one. Again, 100 heads
I. Thomas Robert Malthus (1 766-1834), British 2. Carl Linnaeus (1707?1778), Swedish natural- social theorist who argued that the population, ist who developed the binomial system?genus increasing geometrically, would grow beyond the plus species name?for naming plants and animals means of subsistence, which increased
