“This progression, by minute steps, in various directions, but always checked and balanced by the necessary conditions, subject to which alone existence can be preserved, may, it is believed, be followed out so as to agree with all the phenomena presented by organized beings, their extinction and succession in past ages, and all the extraordinary modifications of form, instinct, and habits which they exhibit.”
"On the Tendency of Varieties to Depart Indefinitely From the Original Type" (1858).
Context: The powerful retractile talons of the falcon- and the cat-tribes have not been produced or increased by the volition of those animals; but among the different varieties which occurred in the earlier and less highly organized forms of these groups, those always survived longest which had the greatest facilities for seizing their prey. Neither did the giraffe acquire its long neck by desiring to reach the foliage of the more lofty shrubs, and constantly stretching its neck for the purpose, but because any varieties which occurred among its antitypes with a longer neck than usual at once secured a fresh range of pasture over the same ground as their shorter-necked companions, and on the first scarcity of food were thereby enabled to outlive them. [... ] We believe we have now shown that there is a tendency in nature to the continued progression of certain classes of varieties further and further from the original type - a progression to which there appears no reason to assign any definite limits - and that the same principle which produces this result in a state of nature will also explain why domestic varieties have a tendency to revert to the original type. This progression, by minute steps, in various directions, but always checked and balanced by the necessary conditions, subject to which alone existence can be preserved, may, it is believed, be followed out so as to agree with all the phenomena presented by organized beings, their extinction and succession in past ages, and all the extraordinary modifications of form, instinct, and habits which they exhibit.
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Alfred Russel Wallace 12
British naturalist, explorer, geographer, anthropologist an… 1823–1913Related quotes

Speech to the Anti-Socialist and Anti-Communist Union (17 February 1933), quoted in Martin Gilbert, Prophet of Truth: Winston S. Churchill, 1922–1939 (London: Minerva, 1990), p. 457
The 1930s

The Development Hypothesis (1852)
Context: The blindness of those who think it absurd to suppose that complex organic forms may have arisen by successive modifications out of simple ones becomes astonishing when we remember that complex organic forms are daily being thus produced. A tree differs from a seed immeasurably in every respect... Yet is the one changed in the course of a few years into the other: changed so gradually, that at no moment can it be said — Now the seed ceases to be, and the tree exists.

Kosmos (1932), Above is Beginning Quote of the Last Chapter: Relativity and Modern Theories of the Universe -->
Lawrence Kelso Frank (1948) Society as the Patient: Essays on Culture & Personality. p. 351; as cited in: Betsy Caton Goss (1991) Accounting quality and dispersion of financial analysts. p. 15

p, 125
Evolution and Ethics (1893)

"Are Shelters the Answer?", in The New York Times Magazine (26 November 1961), p. 125
1960s

On The Algebra of Logic (1885)
Context: Any character or proposition either concerns one subject, two subjects, or a plurality of subjects. For example, one particle has mass, two particles attract one another, a particle revolves about the line joining two others. A fact concerning two subjects is a dual character or relation; but a relation which is a mere combination of two independent facts concerning the two subjects may be called degenerate, just as two lines are called a degenerate conic. In like manner a plural character or conjoint relation is to be called degenerate if it is a mere compound of dual characters.
A sign is in a conjoint relation to the thing denoted and to the mind. If this triple relation is not of a degenerate species, the sign is related to its object only in consequence of a mental association, and depends upon a habit. Such signs are always abstract and general, because habits are general rules to which the organism has become subjected. They are, for the most part, conventional or arbitrary. They include all general words, the main body of speech, and any mode of conveying a judgment. For the sake of brevity I will call them tokens.