Alfred Russel Wallace: Existence

“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.”

Alfred Russel Wallace

"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.

Age , Success , Past

“That such a moth exists in Madagascar may be safely predicted”

Alfred Russel Wallace

"Creation by law". Quarterly Journal of Science 4: 470–488 (1867); The hawkmoth of Madagascar was later found and described in 1903, under the taxon name praedicta in reference to Wallace's quote.
Context: I have carefully measured the proboscis of a specimen of [Neococytius] cluentius from South America in the collection of the British Museum, and find it to be nine inches and a quarter long! One from tropical Africa ([Xanthopan] morganii) is seven inches and a half. A species having a proboscis two or three inches longer could reach the nectar in the largest flowers of Angræcum sesquipedale, whose nectaries vary in length from ten to fourteen inches. That such a moth exists in Madagascar may be safely predicted; and naturalists who visit that island should search for it with as much confidence as astronomers searched for the planet Neptune - and they will be equally successful!

“I thought of the long ages of the past, during which the successive generations of this little creature had run their course — year by year being born, and living and dying amid these dark and gloomy woods, with no intelligent eye to gaze upon their loveliness; to all appearance such a wanton waste of beauty. Such ideas excite a feeling of melancholy. It seems sad that on the one hand such exquisite creatures should live out their lives and exhibit their charms only in these wild inhospitable regions, doomed for ages yet to come to hopeless barbarism; while, on the other hand, should civilized man ever reach these distant lands, and bring moral, intellectual, and physical light into the recesses of these virgin forests, we may be sure that he will so disturb the nicely-balanced relations of organic and inorganic nature as to cause the disappearance, and finally the extinction, of these very beings whose wonderful structure and beauty he alone is fitted to appreciate and enjoy. This consideration must surely tell us that all living things were not made for man. Many of them have no relation to him. The cycle of their existence has gone on independently of his, and is disturbed or broken by every advance in man’s intellectual development; and their happiness and enjoyments, their loves and hates, their struggles for existence, their vigorous life and early death, would seem to be immediately related to their own well-being and perpetuation alone, limited only by the equal well-being and perpetuation of the numberless other organisms with which each is more or less intimately connected.”

Alfred Russel Wallace book The Malay Archipelago

The Malay Archipelago (1869)

Love , Life , Death , Hate

“Every species has come into existence coincident both in space and time with a pre-existing closely allied species.”

Alfred Russel Wallace

"On the Law which has Regulated the Introduction of New Species" (1855).

Time

“We permit absolute possession of the soil of our country, with no legal rights of existence on the soil to the vast majority who do not possess it. A great landholder may legally convert his whole property into a forest or a hunting-ground, and expel every human being who has hitherto lived upon it. In a thickly-populated country like England, where every acre has its owner and its occupier, this is a power of legally destroying his fellow-creatures; and that such a power should exist, and be exercised by individuals, in however small a degree, indicates that, as regards true social science, we are still in a state of barbarism.”

Alfred Russel Wallace book The Malay Archipelago

Last Words, addendum to later editions.
The Malay Archipelago (1869)

Exercises , Science , Country