It's common knowledge that Darwin is considered the father of evolution, but even humans have been breeding animals (and probably themselves) selectively for specific traits for thousands of years. How much of the theory of evolution actually existed before Darwin caused big waves?
To add to the two previous answers:
Bernard-Germain-Etienne de Lacepède in "Histoire naturelle des poissons" (Natural History of Fishes) 1798 wrote the following:
Une espèce peut s'éteindre de deux manières. Elle peut périr toute entière, et dans un temps très-court, lorsqu'une catastrophe violente bouleverse la portion de la surface du globe sur laquelle elle vivoit, [...] Mais, indépendamment de ces grands coups que la Nature frappe rarement et avec éclat, une espèce disparoît par une longue suite de nuances insensibles et d'altérations successives.[...] Troisièmement, l'espèce peut subir un si grand nombre de modifications dans ses formes et dans ses qualités, que, sans rien perdre de son aptitude au mouvement vital, elle se trouve, par sa dernière conformation et par ses dernières propriétés, plus éloignée de son premier état que d'une espèce étrangère : elle est alors métamorphosée en une espèce nouvelle.
which translates roughly to the following [Disclaimer: own translation, hence poor quality]:
"A species can become extinct in two ways. It can die out entirely, and in a very short time, when a violent catastrophe shatters the portion of the earth's surface it lives on [...] But independantly to these big blows that Nature strike rarely and resoundingly, a species disappears by a long serie of imperceptible differences and successives alterations. [...] Thirdly, the species can undergo such a large number of modifications in its forms and qualities that, without losing its aptitude to the vital movement, it finds itself, in its last conformation and its last properties, further away from its first state than another species: it is then metamorphosed into a new species."
Erasmus Darwin was already named by @winwaed so I won't expand but here is an extract of his Zoonomia (1801):
As air and water are supplied to animals in sufficient profusion, the three great objects of desire, which have changed the forms of many animals by their exertions to gratify them, are those of lust, hunger, and security.
This prefigures quite obviously the notion of natural selection.
Jean-Baptiste Lamarck was also already quoted by @winwaed, but to expand on him: he expressed the idea that species were transforming through time for the first time in 1801 in its "Discours d'Ouverture du cours de Zoologie, donné dans le Museum d'Histoire Naturelle l'an 8 de la République" (litt.: "Opening speech of the Zoology course, given in the Natural History Museum in the year 8 of the Republic"). He thought in particular that species were transforming to adapt to their environment. He later expanded more on that in his books (in particular 'Philosophie zoologique' in 1809).
Johann Wolfgang von Goethe, more famously known as a poet, was also a naturalist, and a "transformist" (as pre-Darwinian evolutionist were often called, by opposition to "fixists"). here is what he wrote in "Story of My Botanical Studies" (1831) [extract found on his wikipedia page]:
The ever-changing display of plant forms, which I have followed for so many years, awakens increasingly within me the notion: The plant forms which surround us were not all created at some given point in time and then locked into the given form, they have been given... a felicitous mobility and plasticity that allows them to grow and adapt themselves to many different conditions in many different places.
One of the main tool in recognizing that two species evolved from the same ancester is the homology, and there is quite a string of researchers that led to the refinement of this concept, among them: Michel Adanson (1727-1806) established a classification of beings based on "the greatest number of similarities" and Etienne Geoffroy Saint-Hilaire (1772-1844) who not only formalized the concept of homology (under the name "analogy" at the time) but also thought that species changed according to their living conditions (according to the Encyclopedia britannica entry on him).
Some more pre-Charles Darwin discussions:
- Erasmus Darwin (Charles' grandfather): http://www.ucmp.berkeley.edu/history/Edarwin.html
- Jean-Batiste Lamarck: http://en.wikipedia.org/wiki/Lamarckism
- Robert Chambers "Vestiges of the Natural History of Creation" (heavily criticized at the time and with political undercurrents)
James Hutton also wrote on the topic and his ideas sound suspiciously Darwinian (it should be noted that Hutton also had his own farm and was aware of selective breeding). However, Hutton was noted for his obtuse writings (his geological ideas would have been ignored if it were not for John Playfair), and more importantly, his evolutionary writings were unpublished and only discovered in the 20th century.
The first known discussion concerning evolution are, to my knowledge, pre-Socratic philosophers. A more well known ancient publication evoking the idea may be De Rerum Natura, by Roman philosopher Lucretius.
This answers your title question, I don't have sufficient knowledge to satisfactorily address the question in the body of the text. It might be worth it to look into Maupertuis's work on "natural modifications", as he called them.
(Kirk, Geoffrey; Raven, John; Schofield, John (1984a). The Presocratic Philosophers: A Critical History with a Selection of Texts (3rd ed.). Chicago: The University of Chicago Press. pp. 100–321)
I remember reading something about it in Bertrand's Russell's "A History of Western Philosophy". Although it's a disputed work in its historical rigour, it does point out some predecessors to Darwin's theory of evolution.
There was evolution also in the animal kingdom. Living creatures arose from the moist element as it was evaporated by the sun. Man, like every other animal, was descended from fishes. He must be derived from animals of a different sort, because, owing to his long infancy, he could not have survived, originally, as he is now.
Another quaint one regarding Empedocles:
He knew that there is sex in plants, and he had a theory (some-what fantastic, it must be admitted) of evolution and the survival of the fittest. Originally, "countless tribes of mortal creatures were scattered abroad endowed with all manner of forms, a wonder to behold." There were heads without necks, arms without shoulders, eyes without foreheads, solitary limbs seeking for union. These things joined together as each might chance ; there were shambling creatures with countless hands, creatures with faces and breasts looking in different directions, creatures with the bodies of oxen and the faces of men, and others with the faces of oxen and the bodies of men. There were hermaphrodites combining the natures of men and women, but sterile. In the end, only certain forms survived.
Here's the full source of the text: https://archive.org/details/westernphilosoph035502mbp
Before the modern day scientists, there was the evolution concepts in the ancient cultures. For example consider the ancient vedic culture in India. Hinduism is the major religion in India, but it is only an extension of ancient Vedic culture which is widely known as Sanathana Dharma. Apart from religious rituals, Hinduism handles many more things.
In one of the oldest religion in the world, Hinduism there are some attempts to reconcile evolution theory to the avatars of god Vishu(one of the god among Hindu trinity) in the scriptures. There are lots of internet resources discussing the subject.
Monier Monier-Williams wrote "Indeed, the Hindus were ... Darwinians centuries before the birth of Darwin, and evolutionists centuries before the doctrine of evolution had been accepted by the Huxleys of our time, and before any word like evolution existed in any language of the world." J. B. S. Haldane suggested that Dashavatara gave a "rough idea" of vertebrate evolution: a fish, a tortoise, a boar, a man-lion, a dwarf and then four men (Kalki is not yet born). Nabinchandra Sen explains the Dashavatara with Darwin's evolution in his Raivatak. C. D. Deshmukh also remarked on the "striking" similarity between Darwin's theory and the Dashavatara.
Some modern interpreters sequence Vishnu's ten main avatars in a definitive order, from simple life-forms to more complex, and see the Dashavataras as a reflection, or a foreshadowing, of the the modern theory of evolution. Such an interpretation was first propounded by Theosophist Helena Blavatsky in her 1877 opus Isis Unveiled, in which she proposed the following ordering of the Dashavataras:
Matsya - fish, the first class of vertebrates; evolved in water
Kurma - amphibious (living in both water and land; but not to confuse with the vertebrate class amphibians)
Varaha - wild land animal (a form of Boar)
Narasimha - beings that are half-animal and half-human (indicative of emergence of human thoughts and intelligence in powerful wild nature)
Vamana - short, premature human beings
Parasurama - early humans living in forests and using weapons
Rama - humans living in community, beginning of civil society
Krishna - humans practicing animal husbandry, politically advanced societies
Buddha ( I doubt Buddha is not an accepted avatar of Vishnu among Hindus, directly quoted from wiki) - humans finding enlightenment
Kalki - advanced humans with great powers of destruction.
As the Hindu puranas were written thousands of years ago and written by unknown writers, it may not be possible to say that it actually existed as a theory in ancient days. I assume as vedic scriptures are sources of many hidden facts, interested people can have a good research on the same. Anyway Dasavatar(10 avatars) have similarity to the theory of evolution proposed by Darvin and it could be the first among such theories if proper proofs or studies were there on these scriptures and texts.
This is adding to previous answers, but the philosopher Immanuel Kant is another interesting example. In the 1780-1790s, he appears to have had rather well-developed ideas about evolutionary change, a common origin of life, that also included humans:
The agreement of so many genera of animals in a certain common schema, which appears to be fundamental not only in the structure of their bones but also in the disposition of their remaining parts,—so that with an admirable simplicity of original outline, a great variety of species has been produced by the shortening of one member and the lengthening of another, the involution of this part and the evolution of that,—allows a ray of hope, however faint, to penetrate into our minds, that here something may be accomplished by the aid of the principle of the mechanism of nature (without which there can be no natural science in general). This analogy of forms, which with all their differences seem to have been produced according to a common original type, strengthens our suspicions of an actual relationship between them in their production from a common parent, through the gradual approximation of one animal-genus to another—from those in which the principle of purposes seems to be best authenticated, i.e. from man, down to the polype, and again from this down to mosses and lichens, and finally to the lowest stage of nature noticeable by us, viz. to crude matter. And so the whole Technic of nature, which is so incomprehensible to us in organised beings that we believe ourselves compelled to think a different principle for it, seems to be derived from matter and its powers according to mechanical laws (like those by which it works in the formation of crystals).
(from: Kant. 1790. Critique of Judgment, MacMillian 1914 (translated by Bernard), https://www.gutenberg.org/ebooks/48433)
Hat-tip to this answer at Philosophy-SE for finding the quote.
It's important to distinguish evolution of organisms, i.e. change of their characters over generational time, and natural selection. Darwin's greatest achievement was the development of the idea of natural selection in great detail, along with providing a great deal of evidence for its action. (Alfred Russel Wallace developed a version of the idea of natural selection independently, but only after Darwin had already worked out a more sophisticated, but then unpublished, version.) In contemporary evolutionary theory, there are multiple mechanisms that play a role in explaining evolutionary change, including random genetic drift.
Lucretius (c. 0 CE) claimed only to be reporting the views of Epicurus (c. 300 BCE) in Lucretius's book De Rerum Natura (On the Nature of Things). We have Epicurus's work only in fragmentary form, so it's not clear how much Lucretius has added to Epicurus's philosophy.
One idea that people think of as a precursor of "evolution" discussed in Epicurean philosophy appears to come originally from Empedocles (c. 460 BCE). It's the idea that at one time, there were animals with body parts put together in random forms. Only those animals with body parts that functioned well together survived. Lucretius presents this idea in Book 5, around lines 835-920 (e.g. pp. 182-184 in Esolen's translation of De Rerum Natura). (See also The Epicurus Reader, by Inwood and Gerson, p. 97.) Notice that this filtering of animals happens only once. The role that natural selection plays in evolution, according to Darwin, requires that traits be heritable, and that natural selection gradually shape them over time. (EDIT: My first version said that Lucretius "critiqued" Empedocles' proposal. Upon more careful reading, it appears that Lucretius endorsed the proposal, but objected to the view that there were certain specific animals such as centaurs.)
At lines 852-874, Lucretius discusses more subtle processes that are reminiscent of natural selection, saying, among other things (p. 183 in Esolen's translation):
And many kinds of creatures must have died,
Unable to plant out new sprouts of life.
For whatever you see that lives and breathes and thrives
Has been, from the very beginning, guarded, saved
By it trickery or its swiftness or brute strength.
That idea does sound a lot like natural selection, but gradual modification of inherited traits doesn't seem to be a part of it. Thus, even if the concept that Lucretius (and probably Epicurus) discussed should be considered a concept of natural selection, there's no reason to think that they had in mind evolution by natural selection, in the sense of change over a long period of time. Like Empedocles, Lucretius seems to have been talking about a filtering process that takes place once (see lines 835ff), and then never again, for any given set of species. Note that it's also not clear that Lucretius had in mind filtering of organisms within species. It's plausible that he was talking about some species failing to survive. If there is no gradual modification of heritable traits, much of what Darwinian natural selection involves is missing.
(BTW, there are many good translations of De Rerum Natura, which consists of thousands of lines of philosophical poetry in Latin. Esolen's is my favorite poetic translation. My favorite prose translation is by Martin Ferguson Smith.)