Darwinism
Ricardo Cueva Fernández
The term “Darwinism” seems closely linked to that of “evolution” and, indeed, is often used as its synonym. “Evolution” is a word with many connotations, but the main ones are usually linked to the concepts of change and improvement. This is how it was understood by 18th-century thinkers, scientists and naturalists, who were the first to begin using it in a sense similar to its current one. Indeed, it was Jean Baptiste Pierre Antoine de Monet, Chevalier de Lamarck (1744–1829), after the Comte de Buffon, who was the author who exerted the greatest influence on what is commonly referred to as the “transformist” school (Solís & Sellés, 2013, p. 910). This French Enlightenment thinker, whose life largely ran parallel to the French Revolutionary period and its subsequent Bonapartist drift, wrote a famous volume, Philosophie Zoologique (1809/2017), in which he set out the main points of his theory on the origin of species, anticipating the problem that C. Darwin would later attempt to address in his most celebrated work.
Lamarck understood that living beings had arisen from certain processes occurring in inert matter (through “spontaneous” or “direct” generation, 2017, p. 356), and that they were mutating, in a long and slow chain, due to certain habits that emerged in response to new situations (p. 96). For the eminent Frenchman, additionally, those modifications were passed on to descendants and, in this succession—which consisted chiefly of individuals—there were no extinctions; rather, in truth, some species were replaced by others in the aforementioned chain, and the variations observed amongst them were due to the differing rates at which individuals underwent mutation, starting with “infusoria” (p. 130). Adaptation arose from emerging needs (p. 199). The most complex and perfect of these living beings, in any case, was, for Lamarck, the human being itself, as it possessed intelligence and thus secured more favourable conditions for its existence (pp. 132 and 575).
This theory, despite the opposition it provoked due to its implicit materialism (Ruse, 1979/1983, p. 26), had numerous followers, but faced considerable problems of verification. Thus, first and foremost, the discovery of animals such as those present in archaic periods (Larson, 2004, p. 42) and the discontinuity of the fossil record (Bowler, 1992, p. 209) were highlighted. In this regard, palaeontology seemed to suggest that certain insights into the origin of life and its development might be found in the strata where these fossil remains were found, namely those analysed by geology. Charles Lyell (1797–1875) and George Cuvier (1769–1832) were two of the scientists who sought to trace the superposition, the movement of seas and oceans, and the displacement of tectonic plates. The latter led a school of thought that pointed to the existence of various types of catastrophes, such as earthquakes and floods, which could cause some species to appear and others to survive (Larson, op. cit., p. 43).
However, he had little influence on a theory that would soon be seen as promising, namely that of natural selection, whereas, on the contrary, Ch. Lyell, Scottish in origin and a contemporary of Darwin, would prove to be a catalyst. This geologist understood that there were no catastrophes or sudden changes (Lyell, 1882, pp. 436–8) but that, in reality, what occurred were events of a recurring and moderate nature: landslides or erosion were slow and geographically limited processes (pp. 563–4). Geological phenomena of the past were not substantially different from those of the present; and species had not arisen by spontaneous generation, and, furthermore, were stable (pp. 2–35). Some might disappear, but they did so with a certain regularity governed by natural laws (pp. 179–184).
It was Darwin, in fact, who took up Lyell’s idea of “deep time” (Sharukán, 2003, p. 69), and this enabled him to explain phenomena that occurred in the past using causes operating in the present (Darwin, 1859/2008, pp. 166 and 623), thereby embracing the gradualism that would characterise his theory. Indeed, if we read his Origin of Species carefully, we shall observe not only the same interest that the Scotsman had in finding the natural causes of transformations on Earth, but also his clear rejection, in line with this, of “catastrophist” proposals such as that of Cuvier, but also followed by others of his time, such as Leopold von Buch or William Buckland (Bowler, 1992, pp. 172 and 173). Darwin, seeking continuity in the fossil record, took as his reference a geological age of the planet far greater than that which had hitherto been assumed; he paid absolutely no heed to the prevailing “creationist” view of the time; and he drew various conclusions from the very behaviour that man had exhibited towards other living beings, such as the plants and animals he cultivated and reared.
This led him to conclude that species could vary over short periods of time, thanks to the mechanism he termed “natural selection”, by analogy with the domestic selection that humans had applied to animals (pp. 607–8). To this end, he took into account the relationship between the organic individual and the environment, and defined the aforementioned mechanism as that which gave rise to the struggle for existence within a specific context in which there were limited resources for survival and, therefore, for reproduction: his contemporary A. R. Wallace would also reach these conclusions, in parallel and drawing on the same sources (H. Spencer and T. Malthus), although he did not use the same term for the discovery (Ruse, 1979/1983, pp. 198–203). Species could indeed become extinct (Darwin, 1859, p. 141), contrary to what those who subscribed to the model of providential design had thought (Larson, 2004, p. 122), and even contrary to what Lamarck had tended to defend.
This dependence on the environment could be overcome, for example, through migration (p. 503), but the limit to diversification, and thus to escaping extinction, would always be determined by resources and the possibility of mating and reproduction (impossible outside the concept, albeit relative according to Darwin, of “species”), which would thus circumscribe the traits transmitted (Darwin, 1859, pp. 163–7). It was precisely this latter issue—how the transmission of inherited traits actually took place—that gave Darwin such a headache; he was only able to offer a tentative solution through an improvised hypothesis on “gemmules” and “pangenesis” in The Descent of Man, published in 1871 (Larson, 2004, p. 159). But soon new discoveries would help to complete the British naturalist’s findings.
The most prominent of these was G. Mendel (1822–1844). Having published his work in Versuche über Pflantzenhybriden (Experiments on Plant Hybridisation, 1866; see Solís & Sellés, 2013, p. 957), and although it is assumed that Darwin never actually read it (Ruse, 2008, p. 100) or, at best, that it did not catch his attention (Sharukán, 2003, p. 287), the article described an experiment with varieties of the plant Pisum sativum, which would imply the confirmation of a mechanism enabling, through certain units—later termed genes—the transmission of traits to offspring. August Weissman (Larson, pp. 160–61) and Hugo De Vries or Carl Correns (Larson, 200, p. 203) would later align with this line of research, in contrast to the still-persistent Lamarckian theories (Larson, 2004, p. 165). It was in the 1930s and 1940s that the evolutionary synthesis emerged, leading a group of scientists with extensive knowledge in their respective fields (Dieguez, 2012, p. 51) to gather highly convincing evidence that confirmed the path initiated by the author of On the Origin of Species.
In general, the entire body of work produced by the group signified the complete emancipation of biology from other fields of knowledge, particularly physics, with which it had initially been compared. It also meant definitively coining the term “evolution” to identify the project initiated by Darwin, even though he did not usually use it in his work, preferring instead the term “theory of descent with modification” (1859, p. 602). Prior to this, the absence of fossils indicating a missing link between humans and apes made it difficult for the general public to accept the bulk of Darwin’s ideas (Larson, 2004, p. 179). Modern molecular biology of recent decades has likewise served to highlight the universality of the genetic code (Dieguez, 2012, p. 50), which brings to light the common ancestry that many still claimed not to perceive. This had been pointed out very early on by discoveries in archaeology and anthropology between the late 19th and early 20th centuries (Larson, 2004, pp. 182–192), two disciplines sometimes overlooked in this whole discussion.
However, it is not entirely clear to the author of this article whether the general public has accepted the main tenets of the Darwinian project, despite all its milestones. After all, we should not overlook the fact that these entail very significant changes. The theory of evolution, of which natural selection forms a part, although not the only component (Mayr, 1991, pp. 48–50), implies that we must perceive the relationship between humankind and nature in a manner very different from the traditional view throughout human history (see Environmental history).
Firstly, because it emphasises the importance of the “environment”. The notion that we cannot survive as a species if we attempt to exceed the limits set by resources—and, consequently, the interrelationship we maintain with our surroundings—is central to understanding the ecological challenge we face. But it is not just a matter of our own survival, but also that of other living beings with whom we have co-evolved throughout our history. E. O. Wilson’s (1929–2021) proposal on biodiversity and his Half Earth (2017) is, quite simply, the recognition of that connection and of the need for variation and diversification for life to be sustained, in accordance with Darwin’s principle of divergence: “the more the descendants of any given species differ in structure, constitution and habits, the more capable they will be of occupying many and more diverse positions in the economy of nature” (1859, p. 179).
Secondly, the premises of an “evolution” that does not necessarily imply progress or an end demand the adoption of a far broader sense of responsibility than that currently assumed by the political communities across the globe. And thirdly, and finally, the supposed superiority of human beings over all other living creatures on earth is clearly untenable, for the very reasons Darwin pointed out in his principal work, when he emphasised a common origin for all species and asserted that the improvement of each being through natural selection operated only “in relation to its particular organic and inorganic conditions of life” (1859, p. 195), and did not stem from a supposed hierarchical position within the whole (see Anthropocentrism, Biocentrism and Ecocentrism).
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