Evolutionary Thought Pre-Darwin pt. 2

A few weeks ago I wrote an article focused on evolutionary thought in the Ancient world, which was designed to be a two-part blog entry.  Within that article I wanted to start explaining how there has been a long tradition of evolutionary thought.  In part 2 of this series I want to explain the type of intellectual environment that was developing in the centuries leading up to Darwin and Wallace’s famous break through.

THE CHRISTIAN WORLD

After the collapse of the Roman Empire, Christian philosophers easily adopted teleological thought.  Throughout the Middle Ages some Christian thinkers knew of the idea of natural selection but dismissed it in favour of teleology (Kaye, 2006).  Philosophers like Thomas Aquinas (1225-1274 C.E.) believed that all organisms had been created in their perfect state and remained in that state, therefore, not changing at all over time (Gilson, 2009).  Despite the fact that there were a few ‘radical’ individuals throughout these centuries who would not just believe in a teleological view of nature simply because of the authoritative sources who purported its ‘Truth’, these views would not be challenged in any significant way until the late 18th century.

ENLIGHTENMENT THOUGHT

During the Enlightenment the European scientific scene began openly discussing the issue of the structure and history of life.  Throughout the late 18th century and the first half of the 19th century European scientists of various academic backgrounds began considering evolutionary theories.  Some of the problems for these ‘evolutionists’ became understanding the aqueous origin of the terrestrial globe, the decrease of the sea level, the emergence of land and the adaptation of marine life to surface and atmospheric conditions (Corsi, 2005).  The most common theory to explain evolution was the theory of climates and their influence on all living forms.  Bernard Germain Etienne da la Ville (1756-1825 C.E.) was a major proponent of climatic theories and frequently made analogies between ‘domesticated’ and ‘wild’ animals and how the ‘climate’ could modify organisms over time (Corsi, 2005).  Jean-Baptiste Lamarck (1744-1829 C.E.) and his followers offered a competing perspective, which proposed an explanation for biological change over time that operated through the heritability of acquired characteristics (Moore, 1981).  Lamarck believed that organisms adapt to their environment and that any traits that an organism acquired throughout its lifetime could be passed onto its offspring, therefore leading to increased perfection and complexity in organisms (Moore, 1981).  In Britain Erasmus Darwin (1731-1802 C.E.) had independently come to a similar conclusion in his most influential work Zoonomia in which he proposed the theory of the succession of life forms through successive adaptation (Corsi, 2005).

These early evolutionary theories fell out of favour with many prominent European naturalists shortly after they were first proposed.  Some of the most vocally resistant naturalists of Lamarckianism and climate-based theories were Charles Lyell (1797-1875), Robert Chambers (1802-1871), Richard Owen (1804-1892) and George Cuvier (1769-1832) (Moore, 1981; Appel, 1987).  Charles Lyell was a British geologist, not a biologist.  However, his revolutionary ideas about uniformitarianism had given many biologists an alternative way to understand natural history without resorting to theories whose explanatory power relied on the biblical flood (Anderson, 2007).  As a result Lyell was immersed in many evolutionary debates while writing Principles of Geology.  He commended Lamarck for being ‘courageous’ and ‘logical’ enough to understand that humans must have evolved from an ‘Ourang-Outang’, but he was also clear that he believed Lamarck had not discovered the mechanism of evolution (Lyell, 1881).  Robert Chambers, although first receptive to Lamarck’s ideas, later became critical of them.  He maintained that species had evolved through the indirect and heritable influence of the environment, but believed that organisms could only pass on characteristics acquired during the embryonic stage of life (Moore, 1981).  Richard Owen and George Cuvier were also resistant to Lamarckianism, and instead proposed an ‘organizing energy’ that directed the growth of tissues and determined the lifespan of an individual.  They were both vehemently opposed to Lamarck’s incorporation of transmutation (Moore; 1981; Appel, 1987).

However, Charles Darwin and Alfred Russel Wallace (1823-1913) each ‘re-discovered’ the theory of natural selection independently before 1859.  Charles Darwin had been working on the theory for over two decades before Charles Lyell, Thomas Huxley (1825-1895), Joseph Hooker (1814-1879) and other accomplished English naturalists convinced him that he needed to publish his work (Keynes, 1997; McCalman, 2009).  Darwin had been hesitant to publish his ideas due to the unstable and turbulent socio-political environment within Britain throughout the 1840s and 1850s, and also feared disrupting the personal dynamics of his family life (McCalman, 2009).  He started writing his masterwork on the theory of natural selection in 1856, but only two years later; Alfred Russel Wallace sent Darwin a letter, which revealed that Wallace had independently formulated his own theory of natural selection (Keynes, 1997).  Darwin was shattered and admitted to Charles Lyell that he had ‘never saw a more striking coincidence’ (Keynes, 1997: 470).  In 1858, the Linnean Society of London acknowledged both Darwin and Wallace as the proponents of this hypothesis, and thought it fair if Lyell and Hooker both presented on behalf of Wallace and Darwin at the next meeting of the Linnean Society to introduce the world to the theory of natural selection (Kutschera, 2003).

It was a long road to Darwin but that does not take away from the enormous impact the theory of evolution by natural selection has made.  Whether historians and scientists have taken the view that Darwin was a re-discoverer or co-discoverer of the theory of natural selection, they have always been intrigued as to how a young Englishman from Kent independently formulated one of the most important scientific theories in human history.

 

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About Cadell Last
I am a science educator, freelance science writer, and founder of The Advanced Apes based in Toronto, Ontario. In the past my academic research focused on the evolution, ecology, and behaviour of non-human primates (i.e., chimpanzees, gorillas, ring-tailed lemurs). Currently, my official blog, The Ratchet, can be found via The Advanced Apes and Svbtle. I enjoy exploring recent research in human evolutionary sciences, as well as biology, ecology, astronomy, physics, and computer science. My work has been featured in Scientific American, American Humanist, Richard Dawkins Foundation for Reason and Science, and Jane Goodall Institute of Canada. I am also exploring science popularization in new mediums in collaboration with PBS Digital Studios with an animated YouTube channel. You can contact me on Twitter (@cadelllast) or via email: cadell.last@gmail.com

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