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Evolution

Evolution As A Theory Of Species Change, Charles Darwin And Descent With Modification By Means Of Natural Selection



Although it can encompass cosmic and cultural change, evolution is a term usually associated with the modern scientific theory of species change and is most closely associated with the work of Charles Darwin (1809–1882) and, to a lesser extent, Alfred Russel Wallace (1823–1913). Darwin himself did not refer to his specific theory as "evolution" but instead used the phrase "descent with modification." Only the very last word of his famous work laying out the argument for his theory, On the Origin of Species, which appeared in 1859, was "evolved." The term gained widespread currency especially in the English language and came to be virtually synonymous with Darwin and Darwinism because of its use by contemporaries like the social theorist Herbert Spencer (1820–1903) and by the numerous commentators, advocates, and translators, such as Thomas Henry Huxley (1825–1895) and Ernst Haeckel (1834–1919), who were carrying meanings into the theory of species change from areas of biology concerned with developmental processes like embryology.



Before then, the term evolution had been used in a number of contexts. Stemming from the Latin verb evolvere, the term generally refers to an unrolling or unfolding. The substantive form evolutio refers to the unrolling of a scroll. Implied in these meanings is the fact that something is there to unfold, develop, or unroll. Its scientific use was first noted in mathematics in the sixteenth century, but it was soon applied to the development or unfolding of ideas or principles. In the seventeenth century the term began to take on a biological cast when it was first used by an anonymous English reviewer to characterize the embryological theories set forth by Jan Swammerdam (1637–1680). A preformationist, Swammerdam postulated a theory of insect development that relied on preexisting or preformed parts that expanded and grew in the embryonic larva. The semen of the male was required in this process, but only as a stimulus to realize the development of the adult form already encased in the semen of the female. The term evolution was thus coined initially to describe a developmental or embryological process of unfolding resulting in the reproduction of an adult form. Its application to the process of species change took place gradually in fits and starts over the next 150 years or so by a broad range of thinkers who increasingly carried over meanings of developmental or embryological unfolding in reproduction to theories of species change within historical, temporal, or geographical frame of references.

The extent to which the German Naturphilosophen ("nature philosophers") or German Romantic thinkers like Friedrich Wilhelm Joseph von Schelling (1775–1854) may have held evolutionary theories and the extent to which such views of dynamische Evolution ("dynamic evolution") shaped or even resembled subsequent evolutionary theories leading eventually to Darwinian evolution is the subject of lively discussion and controversy among historians of evolution of the eighteenth and early nineteenth centuries. The received view of the history of evolutionary thought does not usually locate the origins of Darwinian evolution in the German philosophical context, or in movements like Romanticism, but has instead located its intellectual origins in the context of Enlightenment views that included belief in progress, in theological movements like natural theology, and in the shifting views and practices of traditional natural history that led to reforms in taxonomic practices and in emerging related "sciences" like geology. Its social origins are generally linked to late-eighteenth-century economic theories that articulated laissez-faire policies, to the rise of industrial capitalist societies and states, and to the increasing linkage between natural history (and indeed science as whole) to colonialism and to imperialist ambitions, especially in Great Britain. In the received view, the history of evolution long predates Darwinian developments, though Darwin and his theory are given exceptional emphasis.

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