Darwin and Evolution

Sketch of a young DarwinCharles Darwin is famous for his part in articulating the theory of evolution by natural selection in 1858, which was followed by his publication of 'On the Origin of Species by means of Natural Selection’, published in 1859. Both still spark debate over 150 years later.

Darwin was interested in how and why species changed over time in different environments, generating the diversity of life. Encounters on the Galápagos Islands with marine iguanas, mockingbirds and giant tortoises encouraged him to think about transmutation, or change, leading to the origin of species. His early studies of barnacles perfected his understanding of anatomical detail, enabling him to study variation and change in more depth. He didn’t know about genes or DNA but knew there must be a mechanism by which characteristics passed from generation to generation. He asked many people including farmers, pigeon fanciers and gardeners, for data to test and strengthen his ideas. Darwin thought about his theory for over 20 years but may have been apprehensive about publishing it because of its wide-ranging implications.
 
A letter from Alfred Russel Wallace in 1858, sharing his own ideas about evolution, was the catalyst for Darwin to publish his work. Their joint papers were read at the Linnean Society of London on 1st July, 1858, but they did not have immediate impact. The Society’s Annual Report records that the year had not “… been marked by any of the striking discoveries which at once revolutionize, so to speak, the department of science on which they bear”. These ideas did revolutionize scientific thinking and continue to do so to this day.

Alfred Russel Wallace (1823–1913) was a British naturalist who conducted extensive research in the Amazon and then in the Malaysian Archipelago. Wallace corresponded with Darwin and in June 1858 sent him his paper “On the Tendency of Varieties to depart indefinitely from the Original Type”. This paper together with an extract from unpublished material from a letter by Darwin and a letter he wrote to Professor Asa Gray in Boston USA, was read at the Linnean Society of London on 1st July 1858—the first presentation on the theory of evolution. The Linnean Society of London. Alfred Russel Wallace. The Linnean Society of London. This photo of Darwin shows him seated with his young son William on his knee, around 1842, when they were living in Gower Street, London. Darwin, though devoted to his work, was very much a family man and William was the first of his ten children, three of whom sadly died in childhood. The Linnean Society of London As a student in Edinburgh Darwin was interested in invertebrate zoology. His now famous study of barnacles, or Cirripedia, was made between 1846–1854, in a break from working on his theory of evolution by natural selection. His barnacle study did aid his theory and helped him to finely hone his knowledge of scientific naming, or nomenclature. The Linnean Society of London. Darwin’s examination of the distribution of the world’s coral reefs was his first monograph, or in-depth scientific study. This map is taken from the resulting publication The Structure and Distribution of Coral Reefs (1842). In Darwin’s time there was great interest in how coral reefs and atolls were formed. Darwin theorised that the development of coral reefs were due to movement of the earth’s crust, either upwards or downwards, with the sun-seeking coral needing to remain near to the surface of the water. The Linnean Society of London.
This copy of a sketch of Darwin shows him seated as a young man. The original drawing is thought to be a preliminary sketch by George Richmond for his famous 1830s watercolour painting of Darwin after his return from the Beagle voyage. The Linnean Society of London. Darwin’s fame was captured in the inclusion of his portrait in the Literary and Scientific Portraits Club. In a letter to his friend and director of the Royal Botanic Gardens, Kew, J. D. Hooker, Darwin remarked 'if I really have as bad an expression, as my photograph gives me, how I can have one single friend is surprising’. The Linnean Society of London. This portrait of Charles Darwin painted by John Collier hangs in the meeting room at the Linnean Society of London. The Linnean Society of London Barnacles In Darwin's book The Voyage of the Beagle, Darwin remarked on the difference in the beak size of different species of finches even within this small group, suggesting that the beak may have been “modified” for different purposes. The Linnean Society of London.
This image of Darwin is a contact print produced from a negative of a photo taken by Herbert Rose Barraud. It is thought by some to possibly be the last image of Darwin taken before his death in 1882. The Linnean Society of London. Ernst Haeckel, a German biologist and promoter of Darwin’s work, included this image of Sapphirina darwinii in his book Kunstformen der Natur (1904). It is a type of copepod, or small aquatic crustacean, and is part of the largest group of metazoans, or multi-celled organisms, found in water. The Linnean Society of London. Darwin's signature Testudo elephantina, a species of giant tortoise found in the Indian Ocean. Darwin’s observations of giant tortoises also contributed to the development of his theory of evolution. Whilst on the Galápagos Islands he saw that some tortoises had shells that were dome-shaped, whilst the others had shallower saddle-shaped shells. The Linnean Society of London. This copy of a sketch of Darwin shows him seated as a young man. The original drawing is thought to be a preliminary sketch by George Richmond for his famous 1830s watercolour painting of Darwin after his return from the Beagle voyage. The Linnean Society of London.
Library Linnean Publications Shelf Linnean Strongroom Meeting Room Darwin’s theory of evolution by natural selection was shaped in part by his voyage on the Beagle. In South America he studied a new species of rhea (the lesser rhea, once known as Rhea darwinii), a flightless bird, which was competing for territory with the common rhea (Rhea americana). This became central to his ideas – that the fiercest struggles were between the closest rivals. The Linnean Society of London.


The Linnean Society of London

The Linnean Society of London is the world’s oldest active biological society. Founded in 1788, the Society takes its name from the Swedish naturalist Carl Linnaeus (1707–1778) whose botanical, zoological and library collections have been in its keeping since 1829. As it moves into its third century the Society continues to play a central role in the documentation of the world’s flora and fauna—as Linnaeus himself did—recognising the continuing importance of such work to biodiversity conservation.

For more information visit the Linnean Society of London website www.linnean.org