In July, 1858, the Linnean Society gathered at its new headquarters in London to hear two papers by Charles Darwin and Alfred Russel Wallace in which they jointed announced a theory of evolution by natural selection. One of the many common misconceptions about biological evolution is that this was an idea first proposed by Charles Darwin. In reality, a number of scientists and natural philosophers had already written about this concept prior to Darwin.
Erasmus Darwin:
Erasmus Darwin (1731-1802), the grandfather of Charles Darwin, was an English physician, poet, inventor, and natural philosopher. He attended St. John’s College, Cambridge and received his medical education at the University of Edinburgh Medical School. He spent fifty years as a successful physician in the Midlands (this is an area of central England that roughly corresponds to the early medieval Kingdom of Mercia.)
Physically, Erasmus Darwin (shown above) might be described as a big man: he stopped weighing himself when he reached 336 pounds. He was married twice and had 14 children.
During a seven-year time period, Darwin translated the works of the Swedish botanist Carolus Linnaeus from Latin into English. In doing this, Darwin coined many of the English names for plants that are still being used today.
His most important scientific work was Zoonomia, which incorporated some early ideas regarding evolution. Like Linnaeus and other natural philosophers, he noted the great similarity in structure among warm-blooded animals and the changes they went through. He wrote:
“Would it be too bold to imagine, that in the great length of time, since the earth began to exist, perhaps millions of ages before the commencement of the history of mankind, would it be too bold to imagine, that all warm-blooded animals have arisen from one living filament, which THE GREAT FIRST CAUSE embued with animality, with the power of acquiring new parts, attended with new propensities, directed by irritations, sensations, volitions, and associations; and thus possessing the faculty of continuing to improve by its own inherent activity, and of delivering down those improvements by generation to its posterity, world without end!”
He went further by writing:
“Shall we then say that the vegetable living filament was originally different from that of each tribe of animals above described? And that the productive living filament of each of those tribes was different originally from the other? Or, as the earth and ocean were probably peopled with vegetable productions long before the existence of animals...shall we conjecture that one and the same kind of living filament is and has been the cause of all organic life?”
In 1803, his final long poem,
The Temple of Nature, was published posthumously. This is not only considered his best poetic work, but it centers on his concept of evolution.
Organic life beneath the shoreless waves
Was born and nurs'd in ocean's pearly caves;
First forms minute, unseen by spheric glass,
Move on the mud, or pierce the watery mass;
These, as successive generations bloom,
New powers acquire and larger limbs assume;
Whence countless groups of vegetation spring,
And breathing realms of fin and feet and wing.
Darwin also speculated on the cosmological theories of the Big Bang and the Big Crunch in his poetry.
Darwin was also a life-long friend with the American scientist Benjamin Franklin.
Jean-Baptiste Lamarck:
In 1800, Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1744-1829) declared that the fixity of species was an illusion. He proposed that species had not all been created in their current form at the dawn of time. New species, he postulated, had formed through spontaneous generation. As species evolved they achieved higher and higher levels of complexity. Carl Zimmer, in his book Evolution: The Triumph of an Idea, describes it this way:
“The continual emergence of species and their ongoing transformation created the Great Chain of Being: lower members of the chain had simply started their upward journey later than high members.”
According to Larmarck, as a species adapted to its environment, it passed these adaptations on to its offspring. With regard to humans, Zimmer reports:
“Lamarck suggested that humans might have descended from apes that left the trees, stood upright, and walked out onto the plains. The very effort of trying to walk on two legs would have gradually changed their bodies to our own posture.”
In 1809, Lamarck outlined his theory of evolution in
Philosophie zoologique ou exposition des considérations relatives à l'histoire naturelle des animaux (Zoological Philosophy: Exposition with Regard to the Natural History of Animals). His proposed theory of evolution is now known as Lamarckism. Lamarck proposed that species could acquire new characteristics from influences in their environment:
"as new modifications will necessarily continue to operate, however slowly, not only will there continually be found new species, new genera, and new orders, but each species will vary in some part of its structure and form ... individuals which from special causes are transported into very different situations from those where the others occur, and then constantly submitted to other influences - the former, I say, assume new forms, and then they constitute a new species."
In other words, an organism can pass on characteristics that it had acquired to its offspring.
Lamarck is shown above.
Robert Edmond Grant:
Like Erasmus Darwin, Robert Edmond Grant (1793-1874) was educated at Edinburgh University and became a physician. In his doctoral dissertation, Grant cited Erasmus Darwin’s Zoonomia. In the early nineteenth century he became one of the foremost biologists at Edinburgh. He later became the first Professor of Comparative Anatomy at University College London.
Grant travelled widely and visited universities throughout Europe. During his travels he met Étienne Geoffroy Saint-Hilaire, the French zoologist who espoused a view of evolution similar to that of Lamarck.
With an evolutionary frame work, Grant studied sponges and sea pens because he thought they lay at the root of the animal kingdom. From forms like them, he reasoned, all other animals might have descended. Grant, like most of today’s scientists, felt the scientific laws affected all organisms, including humans. Following Geoffroy’s concept of evolution, Grant felt that life was arranged into a chain which went from simple to complex.
In 1826, Grant went public with his ideas about evolution: he had observed a progressive, natural succession of fossil animals. He proposed a common origin for plants and animals. Like Lamarck, Grant felt that external circumstances influenced the forms of plants and animals.
In 1826, Charles Darwin started his second year of medical studies at Edinburgh University and became one of Grant’s students. Grant, an admirer of Erasmus Darwin, became Charles Darwin’s mentor. Grant introduced Darwin to the ideas of evolution which had been put forth by Erasmus Darwin, Larmarck, and Geoffroy.
Robert Grant is shown above.
Patrick Matthew:
Perhaps the least well-known of the early evolutionists is Patrick Matthew (1790-1874) who published the principle of natural selection as a mechanism in evolution in 1831. This was 27 years before Darwin published his ideas on natural selection. Matthew, a landowner and fruit farmer in Scotland, did not develop or publicize his ideas.
Robert Chambers:
In 1844, Robert Chambers (1802-1871), a publisher and geologist in Edinburgh, published Vestiges of the Natural History of Creation anonymously. Written while he was recovering from a psychiatric illness, the book brought together various ideas of evolution with the transmutation of species. The book was well received and became an international best seller. This book seems to have prepared the general public for Charles Darwin’s ideas about evolution and natural selection.
Robert Chambers is shown above.