2. THE IDEA OF EVOLUTION
From the Greeks to Darwin

Although the idea of evolution is today most closely associated with Charles Darwin than anyone else, he was not the first person to come up with the idea, nor even—as is often claimed—the first person to provide it with a trully rational (scientific?) basis. This lecture surveys the development of the idea of evolution from ancient times to the eve of the publication of Darwin's most famous book on the subject, The Origin of Species in 1859.

Evolution Among the Greeks

Though the word 'evolution' did not seem to have been used in a biological context until 1670,1 the idea of biological evolution, in the sense we now use it to describe the process by which new species are formed, is very old. It was a common conception among many ancient peoples that, e.g., damp earth spontaneously gave rise to frogs, rotting meat to maggots, and so on. Inherent in this conception of 'spontaneous generation' is the idea of evolution, that new life forms arise out of something else.2

The idea of evolution, however, was particularly rife among the Greek philosophers of Melitus. Thales (c. 624-545 BC), Anaximander (611-546 BC), Anaxagoras (c. 534-462 BC), and Empedocles (c. 490-440 BC) would all sign their names to the idea that species have changed over time. As Matthew Arnold rightly reminded his friend John Judd in 1871. "I cannot understand why you scientific people make such a fuss about Darwin. Why, it's all in Lucretius!"3

The Idea of the Species in a Christianzed Europe

The Greek idea of species change, however, were forgotten with the Christianization of Europe beginning in the 1st Cent AD. The biblical idea of creation early led most European thinkers to conceive of the species as fixed and immutable. A secondary idea (flowing from this though bit not logically necessarily so) is that no species have been lost or created since the time of their first creation. Early European naturalists were awed by the diversity and wonder of what they found in nature, and attributed such wonder to the wisdom of the God who created them, as narrated in the first chapters of the Bible. Not surprising, they understood their research as an act of worship, and the complexity of nature as proof that there was a God. Using a pletora of biological examples, William Paley (1743-1805), Archdeacon of Carlisle, on the logic that if one found a watch out in the field the inevitable inference must be that there must have been a watchmaker, so the amazing adaptations of nature to their environment point to purpose and design, from which we must infer that there is a Designer.

John Ray

The vast diversity of natural adaptations found in nature led them also to observe that not all creatures were created in equal complexities. Everyone knew, of course, that the earthworm was a 'simpler' creature than, say, a bird with its two wings, which seemed 'simpler' than a horse with its four legs, and so on. Along these lines of increasing degree of complexity or 'perfection' the early naturalists classified the plants and animals they studied into a hierachy of beings. Aristotle had, in fact, already begun to classify the plants and animals he knew under such a scheme. It was left to an English clergyman and nature lover, John Ray (1627-1705) to lay the foundation that would, though he did not then know it, eventually open the door to an evolutionary mode of thinking about nature. Brought up with a keen interest in botany by a herbalist mother, Ray travelled widely to add ever more species to his collection. Ray quickly recognized that any system of classification based on a single character can only be misleading, since there is no way to determine if one had picked the single essential character that distinguished one species from another. Using as many different characters as possible Ray arranged numerous species, first, of plants into groups according to the structures of their leaves, flowers and fruits. He did the same with animals, becoming the first to recognize, e.g., that bats were mammals, not birds, that some animals respire by means of lungs, others with gills. He was also the first person to define the species, which he understood as a group of organisms capable of interbreeding (a concept that remains little changed to this day). Of his contribution, Robert Huxley says, "In his 77 years, Ray has moved the study of the living world on from mysticism and fable and set it on a firm scientific basis."4 Ray's contribution to the advance of the biological sciences, however, was not motivated by mere curiosity—though that was necessary— but by a desire to understand clearly the works of God. The Wisdom of God, which he published in 1691 and brought together his observations of nature and a number of his sermons, illustrates this clearly.

The Challenge of Fossils

But John Ray was already being challenged with a serious decision. It had to do with—what to do with—fossils. Fossils have been known since antiquities. In the East they were called 'dragon-bones,' in the West glossopetrae or 'tonguestones.' In both they were thought to possess great medicinal value, their origin and nature a matter of myths and confusion. Some felt that they were merely rock or mineral deposits that happened to be so-shaped by some mysterious 'vis plastica.' Others thought that their resemblances to living things were too uncanny to be accidental. Yet others argued that they were the remains of real animals and plants laid down during Noah's Flood. The primary challenge presented by the fossils for those who took them seriously may be summed at this point in time in two questions: Are fossils the remains of once living things? If so, how did fossils of marine creatures like sea shells come to be deposited on mountain tops?

John Ray was himself one of the earliest persons to take the study of fossils seriously. He had met Steno (see below) and agreed with him that they were the remains of once living creatures. But did not that mean that some species created by God in the beginning had since become extinct? Would God allow such a thing? Ray's response was to suggest that living representatives of the fossils may yet be found in regions of the earth yet to be explored.5 Thus did Ray take to his grave the belief, slightly perturbed, in the constancy and fixity of the species.

Robert Hooke

If John Ray was prepared to ponder in private, Robert Hooke was quite prepared to lecture his speculations and still unconfirmed observations. Hooke (1635-1703) was a younger contemporary of John Ray, who made a name for himself as the first professional scientist when, on 25 March 1662 he was charged by the Royal Society of London to present a microscopical demonstration at each of the Society's meeting. In 1665 Hooke published Micrographa, a large volume of micrographs, images of objects seen under the microscope. Readers saw for the first time the glorious beauty of the ant, lice, flea, the cells of cork and the compound eyes of flies up close. It was the equivalent of the modern "coffee table book" (and it is still in print! 6).

Like Steno, Hooke believed fossils were the remains of once living things. The main problem, as Hooke saw it, was how to explain their presence in places where they do not seem to belong, and here he proposed the earth has changed since its creation. Land washes into the sea. Volcanic eruptions throw up land and mountains. Floods wash away valleys. Wind wear down rocks. If this supposition is accepted, then change in the organic world follows as a corollary. We know, Hooke argues, e.g., that some animals are found in certain habitats but not in others. Now if a certain habitat "have been swallowed up" then it is not improbable that the animals found there would be destroyed. We also know that not only are animals capable of breeding a broad varieties, such as we see in dogs, sheep, goats, pigeons, but also that the characteristics—'accidents' was the old fashion word he used—of some varieties suited them better to certain "Climate and Nourishment" and not others. If these animals were transplanted to a strange new place, then it is "not unlikely but that the like variation may follow; and hence I suppose 'tis that I find divers kinds of Petrify'd Shells [i.e., fossils], of which kind we have none now naturally produced . . ."8

But Hooke could not support his speculations with any evidence, and his audience in the learned Society remained unmoved. That evidence would be provided by Nicolaus Steno.

Nicolaus Steno

The first person to subject fossils to scholarly consideration was Nicolaus Steno (1638-1686), the Danish who is often called the founder of the science of geology. He was also a highly skilled anatomist. While on a visit to Italy, his patron Grand Duke Ferdinand de' Medici invited him to dissect before his court a huge shark that was caught off the coast of Tuscany. The event would change the history of how fossils was understood. Steno noticed the sharp and detailed similarities between the shark's teeth and some of the glossopetrae he had seen and realized that the resemblance was too perfect to be an accident. Just as fascinated, the Grand Duke decided to finance Steno's next project to study the geology of Tuscany. With his unusual insights he soon developed the idea of geological stratification, that some rocks were formed by layer by layer sedimentation, and that was how the remains of ancient creatures came to be buried within and turned into fossils. This idea was no mere speculation, but attended by clear evidence and explanation.

Born a Lutheran, Steno saw his explanation simply as a way of filling out the blanks in the book of Genesis, postulating that the deposition occurred twice, once during creation and once more during the great Flood. 5

Fossils were, henceforth, taken seriously as the remains of past living things; the question was how to relate them to the Christian and biblical conception of creation.

The Great Chain of Being

God created — Linnaeus arranged

Two years after Ray's death in 1705, Carl von Linne was born to a Lutheran minister in the rural Swedish town of Smaland. Carl von Linne is better known by his Latin name Carl Linnaeus. Encouraged by his father and a large parsonage garden, Linnaeus became obsessed with plants. Though trained in medicine, Linnaeus was so convinced of his calling as a systematist, he happily announced, "God created - Linnaeus arranged." He went on to develop a system of classification that was simple to use and easily understood, a system with far-reaching consequences, a system still in use today. First, Linnaeus cut through all the chaos of naming any organism by proposing that every organism should be identified by means of a binomial name, consisting of its genus and species, the former written with a capital initial letter. The genus would be any group that shares a unique set of common characteristics. Thus Magnolia acuminata pointed to a specific species acuminata of the genus Magnolia. Hymenolepis diminuta is the specific species (diminuta) of the genus of tapeworm Hymenolepis. Compare this with Achillea folis duplicato-pinnatis glabris laciniis linearibus acute laciniatis for a humble plant known to the English as milfoil. Additionally, by using Latin for such names, Linnaeus standardized the task at hand and quelled any nationalistic or ethnic sensitivities.

Secondly, Linnaeus developed a hierarchy in which every living thing may be organized. Linnaeus proposed five levels: kingdom, class, order, genus and species. Though Linnaeus was at his best working with plants, he extended his system of classification to animals. Significantly, he included humans into his schema, placing Homo sapien at the top of the chain in a class he created and called Primates, which also included monkeys and apes.

In the beginning Linnaeus believed, like most naturalists then, that God had created the array of distinct species that have remained unchanged to the present. His definitive work, Systema Naturae—the first edition only had fourteen pages, went through twelve editions during his lifetime, and some doubted if any species that was not listed in it really existed—was dedicated to God who created them all. In developing the system he did, Linnaeus was not interested in the relationship between the species. His hierarchy was a practical one: an order is higher than the genus only in that it included all the genera under it. All the species were different; that did not necessary imply that some were more advanced or perfect than others. The genus, e.g., simply includes all the species that share simliar characteristics, not that they are biologically related (in the evolutionary sense we might think of today). Some real life cases, however, had to be explained. The horse and the ass are two different species, which by definition means that they do not interbreed. But, occasionally, they do, and mules are produced. The mule, however, is sterile and, therefore, cannot be counted as a species. Linneaus and his disciples eventually came around to believe that such hybridization in plants may turn out hybrids that are fertile. If so, new species do in fact arise. The most startling case that need some serious reconsideration turned out to be the Peloria.

In 1741, one of Linnaeus' students brought to him a specimen of a plant which they immediately recognized as belonging to the genus Linaria. Except that its flower structure was very different. His first thought was that the new characteristics had been a trick of hybridization. Except that this new plant was fertile. Linnaeus was forced to recognize that, perhaps, new species do arise:

Nothing could be more miraculous than the story of this plant, in that the deformed offspring of a plant which normally produces irregular flowers, now produces regular ones. This is not only a deviation from its mother genus, but from the whole class; a unique phenomenon in botany. . . It is possible for new species to come into existence within the plant kingdom.

He duly named the new plant Peloria, Latin for 'monster.' Though Linnaeus was still only prepared to think of the origin of the new species as due to hybridization, evolution as a explanation for the origin of life on earth had taken its first toehold in the door of natural sciences.

Jean-Baptiste Lamarck

Jean-Baptiste Lamarck is today more often caricatured rather than remembered, even when he is referred to by name. In particular, Darwinians often set him up as a strawman against whom they might regal in the genius of their hero, and Lamarckianism is today a term useful for beating down opponents as much as for describing Lamarch's conception of organic 'evolution.'

Lamarck came from an impoverished aristocratic family from Picardy, France. In his teens his father died and he was forced to make a career for himself in the military; he distinguished himself during four years at the front of the French-Prussia war. Returning to civilian life after the war, he became a bank clerk but botany caught his interest. He also caught the attention of the Comte de Buffon, the director of the Jardin du Roi, the royal garden, and soon became a member of the inner circle at the Jardin. In the year that Linnaeus died, 1778, Lamarck published the first identification kit in which the user goes through a list of two-way choices—what is today called a dicotonomous key—for identifying plants. In contrast to Linnaeus' approach, which used a binomial Latin name, Lamarck chose to use the common names instead, thus making botany as a science accessive to everyone.

Lamarck managed to survive the murderous madness of the French Revolution, but when the Jardin du Roi was reorganized into the Museum d'Historie Naturelle, Lamarck was transferred to the zoological section and made curator of worms instead. It was a demotion, really. He was then 50, his (second) wife was pregnant, and he had six children.

Charles Darwin

The Beagle landed at Falmouth on 2 October 1836, where Darwin disembarked and never left the land in which he was born again. He became an instant success, not only with his father, who saw in him now a matured focused young man, but also in the scientific circles. Two years later he was elected a Fellow of the Royal Society. His journal of the voyage was soon published to great popular acclaim, and he settled down to sort out the collection of specimens he had brough back, and to brood about what he had seen and what they all mean. The idea of biogical evolution seemed to have hatched early during this season in his life, and he began to squirrel away his thoughts about the subject in a number of now famous notebooks, but he kept the subject close to himself. He married his cousin, Emma Wedgewood, and settled down to a comfortable reclusive life in Kent. He shared his thoughts on "the transmutation of species" (his favoured term for what we call evolution) with a few close friends, such as Joseph Hooker and Charles Lyell. Though urged by Lyell, especially, to publish his theory, Darwin hesitated. He published on many other subjects but postponed and postponed doing so with his theory. On 18 June 1858, twenty-two years after he left the Beagle, he received in his mailbox a parcel from a man who was then nine thousand kilometers away in the Celebes. He was horrified by the manuscript he found in the parcel. It had written up a theory "On the Tendency of Varieties to Depart Indefinitely From the Original Type" that corresponded so closely with his unpublished theory he confessed to his friend Lyell, "I never saw a more striking coincidence . . . Even his terms now stand as Heads of my Chapters."20 There are many today who feel that, had Darwin been a more honourable person, it would not be his name that came to be associated with the concept of evolution the way it is; it would have been Alfred Russel Wallace's, author of the manuscript and sender of the parcel.

Alfred Russel Wallace

Compared to Darwin, who came from a home that enabled him never to have to work a single day for wages, Alfred Russell Wallace came from a down-n-out family in Wales. Wallace was largely a self-taught man, his family never having enough to send him to proper schools. But he was highly intelligent (more so, in my opinion, than Darwin) and motivated. At an early age he was forced to work, first helping his brother surveying the then quickly developing canals that served as the arteries of the industrial revolution. It was, however, the acquaintance of a friend, Bates, who would reshape his destiny. Bates introduced Wallace to the world of insects. Soon hobby turned into serious business, and they decided to quit whatever it was they were doing to go collecting insects fulltime in the jungles of the Amazon. And Britain then had loads of wealthy people who wanted their own collections. With a loyal agent to act on his behalf in London, Bates and Wallace began making some serious money for themselves. Once there, Bates and Wallace decided that the best way to capitalize on their collection was to go separate ways. After ## years, Wallace decided he should head home (even if only temporarily). Just a few days after leaving port, however, the ship (a lady called Helen) caught fire. Everyone on board survived but but Wallace lost everything he was bringing home, every specimen and, especially, all his precious notes that would have allowed him to write credibly about his travels and exploits in the Amazons. It would have been the end of meaningful life if Wallace was made of weaker stuff than he was. Steven, however, had faithfully took out an insurance on Wallace's stuff, and with the money Wallace left for South-East Asia, ending up spending most of his time in the Celebes. (In the end he did get to write about his exploits, The Malay Achipelago