A digression into the History of Evolution and the Adaptive Landscape

1. A digression into the History of Evolution and the Adaptive Landscape

2. Carl Linnaeus (1707-1778)  Father of Taxonomy He was born on May 23, 1707, at Stenbrohult, in the province of Sm�land in southern Sweden. His father, Nils Ingemarsson Linnaeus, was both an avid gardener and a Lutheran pastor, Linnaeus went to the Netherlands in 1735, promptly finished his medical degree at the University of Harderwijk, and then enrolled in the University of Leiden for further studies. That same year, he published the first edition of his classification of living things, the Systema Naturae.

3. Was Linnaeus an evolutionist? It is true that he abandoned his earlier belief in the fixity of species, and it is true that hybridization has produced new species of plants, and in some cases of animals. Yet to Linnaeus, the process of generating new species was not open-ended and unlimited. Whatever new species might have arisen from the primae speciei, the original species in the Garden of Eden, were still part of God's plan for creation, for they had always potentially been present.

4. Erasmus Darwin (1731-1802) As a naturalist, he formulated one of the first formal theories on evolution in Zoonomia, or, The Laws of Organic Life (1794-1796). He also presented his evolutionary ideas in verse, in particular in the posthumously published poem The Temple of Nature. Although he did not come up with natural selection, he did discuss ideas that his grandson elaborated on sixty years later, such as how life evolved from a single common ancestor, forming "one living filament". Although some of his ideas on how evolution might occur are quite close to those of Lamarck, Erasmus Darwin also talked about how competition and sexual selection could cause changes in species: "The final course of this contest among males seems to be, that the strongest and most active animal should propogate the species which should thus be improved".

5. Jean-Baptiste Lamarck (1744-1829) Lamarck's scientific theories were largely ignored or attacked during his lifetime; Lamarck never won the acceptance and esteem of his colleagues Buffon and Cuvier, and he died in poverty and obscurity. Today, the name of Lamarck is associated merely with a discredited theory of heredity, the "inheritance of acquired traits." Charles Darwin wrote in 1861: Lamarck was the first man whose conclusions on the subject excited much attention. This justly celebrated naturalist first published his views in 1801. . . he first did the eminent service of arousing attention to the probability of all changes in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition.

6. Jean-Baptiste Lamarck (1744-1829) part deu Lamarck published a series of books on invertebrate zoology and paleontology. Of these, Philosophie zoologique, published in 1809, most clearly states Lamarck's theories of evolution Lamarck's contributions to evolutionary theory, his works on invertebrates represent a great advance over existing classifications; he was the first to separate the Crustacea, Arachnida, and Annelida from the "Insecta." His classification of the mollusks was far in advance of anything proposed previously; Lamarck broke with tradition in removing the tunicates and the barnacles from the Mollusca. He also anticipated the work of Schleiden & Schwann in cell theory in stating that: . . . no body can have life if its constituent parts are not cellular tissue or are not formed by cellular tissue.

7. Georges-Louis Leclerc, Comte de Buffon (1707-1788) It is not the average person who questions two thousand years of dogma, but that is what Buffon did: 100 years before Darwin, Buffon, in his Historie Naturelle, a 44 volume encyclopedia describing everything known about the natural world, wrestled with the similarities of humans and apes and even talked about common ancestry of Man and apes. Although Buffon believed in organic change, he did not provide a coherent mechanism for such changes. He thought that the environment acted directly on organisms through what he called "organic particles".

8. Georges Cuvier (1769-1832) Almost single-handedly, he founded vertebrate paleontology as a scientific comparative method of organismal biology extinction of past lifeforms Cuvier's insistence on the functional integration of organisms led him to classify animals into four "branches," or embranchements: Vertebrata, Articulata (arthropods and segmented worms), Mollusca (which at the time meant all other soft, bilaterally symmetrical invertebrates), and Radiata (cnidarians and echinoderms). For Cuvier, these embranchements were fundamentally different from each other and could not be connected by any evolutionary transformation.

9. Thomas Malthus (1766-1834) Malthus was a political economist who was concerned about, what he saw as, the decline of living conditions in nineteenth century England. He blamed this decline on three elements: The overproduction of young; the inability of resources to keep up with the rising human population; and the irresponsibility of the lower classes. What "struck" Darwin in Essay on the Principle of Population (1798) was Malthus's observation that in nature plants and animals produce far more offspring than can survive, and that Man too is capable of overproducing if left unchecked.

10. Charles Darwin, from his autobiography. (1876) "In October 1838, that is, fifteen months after I had begun my systematic inquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long- continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The results of this would be the formation of a new species. Here, then I had at last got a theory by which to work".

11. Alfred Russel Wallace 1823-1913 Cofounder of Natural Selection 1st Biogeographer

12. Geoffroy asked the question: "Can the organization of vertebrated animals be referred to one uniform type?" The answer for Geoffroy was yes: he saw all vertebrates as modifications of a single archetype, a single form. Vestigial organs and embryonic transformations might serve no functional purpose, but they indicated the common derivation of an animal from its archetype. Cuvier disagreed "If there are resemblances between the organs of fishes and those of the other vertebrate classes, it is only insofar as there are resemblances between their functions �tienne Geoffroy St. Hilaire (1772-1844)

13. More on Geoffrey Geoffroy spent much time drawing up rules for deciding when structures in two different organisms were variants of the same type -- in modern terminology, when they were homologous. His criterion was connections between parts: structures in different organisms were the same if their parts were connected to each other in the same pattern. It would be an error to call Geoffroy an evolutionary biologist in anything like the modern sense. Geoffroy's field was morphology -- the study of form, pure and simple, not of the evolutionary history of forms. The archetypal forms of Geoffroy's "transcendental zoology" were abstractions, not once-living ancestors; shared archetypal form did not necessarily indicate common ancestry. As Charles Darwin described his work in 1859, in The Origin of Species: What can be more curious than that the hand of a man, formed for grasping, that of a mole for digging, the leg of the horse, the paddle of the porpoise, and the wing of the bat, should all be constructed on the same pattern, and should include the same bones, in the same relative positions? Geoffroy St. Hilaire has insisted strongly on the high importance of relative connexion in homologous organs: the parts may change to almost any extent in form and size, and yet they always remain connected together in the same order.

14. Richard Owen (1804-1892) Owen synthesized French anatomical work, especially from Cuvier and Geoffroy, with German transcendental anatomy. He gave us many of the terms still used today in anatomy and evolutionary biology, including "homology". Owen famously defined homology in 1843 as "the same organ in different animals under every variety of form and function." To take one example of homology: Structures as different as a bat's wing, a seal flipper, a cat's paw and a human hand nonetheless display a common plan of structure, with identical or very similar arrangements of bones and muscles. Taking homology to its conclusion, Owen reasoned that there must exist a common structural plan for all vertebrates, as well as for each class of vertebrates. He called this plan the archetype; his vertebrate archetype is illustrated below. Owen synthesized French anatomical work, especially from Cuvier and Geoffroy, with German transcendental anatomy. He gave us many of the terms still used today in anatomy and evolutionary biology, including "homology". Owen famously defined homology in 1843 as "the same organ in different animals under every variety of form and function." To take one example of homology: Structures as different as a bat's wing, a seal flipper, a cat's paw and a human hand nonetheless display a common plan of structure, with identical or very similar arrangements of bones and muscles. Taking homology to its conclusion, Owen reasoned that there must exist a common structural plan for all vertebrates, as well as for each class of vertebrates. He called this plan the archetype; his vertebrate archetype is illustrated below.