A digression into the History of Evolution

1. A digression into the History of Evolution

2. Carl Linnaeus (1707-1778) • Father of Taxonomy • He was born 1707, 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) • Formulated one of the first formal theories on evolution in Zoonomia, or, The Laws of Organic Life (1794-1796). • Presented evolutionary ideas in verse, in particular in the posthumously published poem The Temple of Nature. • Discussed ideas that his grandson elaborated on sixty years later, such as how life evolved from a single common ancestor, forming "one living filament". • Some of his ideas are quite close to those of Lamarck • Saw 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; never won the acceptance and esteem of his colleagues Buffon and Cuvier, and he died in poverty and obscurity. • Lamarck is associated 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 2 • 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 HistorieNaturelle, 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 (Wallace’s Line)

12. Étienne Geoffroy St. Hilaire (1772-1844) • 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

13. 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." Richard Owen (1804-1892)

14. Owen’s Vertebrate Archetype

15. Adam Sedgwick (1785-1873) • Sedgwick was one of several great figures in the Heroic Age of geology • Sedgwick's own geological views were generally catastrophic -- he believed that the history of the Earth had been marked by a series of cataclysmic events. • Defined major geological era classified by different fossil compositions • Sedgwick believed in the Divine creation of life over long periods of time, by "a power I cannot imitate or comprehend – • What Sedgwick objected to was the apparent amoral and materialist nature of Darwin's proposed mechanism, natural selection, which he thought degrading to humanity's spiritual aspirations.

16. Charles Lyell • Father of modern geology

17. Charles Darwin 1809-1882

18. Louis Agassiz (1807-1873) • One of the great scientists of his day, and one of the "founding fathers" of the modern American scientific tradition, Louis Agassiz remains something of a historical enigma. A great systematist and paleontologist, a renowned teacher and tireless promoter of science in America, also a lifelong opponent of Darwin's theory. • The son of a minister, Agassiz was born in the French-speaking part of Switzerland. • Studied comparative anatomy with Cuvier • In 1846, Agassiz came to the United States; accepted a professorship at Harvard.

19. More Agassiz • Agassiz continued Cuvier's catastrophism theory -- the Earth had been periodically wracked by global catastrophes, after each of which new species of animals and plants had appeared. Followers of Cuvier had suggested that the Biblical Flood was the last catastrophe. Agassiz replaced the Flood with his glaciers • He believed glaciers had been formed instantaneously all over the world; he called glaciers "God's great plough," and tried unsucessfully to find evidence of glaciation in Brazil. • Agassiz's works on living and fossil fish and on glaciers have remained classics. His work on glaciers revolutionized geology. He trained and influenced a generation of American zoologists and paleontologists, including Alpheus Hyatt, William Healey Dall, David Starr Jordan, Nathaniel Shaler, and Edward S. Morse. He left a mark on the development and the practice of American science, and brought science to "the man in the street" as no one else had before. People from all over the world read his books, sent him specimens, and asked his advice. By the time of his death, on December 14, 1873, he was publicly recognized as America's leading scientist.

20. Thomas Henry Huxley (1825-1895) • Thomas Henry Huxley was one of the first adherents to Darwin's theory of evolution by natural selection, and did more than anyone else to advance its acceptance among scientists and the public alike. • Huxley was a passionate defender of Darwin's theory -- so passionate that he has been called "Darwin's Bulldog".

21. Huxley • I finished your book yesterday. . . Since I read Von Baer's Essays nine years ago no work on Natural History Science I have met with has made so great an impression on me & I do most heartily thank you for the great store of new views you have given me. . .As for your doctrines I am prepared to go to the Stake if requisite. . .I trust you will not allow yourself to be in any way disgusted or annoyed by the considerable abuse & misrepresentation which unless I greatly mistake is in store for you. . . And as to the curs which will bark and yelp -- you must recollect that some of your friends at any rate are endowed with an amount of combativeness which (though you have often & justly rebuked it) may stand you in good stead -- I am sharpening up my claws and beak in readiness • Letter of T. H. Huxley to Charles Darwin, November 23, 1859, regarding the Origin of Species

22. Even More Huxley • Huxley did not blindly follow Darwin's theory, and critiqued it even as he was defending it. In particular, where Darwin had seen evolution and a slow, gradual, continuous process, Huxley thought that an evolving lineage might make rapid jumps, or saltations. • Huxley explicitly presented evidence for human evolution. • He is best known for his famous debate in June 1860, at the British Association meeting at Oxford. His opponent, Archbishop Samuel Wilberforce, was known as "Soapy Sam" for his renowned slipperiness in debate. Wilberforce was coached against Huxley by Richard Owen. During the debate, Archbishop Wilberforce ridiculed evolution and asked Huxley whether he was descended from an ape on his grandmother's side or his grandfather's. Accounts vary as to exactly what happened next, but according to one telling of the story, Huxley muttered "The Lord hath delivered him into my hands," and then rose to give a brilliant defense of Darwin's theory, concluding with the rejoinder, "I would rather be the offspring of two apes than be a man and afraid to face the truth."

23. Ernst Haeckel (1834-1919) • Haeckel is one of many thinkers who believed that all species were historical entities (lineages) but did not share Darwin's enthusiasm for natural selection as the main mechanism for generating the diversity of the biological world. Haeckel instead believed that the environment acted directly on organisms, producing new races. • Although best known for the famous statement "ontogeny recapitulates phylogeny", he also coined many words commonly used by biologists today, such as phylum, phylogeny, and ecology. On the other hand, Haeckel also stated that "politics is applied biology", a quote used by Nazi propagandists. The Nazi party, rather unfortunately, used not only Haeckel's quotes, but also Haeckel's justifications for racism, nationalism and social darwinism.

24. Francis Galton 1822-1911 • Galton developed interest in heredity, and the publication of the Origin of Species (1859) by Charles Darwin won Galton's immediate support. Impressed by evidence that distinction of any kind is apt to run in families, Galton made detailed studies of families conspicuous for inherited ability over several generations. He then advocated the application of scientific breeding to human populations. These studies laid the foundation for the science of eugenics (a term he invented), or race improvement, and led to the publication of Hereditary Genius (1869) and English Men of Science: Their Nature and Nurture (1874). • Biometriction and correlation, Mendel’s Laws

25. The Modern SynthesisThe Modern Synthesis describes the fusion (merger) of Mendelian genetics with Darwinian evolution that resulted in a unified theory of evolution. It is sometimes referred to as the Neo-Darwinian theory. The Modern Synthesis was developed by a number of now-legendary evolutionary biologists in the 1930s and 1940s.

26. Hugo de Vries (1848-1935) • A Dutch botanist who proposed the mutation theory based on experiments with the evening primrose. However, most of the changes he observed were not gene mutations but a result of other phenomena such as chromosome changes and unusual combinations. • Rediscovered Mendel’s laws independently

27. Ronald Fisher • Sir Ronald Aylmer Fisher (1890 - 1962) was a British mathematician and geneticist whose book, The Genetical Theory of Natural Selection (1930) proved that Mendelian geneticswere essential underlying mechanism of Darwiniam evolution. His work laid the foundations for statistical analysis of all subsequent experiments in the life sciences. • He described a process called runaway sexual selection to explain exaggerated characters of organisms such as the peacock's tail. • • He explained why sexual species maintain a sex ratio of roughly 50:50. • • He developed a model of adaptive evolution which describes the relationship between the form of a character and its fitness. • • He proposed that accelerated evolution is an advantage of sexual reproduction that may outweigh the enormous costs of sex.

28. John Haldane (1892 - 1964 • John Burdon Sanderson Haldane (1892 - 1964) had a wide range of interests in biology. He began by studying the respiratory system, using himself as an experimental subject. He then turned to biochemistry, and finally to genetics. • Here are some of his main contributions to evolutionary biology: He produced mathematical models of natural selection which allow gene frequencies to be predicted; He described a cost of natural selection, and investigated what limits this might place on the rate of evolution. • • He suggested that selection can maintain a polymorphism when the heterozygote is fitter than either homozygote (see heterozygotic advantage). • Haldane's work, together with that of R.A. Fisher and Sewall Wright, played a central part in the construction of the modern synthesis.

29. Sewell Wright Sewall Wright (1889 - 1988) was an American geneticist who played a central part in the foundation of the modern synthesis, together with R.A. Fisher and J.B.S Haldane. • Wright noticed that genes can disappear from a small population not because of selection, but because of chance - genetic drift. Wright attempted a comprehensive, realistic model of evolution, including complex interactions between genes, random effects, selection between and within populations, and migration.

30. Theodosius Dobzhansky1900 - 1975 • Dobzhansky's studies in population genetics served as a basis for his explanation of how the evolution of races and species could have come about through adaptation. • He discovered that successful species tend to have a wide variety of genes that, while they do not appear to be useful to the organism in its present environment, do provide a species as a whole with genetic diversity. This diversity enables the species to adapt effectively to changes in the surrounding environment.