History of evolutionary thought 1 Pre-Darwinian background

1. History of evolutionary thought1 Pre-Darwinian background

2. Greek philosophers Anaximander 6th century BC Empedocles 5th century BC Plato 4th century BC Aristotle 4th century BC Pliny the Elder 1st century AD Lactantius 3rd century AD

3. Idealism Two coexisting worlds Western Thought: Greek Philosophers Plato Ideal, eternal, real world vs Imperfect world -apparent to humans -all organisms perfectly-variation within adaptedpopulations part of thisillusory world that our senses perceive

4. Greek philosophers Anaximander 6th century BC Empedocles 5th century BC Plato 4th century BC Aristotle 4th century BC Pliny the Elder 1st century AD Lactantius 3rd century AD

5. Western Thought: Greek PhilosophersAristotle • Scala Naturae - Great Chain of Being • hierarchy and order in the natural world • order is a product of God’s creation • species are fixed entities • humans are the link between physical and spiritual worlds

6. Aristotle’s Scale of Nature - Great Chain of Being angels complex humans most perfect animals most imperfect plants simple rocks

7. Greek philosophers Anaximander 6th century BC Empedocles 5th century BC Plato 4th century BC Aristotle 4th century BC Pliny the Elder 1st century AD Lactantius 3rd century AD

8. Western Thought: Judeo-Christian Culture The School of Natural Theology Adaptations of organisms reflect God’s design St Thomas Aquinas (13th century) Summa Theologica: Whatever lacks knowledge cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is directed by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.

9. Western Thought: Judeo-Christian CultureThe School of Natural Theology Leibniz (1646-1716) – Natura non facit saltum suggested gaps in the GCoB caused by some species being extinct

10. Buffon (1707-1788) Les espèces sont les seuls êtres de la nature Fixity of species: New spp had not appeared during recorded history How then could individuals of a single spp be separated from others of the same kind and become transformed into a new spp? Where are all the missing links between existing spp if transformation from one to the other has taken place?

11. Buffon (1753) Natural History (4th vol) Not only the ass and the horse, but also man, the apes, the quaduped, and all the animals, might be regarded as constituting but a single family…If it were admitted that the ass is of the family of the horse, and differs from the horse only because it has varied from the original form, one could equally well say that the ape is of the family of man, that he is degenerate man, that man and ape have a common origin; that, in fact, all the families, among plants as well as animals, have come from a single stock, and that all animal are descended from a single animal, from which have sprung in the course of time, as a result of progress or of degeneration, all the other races of animals.

12. Western ThoughtThe School of Natural Theology Reverend William Paley in Natural Theology (1802) “when we come to inspect the watch, we perceive. . . that its several parts are framed and put together for a purpose, e.g. that they are so formed and adjusted as to produce motion, and that motion so regulated as to point out the hour of the day; that if the different parts had been differently shaped from what they are, or placed after any other manner or in any other order than that in which they are placed, either no motion at all would have been carried on in the machine, or none which would have answered the use that is now served by it. . . . the inference we think is inevitable, that the watch must have had a maker -- that there must have existed, at some time and at some place or other, an artificer or artificers who formed it for the purpose which we find it actually to answer, who comprehended its construction and designed its use…”

13. Scientific advances that influenced Darwin

14. Scientific advances that influenced Darwin: Systematics: Linnaeus Carolus Linnaeus (1754): Reflections on the study of nature If the Maker has furnished this globe, like a museum, with the most admirable proofs of his wisdom and power; if this splendid theater would be adorned in vain without a spectator; and if man the most perfect of all his works is alone capable of considering the wonderful economy of the whole; it follows that man is made for the purpose of studying the Creator’s work and that he may observe in them the evident marks of divine wisdom.

15. Recognized species as the fundamental unit defined by reproduction Developed a system of categorizing species Binomial nomenclature Hierarchy of categories above genus Linnaeus - Father of Taxonomy

16. Scientific advances that influenced Darwin: Geology: Hutton and Lyell Current geological processes that we observe today are responsible for all geologic features. • Two components of this view: • Gradualism-profound change is the cumulative product of slow, continuous change (Hutton) • Uniformitarianism-geological processes haven’t changed over the course of history (Lyell) • View leads to the conclusion: • Earth is very old!

17. Scientific advances that influenced Darwin: Evolution: Lamarck • Lamarck’s Theory of Evolution (1809) • species originate by spontaneous generation • “nervous fluid” causes species to progress down unique path • no species go extinct

18. The Mechanism for Lamarck’s Theory 1. Use and Disuse of Organs 2. Inheritance of Acquired Characteristics

19. Lamarck First to suggest branching rather than linear tree

20. Scientific advances that influenced Darwin: Economics: Malthus Malthus (1798):Essay on the Principle of Population The rate of human population growth exceeds the the rate of increase in the food supply….leads to human famines. More organisms are born than can survive. Organisms compete with one another to survive.

21. Scientific advances that influenced Darwin: Paleontology: Cuvier Father of paleontology whose studies of fossils revealed: • Stratification-fossils were deposited in layers of different ages. • Change through time-older fossils were less similar to modern forms, e.g. forms changed through time. • Extinction-locations where fossils from older strata were lost, e.g. species went extinct

22. Impressions of organisms mineralized in rocks Discovery of Fossils

23. Paleontology: Cuvier • Proposed the following theory of catastrophism to explain his observations • Catastrophism-major changes in strata are the result of catastrophic events, e.g. floods or droughts • Species are lost due to local extinctions as a result of catastrophe • New species appear in next strata as a result of colonization

24. Scientific advances that influenced Darwin: Evolution: Wallace Alfred Russel Wallace 1823-1913 Darwin’s contemporary Came to same conclusion as Darwin They presented their work together in 1858

25. Truth is born into this world only with pangs and tribulations, and every fresh truth is received unwillingly. To expect the world to receive a new truth, or even an old truth, without challenging it, is to look for one of those miracles which do not occur. Alfred Russel Wallace