Chapter 2 Biology:

1. Chapter 2Biology: From natural philosophy to Darwin

2. The History of Evolutionary Thought: Pre 1800 • Comparative Anatomy: Andreas Vesalius • Observation and Natural Theology: William Harvey & William Paley • Fossils and the Birth of Paleontology: Nicholas Steno • Nested Hierarchies, the Order of Nature: Carolus Linnaeus • Old Earth, Ancient Life: Georges-Louis Leclerc, Comte de Buffon • The Ecology of Human Populations: Thomas Malthus

3. The History of Evolutionary Thought: 1800s • Extinctions: Georges Cuvier • Early Concepts of Evolution: Jean Baptiste Lamarck • Developmental Similarities: Karl von Baer • Biostratigraphy: William Smith • Uniformitarianism: Charles Lyell • Discrete Genes Are Inherited: Gregor Mendel • Natural Selection: Charles Darwin & Alfred Russel Wallace

4. The History of Evolutionary Thought: 1800s • Early Evolution and Development: Ernst Haeckel • Biogeography: Wallace and Wegener • Fossil Hominids, Human Evolution: Thomas Huxley & Eugene Dubois • Chromosomes, Mutation, and the Birth of Modern Genetics: Thomas Hunt Morgan

5. The History of Evolutionary Thought: 1900 to present • Random Mutations and Evolutionary Change: Ronald Fisher, JBS Haldane, & Sewall Wright • Starting "The Modern Synthesis": Theodosius Dobzhansky • Speciation: Ernst Mayr • DNA, the Language of Evolution: Francis Crick & James Watson • Radiometric Dating: Clair Patterson • Endosymbiosis: Lynn Margulis

6. The History of Evolutionary Thought: 1900 to present • Evolution and Development for the 21st Century: Stephen Jay Gould • Genetic Similarities: Wilson, Sarich, Sibley, & Ahlquist

7. The History of Evolutionary Thought • Just as life has a history, science has a history. • Understanding the history of evolutionary thinking illuminates the nature of science. • In this section, you will see how study in four disciplinary areas — Earth's history, life's history, mechanisms of evolution, and development and genetics — has contributed to our current understanding of evolution.

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9. Founders of Natural Science From Ancient Times to the Enlightenment

10. Evolution = change • Concept that species change over time, has roots in antiquity • Ancient Greeks • Romans • Chinese • Medieval Islamic science.

11. Evolution in Greece • Philosophical notion of descent with with modification • Concept of origination • All things originated from water or air • All things descended from one central, guiding principle • Aristotle (384 – 322 BC) • Suggests a transition between the living and the nonliving • Theorizes that in all things there is a constant desire to move from the lower to the higher, finally becoming the divine • Purpose for every organism, fixity of species, ladder of life (Scala Naturae)

12. St. Augustine of Hippo • Theistic evolution? • Believed that God created all things ex nihilo, instantaneously in the form of seminal principals • Seeds • Believe in spontaneous generation • Therefore, seeds existed in living and non-living matter • “In the beginning” was the beginning of time • Very important idea for creationism - St. Augustine of Hippo (354-430 AD)

13. St. Augustine of Hippo • Creation in 7 days - may not be 24 hr days • “Day” was figurative • Adam created < 5600 years • Nature has the potential to produce and evolve? • Argument about what he meant by seeds • Could they yield molecules to living things – theistic creation? • or - Were they fixed at the time of creation?

14. Medieval Theories • Evolution was not discussed • Dominated by the Christian theory of special creation • All living things came into existence in unchanging forms due to divine will • Confused by the idea of spontaneous generation • Rotten meat gave rise to maggots • Rags produced rats • Frogs came from slime • This concept prevented both genetic thinking and speculation about evolution or descent with modification

15. Galileo, Bacon, Descartes • Physicists, Astronomers break with traditional beliefs • Solar system debate - earth versus sun as center of the universe Galileo Galilei 1564 –1642

16. John Ray John Ray 1627-1705 • Supported the theory that fossils were once living organisms • Died in “Flood.” • Fossils that resembled no living organism due to ignorance of the full range of living organisms • Insight that fossils were once living organisms was a significant advance over most other theories of his time, • Questions as to what fossils might indicate about the Earth's age and history would be investigated by generations of paleontologists.

17. The History of Evolutionary Thought: Pre 1800 • Andreas Vesalius (1514-1564) • Flemish anatomist • Corrected errors in Galens’ early dissection work • (Greek physician) • Famous for his exquisite anatomical charts • Research led to conclusion that humans are not unique, share many characteristics with other animals Comparative Anatomy: Andreas Vesalius

18. The History of Evolutionary Thought: Pre 1800 • William Harvey (1578 –1657) • English physician • Discovered how blood circulates • Observation and Natural Theology: William Harvey & William Paley

19. John Ray (1628-1705) • Often referred to as the father of natural history in Britain. • Published systematic works on plants, birds, mammals, fish, and insects • brought order to the chaotic mass of names in use by the naturalists of his time. • Searched for the "natural system," a classification of organisms that would reflect the Divine Order of creation. • Classified plants by overall morphology • Would become a powerful tool for evolutionary biologists trying to infer evolutionary relationships

20. Immanuel Kant (1724-1804) • First ideas about the Big Bang that created the solar system • Developed a concept of descent similar to modern ideas • Speculated that organisms may have come from a single ancestral source • Based on similarities between organisms • an orang-outang or a chimpanzee may develop the organs which serve for walking, grasping objects, and speaking-in short, that lie may evolve the structure of man, with an organ for the use of reason, which shall gradually develop itself by social culture

21. The History of Evolutionary Thought: Pre 1800 • William Paley (1743–1805) • 1802: Natural Theology: or, Evidences of the Existence and Attributes of the Deity, Collected from the Appearances of Nature, • Laid out a full exposition of natural theology, the belief that the nature of God could be understood by reference to His creation, the natural world. • Introduced one of the most famous metaphors in the philosophy of science, the image of the watchmaker. • Richard Dawkins – The Blind Watchmaker • Observation and Natural Theology: William Harvey & William Paley

22. William Paley • Darwin took from his reading of Paley a belief in adaptation -- that organisms are somehow fit for the environments in which they live, that their structure reflects the functions they perform throughout their lives. • Living organisms, Paley argued, are even more complicated than watches, in a degree which exceeds all computation. How else to account for the often amazing adaptations of animals and plants? Only an Intelligent Designer could have created them, just as only an Intelligent Watchmaker can make a watch: …

23. . . . 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.

24. The History of Evolutionary Thought: Pre 1800 Nicolas Steno (1638-86): Father of geology and stratigraphy Fossils and the Birth of Paleontology: Nicholas Steno

25. Some recognized record of historical change • Niels Stensen (better known as Steno) • Danish anatomist • Recognized record of historical change • Proposed that fossils belonged to once living creatures • Fossils were snapshots of life at different moments in Earth’s history • Birth of paleontology • Law of Superposition • Rock layers formed slowly over time • Older rocks lie below younger rocks

26. Preludes to Evolution

27. Early naturalists classified life’s diversity Carl Linnaeus (1707-78): Father of modern taxonomy Nested Hierarchies, the Order of Nature: Carolus Linnaeus

28. Carl von Linne' Latinized to Carolus Linnaeus Swedish naturalist Followed in footsteps of Aristotle who also tried to categorize living organisms Plant classification was based entirely on floral reproductive organs Identified every known species according to a standard binomial nomenclature, Binomial epithet (genus species: Homo sapiens or Homosapiens) Humans as primates

29. Carolus Linnaeus • At first, he believed in the fixed nature of species, but was later swayed by hybridization experiments in plants, which could produce new species. • Saw the new species created by plant hybridization to have been part of God's plan • Maintained belief in special creation in the Garden of Eden

30. Erasmus Darwin (1731-1802) • Darwin’s grandfather • Distinguished naturalist • Argued that all life could a have a single common ancestor • Struggled with the concepts of a mechanism for this descent • Discussed the effects of competition and sexual selection on possible changes in species • Believed that the use or disuse of parts could in itself make them grow or shrink, and that unconscious striving by the organism was responsible for adaptation.

31. Georges-Louis Leclerc, Comte de Buffon (1707-1788) • Fascinated by the diversity of life; and was not content with existing explanations of the natural world • During the eighteenth century, two church doctrines provided sweeping biblical explana- tions for most questions about biological diversity: • Separate Creation, the idea that all creatures have been created independently of one another by God and organized into a hierarchy ("chain of being") with Man occupying the most elevated rank beneath God; • The 6,000 year limit on the age of the planet.

32. Early ideas about evolution Georges Buffon (1707-88) • Georges-Louis Leclerc, Comte de Buffon • Old Earth, Ancient Life • Earth formed according to laws of physics and chemistry, non-biblical explanation • Older than previously thought • > 70,000 years • Spontaneous origins of life • Species emerged as distinct types • Diverseenvironments give rise to new varieties (Proto-evolution)

33. Buffon believed that modern Indian and African elephants were migratory descendants of Siberian mammoths.

34. Buffon • Historie Naturelle • 44 volume encyclopedia describing everything known about the natural world, • Discussed the similarities of humans and apes and talked about common ancestry of Man and apes. • Although Buffon believed in organic change, he did not provide a coherent mechanism for such changes. • Thought that the environment acted directly on organisms through what he called "organic particles.“ • Fats separate, salts dissolve

35. Buffon • Also published Les Epoques de la Nature (1788) • Openly suggested that the planet was much older than the 6,000 years proclaimed by the church • Discussed concepts very similar to Charles Lyell's "uniformitarianism" which were formulated 40 years later. • Different approach from others of his time • Empirical and philosophical pursuits of causes and explanations beyond the accepted explanations of his time • Biogeography of mammals (predatory cats) • Concept of speciesbased on reproductive isolation (basis for modern biological species concept)

36. The Ecology of Human Populations: Thomas Malthus • An Essay on the Principle of Population as it affects the Future Improvement of Society • Population growth vs. the food supply • Looked at humans as populations of individuals; studied them like an ecologist studies populations • Influenced Darwin & Wallace • Competition for resources • Struggle for existence Thomas Malthus (1766-1834)

37. The History of Evolutionary Thought: 1800s

38. The History of Evolutionary Thought: 1800s • Extinctions: Georges Cuvier • Early Concepts of Evolution: Jean Baptiste Lamarck • Developmental Similarities: Karl von Baer • Biostratigraphy: William Smith • Uniformitarianism: Charles Lyell • Discrete Genes Are Inherited: Gregor Mendel • Natural Selection: Charles Darwin & Alfred Russel Wallace

39. Georges Cuvier (1769-1832) • Founded vertebrate paleontology as a scientific discipline and created the comparative method of organismal biology • Cuvier saw organisms as integrated wholes, in which each part's form and function were integrated into the entire body. • No part could be modified without impairing this functional integration

40. Georges Cuvier • Paleontology provided evidence that life changed • Did not believe in organic evolution • Any change in an organism's anatomy would have rendered it unable to survive • Studied mummified cats and ibises brought back from Napoleon's invasion of Egypt, and showed that they were no different from their living counterparts; • Used this to support his claim that lifeforms did not evolve over time.

41. Georges Cuvier • Established the fact of the extinction of past lifeforms • Believed that the Earth was immensely old • Most of its history conditions had been more or less like those of the present. • Periodic natural "revolutions", or catastrophes (had befallen the Earth; each one wiped out a number of species. (99% of all species are now extinct)

42. Georges Cuvier • Organisms are functional wholes • Any change in one part would destroy the delicate balance • The functional integration of organisms meant that each part of an organism, could give info about the whole • It was therefore possible to reconstruct organisms from fragmentary remains, based on rational principles. • Had a amazing ability to reconstruct organisms from fragmentary fossils, and many of his reconstructions turned out to be strikingly accurate. • He based his reconstructions less on rational principles than on his deep knowledge of comparative anatomy of living organisms.

43. Early Concepts of Evolution • Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck • Species not fixed and immutable, but rather in a constantly changing state. • Envisioned evolutionary change for the first time • Presented a multitude of different theories that he believed combined to explain descent with modification of these changing species Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck (1744-1829)

44. Early Concepts of Evolution • Lamarck: Inheritance of acquired characteristics • Evolution by natural processes • Adaptation through inheritance of acquired characteristics • Organism could pass on to its offspring any characteristics it had acquired in its lifetime • Change through use and disuse • Example: giraffes neck stretching to reach food

47. So why the long neck?

49. Neck is used in combat between males for mating rights with females. The longer the neck, the more powerful the blow to the opponent.

50. Lamarck (cont) • Had false beliefs about inheritance • Argued for strong effects of the use and disuse of parts • Parts change size or shape in accordance with their use • Believed that all organisms fundamentally want to adapt themselves to their environment, and so they strive to become better adapted (more complex)