Course Objectives Describe the importance of JeanBaptiste Lamarck Charles Darwin Alfred Wallace Charles Lyell Stephen Jay Gould to the development of evolutionary theory Describe five ways that fossils can form including amber tar pits petrification sedimentary rocks and ice ID: 1027089
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1. Chapter 15 Darwin and Evolution
2. Course ObjectivesDescribe the importance of Jean-Baptiste Lamarck, Charles Darwin, Alfred Wallace, Charles Lyell, Stephen Jay Gould, to the development of evolutionary theory.Describe five ways that fossils can form including amber, tar pits, petrification, sedimentary rocks, and ice.List the four Eras in order and give a brief description for each: Precambrian, Paleozoic, Mesozoic, Cenozoic.
3. 15. 1 History of Evolutionary Thought18th CenturyVariation of species began to inspire thoughts on the origin of all the different species.Evolution was just beginning to be introduced.General concept:Evolution : the change in species over time.Evolution as an idea on the formation of many species was around before Darwin
4. Mid 18th Century ContributionsTaxonomy & Carolus Linnaeus (1707-78)Developed binomial nomenclature of classification of organisms but still at the time believed in special creation and the “fixity” of species.Discovery and interest in fossils and the study of extant (living today) species.Was looking for the “perfect form” of each species based on philosophical ideas of ancient Greeks Scala Naturae: A sequential ladder of life with the simplest (lowest) life forms at the bottom and the most complex (highest) at the top (i.e Man)
5. Late 18th/ Early 19th Century ContributionsCuvier & Catastrophism Used comparative anatomy to classify organismsfounded the science of Paleontologya staunch advocate of special creation & fixity of species so had a problem when faced with a successional series of fossils So proposed that a series of catastrophes killed of the organisms and then a special creation event made all new ones.Students coined this idea as “catastrophism”
6. Late 18th/ Early 19th Century ContributionsLamarck and Acquired CharacteristicsJean-Baptiste de Lamarck (1744-1829)Was the first biologist to offer a mechanism for how evolution occurred and to link diversity with adaptation to environmentInheritance of Acquired CharacteristicsThis is the general idea that adults do or use something that causes a characteristic to appear and then, the adults pass on that characteristic that they have acquired to their offspring. “use and disuse”
7. Charles DarwinCharles Darwin (809-1882)Attended medical school at age 16 but found that his “sensitive nature” made it difficult for him Attended Christ College at Cambridge for divinity school Took classes on biology and geology because of his interests While at Cambridge, worked closely with Rev. John Henslow and gained geology fieldwork experience under Adam Sedgewick.After graduation, took a naturalist position on the HMS Beagle While on the Beagle (5 years) traveled in Southern hemisphere and made many observations and collected many specimensRead Lyells’ Principles of Geology
8. 15. 2 Darwin’s Theory of EvolutionGeology and Fossils: Charles Lyell’s Principles of Geology( a book written on the ideas of James Hutton, )Uniformitarianism: the idea that that extreme geological changes can be explained by slow , natural processes ( and not necessarily by the supernatural) Earth is formed from natural process of uplift and erosion that can be witnessed todaySediments formed by erosion form deposits of soil and rockThese deposits then can be changed into sedimentary rockThese deposits can be uplifted to the surface by geological activityThese process are continuous from the past until todayHow does this influence Darwin?
9. Natural Selection and AdaptationNatural Selection Proposed by Charles Darwin (also by Alfred R. Wallace) as the mechanism by which evolutionary change occurs.Components of Natural Selection:Organisms have inheritable variationsOrganisms compete for resourcesOrganisms differ in Reproductive SuccessOrganisms become adaptedThomas Malthus: a social economist who's writings greatly influenced Darwin’s development of the Theory of Natural SelectionHis Book: An Essay on the Principle of Populations (1838)
10. Natural Selection and AdaptationArtificial Selection: process by which breeders choose which traits to perpetuate, where they select the animals and plants that will reproduce.
11. Natural Selection and AdaptationOn the Origin of Species By DarwinHypothesis: today’s life forms are descended from a common ancestor and that natural selection is the mechanism by which species can change and new species can arise.Darwin took 20 years to publish his findings on natural selection. Why?Alfred Russell Wallace (1823-1913): Also came up with the idea that nature shapes speciesindependent of Darwin. Worked in Indonesia and Australia
12. Natural Selection and AdaptationNatural Selection Can be WitnessedThe Galapagos islandsPeter & Rosemary Grant and the Galapagos finchesTheir 20 years of data collection and study on Daphne Major provides evidence of changes in traits of ground finches due to changes in the environmentOther Examples:The Pepper Moths of industrialized Great BritainPresent Day Antibiotic Resistance
13. 15.3 Evidence for EvolutionFossil EvidenceBiogeographical EvidenceAnatomical EvidenceBiochemical Evidencewww.rci.rutgers.edu
14. The Fossil RecordArchaeopteryx and Tiktaalik roseae
15. Fossils in the whale evolution record
16. Biogeographical EvidenceBiogeography: the study of the range and geographic distributions of life-forms on the Earth.Exploration of South AmericaPatagonian HareGalapagos Islands Tortoises FinchesWhere geography separates continents, we might expect different mixes of plants and animals These differences provides evidence that variability in a single, ancestral population can lead to adaptation to different environments through forces of natural selection
17. 15.3 Evidence for EvolutionAnatomical EvidenceHomologous structuresAnalogous structuresVestigial structuresEmbryology
18. Studies of embryology shows common features of development among several class of vertebrates.These shared developmental features support shared ancestry.Vestigial organs are present in modern day organisms but have lost the function they once performed for ancestral species. Examples:Vestigial organs such as appendix in humans, vestigial tails, webbing between finger so humansThe presence of pelvic and rear limb bones in some snakes and whales.
19. Biochemical EvidenceDNA & RNACytochrome CIf the strongest evidence for Natural Selection can be seen in the artificial selection of dogs by humans, the strongest modern evidence in support of EVOLUTION is BIOCHEMICAL EVIDENCEProtein Clock Theory
20. Chapter SummaryBefore the 1800’s most people believed that species were a result of special creation and that organisms did not change nor did new species ariseEvolution was not proposed first by Darwin but was already an idea and that several scientific disciplines contributed to its formulation. Darwin proposed the means ( the mechanism) by which evolution COULD occur (later Mendel showed us how through genetics ). Darwin was influenced by James Hutton, Charles Lyell, Lamarck, Thomas Malthus, and Carolus Linnaeus. You should know how each of these past scientists contributed to evolutionary thought and the development of hypothesis of natural selection.Also, by his observations and collections aboard the HMS Beagle. Darwin used scientific method.You should know the components of Natural Selection, what each one means.You should know about artificial selection, adaptation, and examples of natural selection being witnessed. You should know the evidences of evolution
21. Mader, S.S. 2011. Biology, 10th ed. McGraw Hill Companies INC. NY pp.265-282Credits