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9/27/2012

History of Evolutionary Thought and • Argument from Authority – Reality can be explained by scripture or by persons • Methodological to explain nature – Supernatural explanations are not allowed

Aristotle (384-322 B.C.E.) Rise and Fall: in a nutshell ’s student Studied , , and • Greeks used methodological naturalism Continued Plato’s idea of eidos Concept of eidos for persisted until • After, and scripture used for Darwin

• Methodological naturalism rejected – not entirely • 18th century: – Search for laws

Age of the Earth (1797-1875)

• Greeks: eternal • (1830) • scholars: ~ 5000 years • Based on • George Buffon (1707 – 1788), French naturalist • Was the geology textbook of – 75K to 2-3M years – Used Darwin’s day • (1726-1797), Scottish • Friend of Darwin – Founder of modern geology – Earth is incredibly old – Uniformitarianism

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Natural History and Classification Organisms and their environment

• Aristotle proposed a simple • William Paley (1743-1805) Natural classification with and – God as Watchmaker species • are impossible • Scala naturae: – Lewis and Clark • Karl von Linne (, 1707-1778) • (1769-1832), French – Binomial – Father of – Extinctions are real – Was all about sex!

Change through time Change through time

• Greeks proposed it • Robert Chambers • Bible scholars forbid it – Vestiges of the of Creation (1845) – Organisms created perfectly – Organisms evolve – Immutability of species – Process is slow • (1731 – 1802) – Emphasis on populations – ’s grandfather • Jean-Bapiste Lamarck (1744-1829) – Zoonomia (poem) – Zoological Philosophy (1809) – Organisms evolve in scala naturae – Inheritance of acquired characteristics – Publically ridiculed

Change through time Along came Darwin 1809—1882

• Grandfather and father were doctors • Went to Edinburgh for two semesters to study medicine – dropped out • Went to Christ’s College to be a clergyman – Studied natural theology: geology and natural history – Energetic field student – Urged to go aboard the HMS Beagle – The captain (Robert FitzRoy) needed a companion of similar social stature

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Voyage of the HMS Beagle Voyage of the Beagle

• Surveying trip – Map coastlines – Test new equipment • Naturalist on board was the doctor • Was supposed to be three year journey – went 5 • Left 1831, Darwin age 22 • Went to Azores, S. America, Galapagos, Australia, Tahiti

Voyage of the HMS Beagle Voyage of the HMS Beagle

• Darwin collected and living organisms • Observations • Ship’s official naturalist left – Each Galapagos island had its own , mockingbird • Darwin shipped materials back – species similar but • Became famous as a naturalist not the same as extant • Wrote several books soon after species – Similar species over land masses – • Thomas Malthus

Darwin, from boat to book (1823-1913)

• After the Beagle trip, married and settled in • Studied butterflies in the country • Knew many of the same • Studied , , seeds as Darwin • Researched like mad • Sent Darwin an outline of in 1855 • Did not work for a living • In 1858, co-authored a – Married cousin, invested, inheritance paper with Darwin on natural selection • Thought about natural selection and evolution • Not a big hit • Thousands of letters of correspondance

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Origin of Origin Natural selection sensu Darwin

• Happens when • Inspired by Wallace, finally published his draft On – More organisms are born than can survive and the Origin of Species by Means of Natural reproduce Selection, or the Preservation of Favoured Races • Competition to represent the next generation in the Struggle for in 1859 – Those organisms more likely to survive because of • Stressed the importance of variation within a some trait will leave more offspring species – If that trait is heritable then the offspring will have • Natural selection that trait • Common ancestry: hierarchical branching – If conditions continue then that trait will spread in – reflects ancestry the population

Process related to artificial selection Major Darwinian Ideas

• Natural selection • Common ancestry

Interspecific variation There are fitness consequences to this variation • Organisms vary within a species

Male tail streamers length as a predictor of reproductive success: (a) First brood breeding success, (b) Annual breeding success, (c) Successful genetic offspring in first brood, and (d) Annual genetic breeding success. Vortman Y et al. Behavioral Ecology 2011;beheco.arr139

© The Author 2011. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved. For permissions, please e-mail: [email protected]

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The variation is heritable Natural selection occurs

Dave Reznick

Caribbean Anoles Common Ancestry

• Phylogenetic trees

Pre-Darwinian Linnean classification Post-Darwinian Classification

Species Species Species Species Species Species Species A B E F Species D A E D Genus G Genus C Common Ancestor C Common Species Species Ancestor G B F H Common Ancestor H

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Phylogenetics and Taxonomy Reception of Origin

• Pre-Darwinian Taxonomy • Most scientist accepted evolution –Classification arbitrary • Natural selection not as widely accepted • Post-Darwinian Taxonomy –Classification represents lineages – = monophyletic group • Taxonomy should reflect phylogeny

Issues with Darwin To recap

• Eusocial • Darwin’s contributions • Mechanism of heredity unknown – Evidence that evolution happened • Time – Mechanism of evolution: natural selection – Pattern of evolution: heirarchical

Rise of the Geneticists

• Weisman's germplasm hypotheses • Early Geneticists – Contra Lamarck – Variation was discrete • Hugo DeVries – produced large changes – worked with mutations • Naturalists – genes – Most variation was continuous

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Population Genetics

• Resolved the dispute between naturalists and • Evolution is geneticists – Descent with modification • Modern Synthesis of 1940’s – Change in gene frequency – Ronald Fisher – Theodosius Dobzhansky – Sewall Wright – JBS Haldane – Ernst Mayr – George Simpson

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