Principles of Evolution and the History of the Idea

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Principles of Evolution and the History of the
Idea

• BIOL 100
• 10 November 2009

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The Origin of the Concept of Evolution

• Darwin
• Erasmus Darwin
• (Grandfather of Charles)
• b. 1731, d. 1802
• London-area physician
• Naturalist
• Inventor
• Poet

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Jean Baptiste Lamarck

• b. 1744, d. 1829
• Wrote Philosophie Zoologique (1809)
• Included chapter on evolutionary change over
  generations
• Use and disuse
• Giraffe necks
• Egret legs
• Blacksmith children
• Lost legs of snakes

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Robert Chambers

• Scottish pamphleteer
• Anonymous author of Vestiges of the Natural
  History of Creation (1845)
• Theological view of evolutionary change over time
  in living organisms

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Charles Robert Darwin

• b. 1809
• Father Robert Darwin, a London-area physician
• College medicine (Edinburgh), then theology
  (Cambridge)
• 1831-1836 voyage on the H.M.S. Beagle, on a
  mapping expedition in South America and various
  oceanic island groups

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Voyage of the H.M.S. Beagle
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John Stevens Henslow

• Darwins professor at Cambridge (botanist,
  zoologist, geologist, paleontologist, etc.)
• Suggested him for the post
• Corresponded with Darwin and received his
  specimens during the voyage

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Darwin Timeline

• 1836Return to England
• 1837Marriage and retreat to Downe
• Opens first private notebook on
• the species question
• 1838Eureka Moment while reading
• Thomas Malthus essay On Population (1798)

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Malthus and the Idea forNatural Selection

• Malthus main point Human populations grow more
  rapidly than does their capacity to feed
  themselves
• Darwins four observations
• a) Organisms vary
• b) Variation is inherited
• c) Some variation is more beneficial to survival
  and reproduction than other variations
• d) All organisms produce more offspring than the
  environment can support

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Darwins Struggle for Existence

• Determination of which variants survive, in the
  face of the death made necessary by environmental
  limitations on population growth
• Philosopher Herbert Spencer Survival of the
  Fittest

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Three Key Observations on the Voyage Relating to
Evolution

• Fossils (esp. giant armadillos)
• Replacement by similar species across South
  America
• Unique animals and plants of the Galapagos
  Islands and their variation

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Darwin Timeline

• 1842First draft of theory (35 pp.)
• 1844Second draft (230 pp.)
• Shared second draft with eminent geologist Sir
  Charles Lyell and botanist Joseph Hooker

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Darwin Timeline

• 1846-185410 volumes on barnacle taxonomy
• 1856Lyell and Hooker convince Darwin to start
  big book
• To be 1500 pp.

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Alfred Russel Wallace

• b. 1823, d. 1913
• Amazon expedition, 1848-1852
• Southeast Asian islands expedition, 1854-1862
• Sent Darwin a manuscript in 1858

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Wallaces 1858 Manuscript

• Briefly outlined the concept of evolution by
  natural selection
• Wallace asked Darwin to forward the ms. to Lyell
• After consultation with Lyell and Hooker, the ms.
  and a letter of Darwins were both read at a
  scientific society meeting
• 1859 Publication of Origin of Species
• Just 500 pages