Scientists Evolution Timeline

  • George-Louis Leclerc de Buffon

    • a French naturalist
    • rejected that organisms arose separately
    • proposed that species shared ancestors based on evidence of past life on Earth
    • also rejected that Earth was only 6,000 years old and thought it was much older (agreed with Charles Lyell
  • Erasmus Darwin

    • Charles Darwin's grandfather and was a doctor and poet
    • proposed that all living things were descended from a common ancestor
    • also proposed that more-complex forms of life arose from less-complex forms
  • Carolus Linnaeus

    • a botanist developed a classification system for all types of organisms
    • the classification system was used to group organisms by their similarities. it reflects evolutionary relationships and is still used today
    • abandoned the common belief that organisms were fixed and did not change
    • proposed that some might have arisen through hybridization
  • George Cuvier

    • French zoologist
    • didn't think species could change or become extinct
    • observed stratum and held/found fossils
    • theory of catastrophism: states that natural disasters such as floods and volcanic eruptions happened often during Earth's long history which shaped landforms and caused species to become extinct in the process
  • James Hutton

    • Scottish geologist
    • proposed gradualism: changes observed in landforms from slow changes over a long period of time
    • laying down of soil pr the creation of canyons by river cutting through the rock was not the result of large-scale events
    • resulted from slow processes that happened in the past
    • the term gradualism is often used to mean the gradual change of a species through evolution
  • Thomas Malthus

    • published a book called "An Essay on the Principle of Population" -came up with the theory that through preventative checks and positive checks, the population would be controlled to balance the food supply with the population level -noticed humans had a propensity to utilize abundance for population growth rather than for maintaining a high standard of living
  • Jean-Baptiste Lamarck

    • proposed all organisms evolved toward complexity; didn't think species went extinct/ instead evolved into other organisms
    • changes in environment caused organism's behavior to change, leading to greater use/ disuse of structure (inheritance of acquired characteristics)
    • knew 2 key things to evolutionary theory: new physical forms/ traits have emerged due to environmental changes; these traits appeared in subsequent generations
    • Neo-Lamarckism: IOAC; only occurs through epigenetics
  • Charles Lyell

    • English Geologist
    • published Principles of Geology
    • expanded Hutton's theory of gradualism into the theory of uniformitarianism: states that the geologic processes that shape Earth are uniform through time
  • Ernest Haeckel

    • proposed the idea that all multicellular animals derived from a theoretical two-layered animal called the Gastraea
    • was the first to divide the animal kingdom into unicellular and multicellular animals
    • best known for inventing many terms that biologists use today such as phylum, phylogeny, and ecology
  • Charles Darwin

    • observed differences in appearance among island species
    • concluded that species may be able to adapt to their surroundings
    • also observed fossil and geologic evidence supporting an ancient Earth
    • found lots of fossils which gave him evidence that species changed over time
  • Alfred Russel Wallace

    • best known for independently conceiving the theory of evolution through natural selection
    • his work was jointly published along Charle's Darwins in 1858
    • came to understand how species evolved- they changed because the fittest individuals survived and reproduced, passing their advantageous characteristics onto their offspring
  • E.J. Steele

    • hypothesized the RNA/ RT-based mechanism of somatic hypermutation
    • this proved the first mechanism to explain neo-Lamarckism
    • he also combined Darwin and Lamarck's works in a way to create meta-Lamarckism