Evidence of Evolution

The Scientific Process:

    Generating hypothesis for Evolutionary Change:

  • H1: (Null): Evolution doesn’t occur

  • H2: No change within or connection among lineages, but extinction occurs

  • H#: Extinction occurs, lineages change over time, but no common descent

  • H4: Extinction occurs, lineages change over time, and common decent


Evidence for evolution:

  1. The Fossil Record

    • Extinction

    • Principle of Faunal Succession (Law of Succession)

    • Transitional forms

  2. Homology

    • Vestigial Traits

  3. The Age of the Earth- old enough!

  4. Direct Observation


George Cuvier: Father of Paleontology

  • Established the field of palentology

  • Formalized the fossil record


Mary Anning

  • Greatest fossilist the world ever knew

  • Discovered many jurrassic fossils

  • Not acknoledged for many of her finds

  • Contributed evidence that supported extinction events


Estimating the age of fossils:

  • Relative dating

    • Law of Superposition: The oldest layers are at the bottom

  • Absolute dating

    • Radiocarbon dating: ratio of isotopes indicated how long ago something lived, if you died recently youll have a lot more carb 13s,


The Principle of Faunal Succession

  • Fossils are more similar to:

    • other fossils in adjacent rock layers (above & below them)

    • living organisms in same geographic location

  • Indicated that lineages (organisms in a given location) are changing over time


Homologous Traits → inherited from common ancestor

  • Same underlying bones

  • Molecular homology- evidence in the genome

Hidden homology→ VESTIGIAL TRAITS

  • Trait that was in the ancestor now functionless