Evolution 4: Evidence for Evolution

  • It as a very overwhelmingly established that it is not a mere theory.

Fossil Record

  • Shows that a succession of organisms have populated Earth throughout a long time.

  • Transitional Fossils: Show evolutionary links between groups of organisms

    • ex. Tiktaalik: transition between fish/amphibians

Anatomical Record

  • Homologous Structures: similar characteristics but not necessarily same function

  • Analogous Structures: similar functions but structurally different and different development

  • Vestigial Organs/Structures: Remnants of old structures that have little to no function or a completely different function

    • Mutations accumulate and shrink these structures until maybe it might disappear completely

    • Ex. Human appendix, goosebumps

  • Comparative Embryology: Similar embryological development in closely related species (all embryo have similar structures at diff stages of development)

Molecular Record

  • All living things use DNA as genetic material, code used by all ribosomes is universal.

  • DNA Mapping and Protein Sequencing

  • Genome Sequencing

Artificial Selection

  • Can use variations in populations to create vastly different “breeds” and “varieties”

Biogeography

  • Organisms found in a certain part of the world are more closely related to other organisms in that same area.

Observed Evolution

  • Insecticide/drug resistance - survivors live and reproduce

  • Peppered Moth - “Industrial Melanism”, Dark vs Light Variants

    • Early 1800s, Late 1800s, Mid 1900s - Pollution levels different changing color of moth

Related Aside

  • Complexity Fallacy:

    • Evolution not goal oriented (“teleology”)

    • Survivors do not represent peak of perfection

    • Evolution is about present situation and adapting to it

  • Intelligent Design: The belief that life is too complex to have evolved without the intervention of an “intelligent designer”