Anthro

Paleoanthropology and Fossilization

• Paleoanthropology: A subfield of biological anthropology focusing on human evolution.

• Taphonomy: The study of what happens to an organism after death until its discovery.

  • Stages after death:

    • Death

    • Burial in low oxygen environments

    • Decay/Decomposition

    • Fossilization

    • Discovery

Stratigraphy

• Stratigraphy: The study of rock layers (strata) and how they form.

  1. Original Horizontality: Layers are deposited horizontally.

  2. Superposition: Older layers are lower in the strata; younger layers are higher.

  3. Cross-Cutting Relationships: Features that cut across strata are younger than the layers they cut through.

  4. Faunal Succession: Fossil organisms appear in a predictable vertical order.

  5. Uniformitarianism: The same natural laws and processes in operation today have always operated in the past.

Dating Techniques

• Relative Dating: Places fossils in a sequence (younger or older based on stratigraphy).

  • Biostratigraphy: Compare fossils to known species.

  • Fluorine Dating: Bones absorb fluorine in the soil; older bones have more fluorine.

  • Paleomagnetic Dating: Based on the history of Earth's magnetic field inversions.

• Chronometric Dating: Provides actual numeric ages.

  • Radiometric Methods:

    • Carbon-14 Dating: Up to about 50,000 years.