Transcript Part 2

Part 2 Evolution
The Challenge of
Understanding Human
Origins
Part Outline
Chapter 4 Field Methods in Archaeology
and Paleoanthropology
 Chapter 5 Macroevolution and the Early
Primates
 Chapter 6 The First Bipeds

Chapter 4
Field Methods in
Archaeology and
Paleoanthropology
Chapter Outline
How Are the Physical and Cultural
Remains of Past Humans Investigated?
 Are Human Physical and Cultural
Remains Always Found Together?
 How Are Archaeological or Fossil
Remains Dated?

Artifacts
Express facts of human culture:
 What people do with the things they
have made.
 How they dispose of them.
 How they lose them.
The Nature of Fossils
A trace or impression of an organism of
past geologic time preserved in the
earth’s crust.
 Involves the hard parts of an organism:
bones, teeth, shells, horns, and the
woody tissues of plants.

How Organisms Are
Preserved
Frozen in ice like the famous
mammoths found in Siberia.
 Enclosed in a fossil resin such as amber.
 Preserved in lake bottoms and sea
basins where accumulated chemicals
create an antiseptic environment.
 Mummified in tar pits, peat, oil, or
asphalt bogs.

Locating Sites: Clues
Irregularities of the ground surface.
 Unusual soil discoloration.
 Unexpected variations in vegetation
type and coloring.
 Ethnohistorical data - maps,
documents, and folklore.

Finding Clues

The plan of an ancient posthole pattern and
depression at Snaketown, Arizona—permits
reconstruction of the hypothetical house.
Methods for Dating
Remains
Relative dating - determines the age of
objects relative to one another.
 Chronometric dating - determines the
absolute age of an object.

Prehistoric Pottery
Decoration

Coastal people twisted fibers used to make
cordage to the left (Z-twist), while those living
inland did the opposite (S-twist).
Methods of Chronometric
Dating
Radiocarbon analysis - measures
carbon 14 that remains in organic
objects.
 Potassium-argon analysis measures radioactive potassium that
has decayed to argon in volcanic
material.

Methods of Chronometric
Dating
Dendrochronology - based upon tree
rings.
 Amino acid racemization - based on
changes from left to right-handed
amino acids in organic materials.
