ANT203Y5 – BiologicalAnthropology
Lecture 26 – February 27, 2014
Paleoanthropology: An Introduction
- Different fossils, where they are, many classifications of fossils and questions of fossil hunters.
What is Paleoanthropology?
- Paleoanthropology can be defined as the study of early humans. It is important to
mention that this comprises both their biology and their culture.
- Scientists from many disciplines join their efforts to obtain the most complete perspective
of human origins possible….
- Biological anthropologists, archeologists, paleontologists, paleobotanists, and geologists,
among many others.
Windows into our Past…
- Important clues about the evolution of our species can be obtained by analyzing fossil
- Here is some more information about fossils and how they form…
- Fossilization is a rare phenomenon, and it is dependent of a number of important factors
affecting preservation after death, including….
- Geological factors: Nature and composition of sediments.
- Temporal factors: Variation of preservation conditions through time.
- Biological factors: Role of organisms after death
- *Taphonomy is the study of the processes affecting an organism after death that result in
- Plants and animals from humid tropical forests, or mountain areas are rarely preserved
due to high rates of decay or erosion.
- This is one of the reasons for the lack of fossils for the chimp or gorilla lineages.
- Also, hard parts (bones, teeth) of the body tend to be preserved, while soft parts are
- Most of the hominid fossils have been found in:
o Volcanic deposits.
o Lake (lacustrine) or river (fluviatile) sediments.
The Fossilization Process
- There are several ways in which fossilization can occur. Below, we indicate three
o Organic or inorganic material is replaced by soil minerals (e.g. calcium
carbonate, calcium phosphate).
o “The Black skull” - Early robust estrolopithises (ehtiopia). The black skull name
comes the black and blue color of the skull because of the skull preserved in soil
- Cast and mold ANT203Y5 – BiologicalAnthropology
Lecture 26 – February 27, 2014
o Caused by deposits of sediment in cavities of the organism, resulting in a three
o The Taung Child –Estolopithicus Africanus; discovered by Raymond Darke.
When he saw this fossil in S.Africa, the skull was primate like, whereas the face
was human like.
o Two-dimensional imprints most commonly found in silt or clay, without organic
o Litalie footprints: are around 3 million years ago. We know that hominids were
walking bipedially as far back as 3.6 million years ago
Dating the Fossils
- Finding a fossil (lucky you!) is just the first step of a long process, and there are many
other things to do.
- The next key step is to determine the age of the fossil. This is critical to put together the
complicate puzzle of human evolution
- Two main categories:
- Relative methods: They give the time of a fossil or artifact with reference to another
fossil, artifact, or event. They don’t provide absolute dates.
- Chronometric (or absolute) methods: They provide estimates of the actual age of the
Relative Dating Methods
- Stratigraphic dating: Based on the geological principle of superposition: The deeper the
layers of deposits, the older.
- Problems with Stratigraphic Dating
o Method is only relative.
o Not valid for sites with different stratigraphy.
o Possible problems due to disturbance of the layers (for geological reasons, or
human or animal action)
- Based on chemical changes of skeletal remains buried in the earth
- Fluorine is an element that is found in ground waters
- With time, the amount of fluorine in the bone increases (and the amount of nitrogen
- Problems with Fluorine Analysis
o Relative method doesn’t provide absolute dates.
o Difficult to compare bones from different sites, because fluorine content can