1. Chapter 9 Geology and Primate Origins

2. How to Become a Fossil
Taphonomy: The study of what happens to the remains of an animal from the time of its death to the time of discovery
Burial
Geologic processes
Biological processes

3. How to Become a Fossil (cont’d)
Petrifaction
Trace Fossils

4. The Importance of Context
Stratigraphy
Strata
The principle of original horizontality
The principle of superposition
The principle of cross-cutting relationships
The principal of faunal succession

6. The Importance of Context (cont’d)
The Geologic Time Scale (GTS)
The earth is ~ 4.5 billion years old
Human and primate evolution spans the last 65 million years (Cenozoic Era)
The GTS is divided into Eras, Periods, and Epochs

7. How Old is It? Relative Dating Techniques Lithostratigraphy
study/description of rocks in stratigraphic deposits
Tephrostratigraphy
Use of volcanic deposits in stratigraphy
Biostratigraphy
Chemical techniques within sites

8. How Old is It? (cont’d) Calibrated Relative Dating Techniques
Geomagnetic Polarity
Normal vs. reverse polarity
The geomagnetic polarity time scale (GPTS)
Paleomagnetism
Sediments

9. How Old is It? (cont’d) Chronometric Dating Techniques
Radiometric dating
Potassium-argon dating
Argon-argon dating
Fission track dating
Cosmogenic radionuclide techniques
Uranium Series techniques

10. How Old is It? (cont’d) Chronometric Dating Techniques (cont’d)
Radiocarbon dating
Electron trap techniques
Thermoluminescence
Optically stimulated luminescence
Electron spin resonance

11. The Earth in the Cenozoic
Continents and Land Masses
200 MYA the earth was divided into two major land masses
Laurasia: present-day North America, Europe, and Asia
Gondwanaland: Africa, South America, Antarctica, and Australia/India

12. Climate Change and Early Primate Evolution
Changes in the Paleocene: The origin of primates?
Plesiadapiforms
Small brains
Prognathic face
Postorbital bar
Diastema
Why Primates?
Visual predation

15. Climate Change and Early Primate Evolution (cont’d)
True Primates of the Eocene
Adapoids
Omomyoids
Continental Drift
Strepsirhine-Haplorhine
Split

16. Adapoids and Omomyoids
From around 54 mya, in the early Eocene
Two forms of primates emerged: Adapoids , the ancestors of Strepsirhines , and Omomyoids , ancestors of Haplorhines .
Adapoids – some nocturnal, some diurnal.
Small ounces to 15 lbs.

17. Adapoid

18. Omomyoids Perhaps as far back as 60 million years ago.
Large diversity.

19. CLIMATE CHANGE AND THE ORIGIN OF MONKEYS AND APES
The First Monkeys?
New World Monkeys
Old World Monkeys
What favored the origin of anthropoids?
The earliest apes

20. Climate Change and Early Primate Evolution
Selection Pressures and the Divergence of Monkeys and Apes
Evolution of brachiation
Middle Miocene forests
Dental evidence - a dietary shift

21. Climate Change and Early Primate Evolution (cont’d)
The Monkey Tale: What Happened to Primate Diversity in the Miocene?
Changing environments
r-selected vs. k-selected

22. Molecular Evolution in Primates
Molecular phylogeny: a tree of relatedness among taxonomic groups based on a gene or protein
Molecular clock
Calibrated
Rate consistency