INTRODUCTION

Because human origins and the course of human evolution were contingent upon previous events in non-human primate evolution, it is important that we understand the origins and development of non-human primates during the Cenozoic Era.  In order to understand and evaluate the fossil record of non-human primate evolution, we must first understand the morphological differences among different types of primates.  Therefore, this lab focuses on two main topics: primate comparative anatomy and morphology and fossil evidence of non-human primate evolution.
 

OBJECTIVES

Upon successful completion of this lab, students will

• understand and identify the anatomical differences between quadrupeds and bipeds.

• understand and identify the anatomical differences between primates and non-primate mammals.

• understand the anatomical differences among major primate groups.

• evaluate and identify primate skulls.

• understand the behavioral implications of skeletal anatomy.

• understand major events in non-human primate evolution.

• recognize the taxonomic designations of major groups of extinct primates.

• consider the phylogenetic relationships between extinct and extant non-human primates.

READINGS

Complete the readings prior to class.

• Lewin and Foley (2004) - Chapters 6, 7, 8
  

• France (2004) - Chapters 4, 5, 7, 8
  

BACKGROUND INFORMATION

The following summary considers the physical characteristics of living primates, concepts that were covered in Anth 125, Introduction to Biological Anthropology. Primates is an order of mammals that are characterized by the following derived traits.

Sensory Traits

• forward placed eyes
• eyes enclosed in bony bar or socket
• stereoscopic vision
• color vision
• enlarged eyes
• reliance on vision
• reduction of snout and olfaction
• enclosure of middle ear structures
• large brain relative to body size

Locomotor Traits


• prehensile hands and feet
• opposable thumb and big toe
• nails instead of claws on digits
• erect sitting position

Dental and Dietary Traits


• omnivorous
• 2-1-2-3 dental formula

Social-Reproductive Traits


• grooming
• long period of infant dependency, parental care, maturation
• decreased number of offspring per birth
• long life span
  

Habitat


• arboreal
• tropical

Other anatomical features have behavioral implications.  For example, the degree of sexual dimorphism is an indication of reproductive behavior; monogamous species exhibit minimal sexual dimorphism while polygamous species exhibit extreme sexual dimorphism.  Large, blade-like incisors usually indicate a frugivorous (fruit) diet while large molars with thick enamel indicate a folivorous (leaf) diet. 

ASSIGNMENT

Answers to all questions will be neatly written in pencil on the answer sheets provided in lab.  Exercises that do not require examination of skeletal specimens may be completedoutside of class time.

A.  Complete the quadruped vs. biped comparative anatomy table on the answer sheet, based on the information provided in France's Chapter 4.

B.  Based on the information in France's Chapter 4, study the four skeletal specimens (B1, B2, B3, B4) in the lab and identify each specimen as that of a quadruped or a biped.

E.  Based on the information covered in the required readings, study the four skeletal specimens (E1, E2, E3, E4) in the lab and identify each specimen by type of primate, as specifically as possible.
 
 

II. NON-HUMAN PRIMATE EVOLUTION

BACKGROUND INFORMATION

To provide temporal context, we must review those intervals of the geologic time scale related to primate origins and evolution.  Geologists divide the history of the earth into two time intervals.  The Crypotzoic ["hidden life"] Eon is the time period from the origins of the earth about 4.5 billion years ago to the explosion of life forms on earth about 0.57 billion (570 million) years ago.  The Phanerozoic ["visible life"] Eon is the time period from 0.57 billion years ago to the present; it is divided into three eras.  The Paleozoic ["ancient life"] Era is dated from 570 to 225 million years ago (mya) and saw the origins of new life forms like insects, vertebrates, fishes, amphibians and reptiles.  The Mesozoic ["middle life"] Era is dated from 225 to 65 mya and saw the origins of mammals, birds and flowering plants.  The Cenozoic ["recent life"] Era is the time period from 65 mya to the present that saw the adaptive radiation of mammals and the origin of the mammalian order Primates.  The Cenozoic Era is divided into seven epochs as summarized in the table below.  In this lab we are concerned with primate evolution during the Paleocene, Eocene, Oligocene and Miocene epochs.
 

In completing this lab assignment, remember that classification and phylogenetic placement of very early "primate" fossils are debated among paleoanthropologists.  Some researchers recognize Purgatorius sp. and other Plesiadapiforms as pre-primates or proto-primates (transitional forms), while other researchers consider them to be non-primate but closely related mammals (probably insectivores).  It is widely accepted, however, that the earliest primates evolved from an insectivore ancestor.

ASSIGNMENT

Answers to all questions will be neatly written in pencil on the answer sheets provided in lab.  Exercises that do not require examination of skeletal specimens may be completed outside of class time.

A.  What is your reaction to the "Missing Links" handout provided in class, especially Figures 10.17 and 10.18? What are the implications for the study of paleoanthropology?

C. Complete Exercise 8.1 in the France lab manual, excluding questions 1 through 4.  For questions 5, 7 and 8, list at least two traits. For question 10, list at least one trait.  For question 11, list at least two similarities and two differences.  For question 12, list at least four similarities.  For question 13, list at least three skeletal parts. In addition to the text, use the following figures to answer the questions:

REFERENCES

Lewin, Roger and Robert Foley
2004   Principles of Human Evolution (2nd edition). Blackwell Publishing, Oxford.

France, Diane
2004 Lab Manual and Workbook for Physical Anthropology (5th edition). Wadsworth, Belmont, CA.