INTRODUCTION

Biological classification is the process of identifying and naming unique forms of life and describing the relationships among different forms of life.  The system of biological classification used by most scientists is the Linnaean system, which was developed primarily on the basis of morphology and has species as its basic unit of comparison.  Biological classification is done with both living (extant) and extinct life forms.  Though Linnaeus' original system did not consider it, phylogeny or evolutionary relationships are often incorporated into biological classifications today.  Further, today scientists use traits such as genetic makeup and fossils in addition to morphology in order to classify life forms (France 2004).

As explained by France (2004:48-49), the "phylogenetic approach to classification is divided into two schools: cladistics and evolutionary classification. Cladistic classification (cladism) is based exclusively on genealogy, that is, a genus should include a group of species that all descended from the same common ancestor.  Cladistic classification is also usually focused on more recently shared characters, or 'derived' characters.  ...  On the other hand, while evolutionary classification is the same as cladism in that it is based on evolutionary history, it also takes into account the time factor, and the different rates of evolution in different lineages."

The traditional biological classification of the order Primates recognizes two major groups: prosimians and anthropoids.  Anthropoids include monkeys and apes (hominoids).  The hominoids are further subdivided into lesser apes, great apes, and humans (hominids).

OBJECTIVES

• to review the fundamental principles of biological classification

• to understand the fundamental principles of phylogeny

• to review the major taxa in primate classification

Read Chapter 2 in France (2004) and Chapter 3 in Lewin and Foley (2004).

TERMS

• biological classification
• taxonomy
• Linnaean system
• morphology
• taxa / taxon
• species
• paleospecies
• genus / genera
• extinct
• extant
• homology
• analogy
• derived traits
• primitive (ancestral) traits
• clade
• cladistics (cladism)
• evolutionary classification
• primates
• prosimian
• anthropoid
• hominoid
• hominid

Complete all questions in Exercise 2.1 on the answer sheet provided by the instructor.

For question 2, focus on the Hominoidea differences.

For question 7, your answer should include biological/physical traits, not behavioral/cultural traits.

For question 9, refer to the handout provided by the instructor.  Add a brief explanation of why you think the classification is cladistic or evolutionary.

Answer these two additional questions:

15.  When developing a phylogenetic classification, how many traits do you think should be used minimally (i.e., what is a sufficient number of traits)?  Why?  How should scientists select these traits (i.e., which traits would be most/least helpful)?  Why?  Should some traits be considered more important than others?  Why or why not?

16.  In what ways are the concepts covered in this lab relevant to the field of paleoanthropology?  In other words, list reasons why you've been asked to complete this lab assignment for Anth 375.

REFERENCE

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