INTRODUCTION
The early species in the genus Homo are part of an extant subfamily (Homininae) of the family Hominidae (hominids). Early Homo species lived during the Pliocene and Pleistocene Epochs, about 2.4 mya to about 0.8 mya. (The 0.8 mya cut-off date is a bit arbitrary and is intended to allow us to compare and contrast early Homo erectus with later Homo erectus.)
At least four early species in the genus Homo have been identified: Homo rudolfensis, Homo habilis, Homo ergaster, and early Homo erectus. Homo rudolfensis and Homo ergaster are not universally accepted; some researchers classify the former as Homo habilis and the latter as Homo erectus.
In comparison with the earlier and contemporary australopithecines, all early Homo species would be characterized as gracile. Some paleoanthropologists have suggested that the diversity of early Homo species represents an adaptive radiation.
Early Homo species lived in Africa, Asia and possibly Europe. Environmental changes involved a series of glaciations that changed the ratio of land:water, altered climatic patterns, altered vegetation patterns, and opened or closed land bridges among land masses.
One of the most significant physical changes in early Homo species was an increase in brain size. Post-cranial traits are essentially "modern-looking" in the early Homo species.
There is evidence of cultural developments
associated
with the early Homo species, particularly stone tool use, meat
use,
home bases and language. Evidence from Kenya of early fire use is
debated.
OBJECTIVES
Upon successful completion of this lab, students will
READINGS
Complete/review the readings prior to class.
ASSIGNMENT
Answers to the following exercises 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 in or outside of
class
time. Genus and species names must be written according to
biological
convention.
Question 2: List two specific differences in the crania of Homo rudolfensis [habilis] (Figures 10.2 and 10.3) and a gracile australopithecine (Figures 9.11 and 9.12). List two specific differences in the crania of Homo rudolfensis [habilis] (Figure 12.2) and a robust australopithecine (Figures 9.11 and 9.12). Which (gracile or robust) seems a more likely candidate for the Homo ancestor?
Question 3: Compare the proximal femora of an australopithecine (Figure 9.13), a modern human (Figure 9.13) and Homo ergaster [erectus] (Figure 10.10). To which is Homo ergaster [erectus] most similar and why?
Question 4: What are other physical differences between Homo ergaster [erectus] (Figure 10.10) and modern humans (Figure 4.15)? List at least three differences.
B. Examine the physical characteristics of the early
Homo skull casts provided in the lab. Complete the
morphological
comparison table on the answer sheet and identify the species each
fossil
represents.
C. Based on the information covered in lab and
lecture,
what do you think is the phylogenetic relationship between the
australopithecines
and the early Homo species?
REFERENCES
France, Diane
2004 Lab Manual and Workbook for Physical Anthropology (5th
edition).
Wadsworth, Belmont, CA.
Lewin, Roger and Robert Foley
2004 Principles
of Human Evolution (2nd edition). Blackwell Publishing, Oxford.