Chapter 16, Problem 12A

Summary Introduction

To define:

The given vocabulary term

Introduction:

The lineage that led to humans split off from the other African apes occurred sometime between 8 and 5 mya. Hominins include humans and all their extinct relatives. The evolutionary changes in hominoids led to bipedalism in hominins. The earliest fossils of species that show some degree of bipedalism are 6- 7 million years old.

Answer to Problem 12A

Australopithecines are the hominins that lived in in east- central and southern part of Africa between 4.2 and 1 mya and had apelike brains and jaws.

Explanation of Solution

An anthropologist Donald Johanson discovered an australopithecine skeleton named Lucy in Kenya in1974. The first hominins that were truly bipedal were the australopithecines.

The discovery of fossil of Lucy is very significant as it was the first complete australopithecine fossil to be discovered. She was a member of species A.afarensis which lived between 4 and 2.9 mya. Lucy was about the size of a chimpanzee and had a typical australopithecine skull and small brain. The structure of her skeleton suggested that A.afarensis had small brains and were bipedal.