Name: _____________________________________
Chapter 4: Life Changes Over Time
Terms to know:
 Adaptation: trait that helps an organism survive in its
 Amber: hardened tree sap
 Anthropology: science that deals with the study of human beings
 Evolution: process by which species change over time
 Extinct: no longer found as a living species
 Extinction: disappearance of all members of a species
 Fossil: remains or traces of a once living organism. Found in
sedimentary rock.
 Homologous structures: body parts that have the same basic
 Mutation: sudden change in a gene
 Natural selection: survival of offspring that have favorable traits
 Overproduction: the idea that a species produces more offspring
than can survive.
 Species: group of organisms that look alike and can reproduce
among themselves.
 Variation: differences in traits among individuals of a species
 Vestigial structures: body parts that seem to have no function
Other things ~
 Human activities affect other organisms with pollution. (Think of the Moths)
 We belong to the species Homo sapiens.
 The humanlike fossil called Lucy is 3.5 million years old.
 The horse has the most complete fossil record of evolutionary change.
Think about this…
Would species have evolved over time if the environments they lived in never
changed? Explain your reasoning.
Use the Chart to answer the following questions.
1. Which of the Homo sapiens lived from 130,000 to 35,000 years ago?
2. How long ago did Homo habilis live on Earth?
*A little over a million years
3. About how long did Homo erectus inhabit Earth?
*a little more than 1 million years
4. How much longer than Homo habilis did Homo erectus inhabit Earth?
* ½ million years
5. Which of the ancestors of modern humans inhabited Earth for the longest time?
* Australopithecus Afarensis