CHAPTER 13: THE ENVIRONMENT AND CHANGE OVER TIME

Lesson 1: FOSSIL EVIDENCE OF EVOLUTION

?? Essential Questions How do fossils form? How do scientists date fossils? How are fossils evidence of biological evolution?

Vocabulary Fossil Record Geologic Time Scale Mold Extinction Cast Biological Evolution Trace Fossil

The Fossil Record The fossil record is made up of all the fossils ever discovered on Earth

Fossil Formation Only the dead animal’s hard part, such as bones, shells, and teeth, remain Mineralization Minerals replace the organism’s original material and harden into a rock

Fossil Formation Carbonization Molds and Casts When a dead organism is compressed over time and pressure drives off the organism’s liquid and gases Molds and Casts The impression of an organism in a rock is called a mold A cast is a fossil copy of an organism in a rock

Fossil Formation Trace Fossils Original Material A trace fossil is the preserved evidence of the activity of an organism Original Material

Determining a Fossil’s Age Relative-Age Dating Absolute-Age Dating

Fossils over Time The Geologic Time Scale Dividing Time The geologic time scale is a chart that divides Earth’s history into different time units Dividing Time

Extinctions Extinctions occurs when the last individual organism of a species dies Environmental Change Sudden Changes Gradual Changes Extinctions and Evolution Biological evolution is the change over time in populations of related organisms

Classwork Page 468 #1-9 Write down questions and answers Workbook page 410 - 412