Active Reading Worksheets s2

Name______Class______Date______CHAPTER 15 ACTIVE READING WORKSHEETS THEORY OF EVOLUTION

Section 15-2: Evidence of Evolution

Read the passage below, which covers topics from your textbook. Answer the questions that follow.

In 1668, Robert Hooke published his conclusion that fossils are the remains of plants and animals. Hooke was one of the first scientists to study fossils, principally petrified wood, with the aid of a microscope. Hooke thought the detail he saw with the microscope was too fine and precise to have been formed by the rock itself. He hypothesized that living organisms had somehow been turned to rock. Hooke’s view was shared by another scientist of his time, Nicolaus Steno. In 1669, Steno proposed the principle of superposition, which states that successive layers of rock or soil were deposited on top of one another by wind or water. The lowest stratum, or layer, in a cross section of Earth is the oldest, while the top stratum is the most recent. Thus, fossils within a single stratum are of the same approximate age. Using Steno’s principle, observers could establish the relative age of a fossil; that is, they could say that a given fossil was younger or older than another fossil. The fossil’s absolute age (its age in years) could be estimated from the amount of sediment deposited above the fossil or by using the radiometric dating of a nearby rock layer.

Fill in the blank to complete each sentence.

SKILL: Sentence Completion

One reading skill is the ability to complete an incomplete sentence by logically determining what will complete the unfinished thought. 1. Robert Hooke was one of the first scientists to study fossils through a ______. 2. His observations led Hooke to conclude that fossils are the remains of ______. 3. According to the principle of superposition, fossils in the same stratum are about ______.

Circle the letter of the word or phrase that best completes the statement. 4. The top stratum in a cross section of Earth is the a. youngest. c. oldest. b. layer most likely to contain fossils. d. Both (a) and (b)