THEORY OF EVOLUTION

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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. b. layer most likely to contain fossils. c. oldest. d. Both (a) and (b)
THEORY OF EVOLUTION Section 15-3: Evolution in Action Read the passage below, which covers topics from your textbook. Answer the questions that follow. The change of two or more species in close association with each other is called co evolution. Predators and their prey sometimes co evolve, parasites and their hosts often co evolve, and plant eating animals and the plants they feed on also co evolve. One example of co evolution is plants and the animals that pollinate them. Sometimes, organisms that appear to be very similar, such as a shark and a porpoise, are not closely related at all. This kind of similarity is the result of convergent evolution. Convergent evolution occurs when the environment selects similar phenotypes, even though the ancestral types were quite different from each other. Analogous structures, such as similar fins in very different animals, are associated with convergent evolution. In divergent evolution, two or more closely related populations or species become more and more dissimilar. Divergence is nearly always a response to differing environments, and it can ultimately result in new species. Sometimes, the process of divergence can be sped up artificially through artificial selection. All domestic dogs are the same species, Canis familiaris. Dogs have been bred by humans for certain phenotypic characteristics, resulting in different breeds with different traits. Refer to the passage to complete the graphic organizer below. SKILL: Organizing Information Patterns of Evolution Evolution Pattern Example 1. 3. Parasites & their hosts Convergent evolution 4. 5. 2. 2 or more related species 6. or populations become more and more dissimilar, often due to differing habitats P Circle the letter of the word or phrase that best completes the sentence. 7. Artificial selection can sometimes speed up the process of a. convergent evolution. b. co evolution. c. divergent evolution. d. Both (a) and (b)erns of Ev
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THEORY OF EVOLUTION

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