Review Questions

1st Lecture Test

Earth History and Global Change

GEOL-1122   Spring 2015

 

Section #1 - Introduction

1) Define Historical Geology.  How does it differ from Physical Geology?

2) Name and describe different types of events that Historical Geology attempts to recognize and correlate.  List and describe the geologic data that is used to recognize these events.

3) Explain why understanding the geologic past is beneficial and important to society and future generations.

 

Section #2 ‑ Geologic Time

 Readings ‑ Chapter 17 (Geologic Time: Concepts and Principles)

1) Name and describe the earliest types of time-keeping devices.  Describe how the invention and use of these devices changed social behavior. 

2) How do infants and most animals other than humans perceive time and the past?  Define deep time. Give examples and explain why certain theories in biology and/or astronomy are dependent on the modern view of geologic or deep time.    

3) Why did early societies believe that time was cyclic and events were repeated?  When and why was linear time proposed and accepted? 

4) Describe how James Ussher determined that the earth was 6,000 years old.  How did Lord Kelvin determine a much older age for the earth?  Describe two other methods involving geologic processes that were used to determine an age for the earth.  Why did these age estimates differ so much?  How do these dates compare to Ussher's age? 

5) Why is the currently proposed age for the earth based on  moon-rocks and meteorites?  What is this age?  Why does the moon's surface record a much older and different geologic history than the earth's surface if they are both similar in age? 

6) Define, compare and contrast relative and absolute age dating.  How is each type obtained?

7) Define stratigraphy.  Describe the following principles of stratigraphy: lateral continuity, horizontality, superposition, cross‑cutting relationships, and principle of inclusions.

How are these principles used to decipher the geologic rock record?  Which type of age data (relative or absolute) can be obtained from the application of these principles.   

8) What is seismic stratigraphy?  Why is this technique commonly used in oceanic areas to study subsurface geology?

9) What is a key (marker) bed?  Why are marker beds so useful in correlating and mapping rock units?  Name a rock type that would make a good key or marker bed in a thick sequence of sandstone, shale and limestone.  Name a rock type that would make a good key or marker bed in a sequence of lava flows and tuffs.

10) Name and describe the similarities and differences in the geologic histories of the three types of unconformities.  Make a simple sketch of each type of unconformity.  

11) What is the Law of Fossil Succession?  Describe how biostratigraphy is used to determine relative rock ages. 

12) What is a guide (index) fossil?  What are the important characteristics of a guide fossil?  Why are fossil assemblages more accurate than single guide fossils?

13) Describe how radioactive decay is used in radiometric dating.  What are the important characteristics of radioactive decay that allow it be used as a geologic clock?  Which rock types can be dated by radiometric techniques?  Be able to calculate geologic ages based                on isotopic abundance and/or percentages of parent and daughter material and reported half‑lives. (See your homework exercises for this question.) Compare and contrast the following types of radioactive decay: alpha decay, beta decay, and electron capture.

14) What are the names and basis for the three major subdivisions of geologic time

15) Define the following terms: fossil, lithostratigraphy, formation, isotope, Carbon-14, tree-ring dating, Precambrian, Paleozoic, Mesozoic, and Cenozoic.

 

Section #3 ‑ Evolution and the Fossil Record

  Readings: Chapter 18 (Fossils and Evolution)

1) Describe the optimal conditions for fossilization.  Describe the different types of information that can be derived from fossils. Why is preservation in anoxic sedimentary environments more common?

2) Why is the fossil record biased?  List and describe the major biasing factors.  Next, list and describe ways in which the fossil record still supports the theory of evolution.

3) List the major groupings (taxonomic classifications) of life forms.  How are different genus and species recognized and defined?  How are fossils classified?  What are some of the problems with this classification?

4) What is Lamarckism?  What was the proposed mechanism responsible for the change?

5) How did Darwin's study of finches on the Galapagos serve as evidence for evolution?

6) What is Natural Selection?  Describe the observations on which this theory is based.  Describe how the theory has been misinterpreted by certain political groups.  Describe how Gregor Mendel's work provided a valid mechanism for natural selection.  How does artificial selection differ from natural selection?

7) How are paleobiogeography studies used in support of evolution?  Describe the other major lines of evidence in the fossil record that support the idea of evolution?

8) Describe how both genetic recombination and mutations are the sources for variation within a population.  What are some causes of increased mutation rates?

9) Compare and contrast convergent and divergent evolution.  Give examples of both.

10) What is speciation?  What are some possible isolating barriers that might cause speciation?

11) Compare and contrast gradualism and punctuated equilibrium. Describe how both are represented in the fossil record?  What are the most likely causes of each? 

12) What is extinction?  What are some of the possible causes?

13) Define the following terms: genetics, spontaneous generation, atavism, chromosomes, mutation, vestigial organ, cladogram, analogous structures, and mass extinction.

14) What are homologous structures?  Describe why the different limbs shown below are considered homologous organs.  Which of these are also analogous?  Explain.