CHAPTER 8 QUESTIONS
University of California , Berkeley, has a nice history of life web site …. In particular, you might find the “time machine” link quite useful.
1) In what ways were the Archean and Hadean eras substantially different from the world we live in today?
And, what do you think, can we apply Hutton’s uniformitarian principles—the so-called “foundation of geology”—to these early portions of earth history?
2) Distinguish between the terms shield and craton , as they are used to describe continental crust.
3) The oldest earth materials (typically certain zircon minerals) exhibit dates of 3.9-4.2 billion years.
But, we consider the planet to be 4.5 billion years old.
Explain why we do NOT find 4.5 billion year old earth rocks?
4) The earliest atmosphere was H and He rich. It then became enriched in CO2. Later O2 dominated.
Explain how and why these changes occurred.
5) Describe the Miller Urey experiment?—make sure that within your answer you specify…
when it was first performed and what was achieved.
6) So where are we now, in terms of understanding life’s origin?
Read your text, and also the following article from another (excellent) University of California Berkeley web site
No one really knows with certainty how life originated. This is a model. It is a good model, based on a lot of evidence (both fossil and lab evidence), but it’s a model!
A) In the very earliest life forms, most scientists believe that the molecule known as _________ utilized and copied genetic information. (fill in blank)
B) And, as you read through the 5 steps…Explain whether or not you think Darwinian “natural selection” potentially played a role (via competition) in the advent of life as we know it. (FYI—I would like a well worded explanation, and not a simple yes/no)
CHAPTER 9: QUESTIONS
1) As one moves southward, from Northern Canada to Mexico , what happens to craton rock ages? Do they get older or younger?
2) What is a banded iron formation (BIF)? Explain what they look like.
BIF’s no longer form in today’s oceans; what was different about Proterozoic conditions that allowed for BIF’s to form?
3) One of the most significant events in the history of life is the appearance of eukaryotic cells. What is so special about these eukaryotic cells?
4) An important Late Proterozoic event is the appearance of multi-celled organisms.
By the very last part of the Proterozoic, the Vendian (also called Ediacaran) Faunas appear.
Describe in your own words what they look like.
Were these related to modern plants and animals?
5) Although your book does not touch upon the subject, some scientists have recently proposed a series of extreme glaciations during the Late Proterozoic. Here’s a good web site:
http://www.snowballearth.org/ (Links to an external site.)Links to an external site. See OVERVIEW section.
AND, the Wikipedia site is pretty good too. https://en.wikipedia.org/wiki/Snowball_Earth (Links to an external site.)Links to an external site.
now… Explain the theory behind what might have caused these so-called “snowball earth” events; and include why it is that the earth did not become forever encased in ice.
CHAPTER 10: QUESTIONS
BEFORE STARTING…view this video,
1) What important event in the history of life marks the boundary between the Precambrian and the Phanerozoic? (This is not specifically a Chapter 10 question.)
2) Your text introduces the Early Paleozoic with a story about Will “Strata” Smith, one of the first field geologists, and in many ways the first person to make geologic maps.
Smith was interested in Paleozoic coal deposits. Not only does England have Paleozoic coal, but so does the U.S.
As a matter of fact, in the U.S. the “Carboniferous” is subdivided into the Pennsylvanian and Mississippian.
What sort of depositional environment would yield coal deposits?
(Make sure you know what geologists mean by the term Depositional Environment)
Does this fit with the location of the U.S. during the Middle Paleozoic (e.g. Silurian) as shown in Figure 10.10?
3) What is an epeiric sea and would you expect them to be more or less common during times of relatively warm global temperatures?
4) What is a transgression?
5) Use your text (and perhaps an on–line search for information regarding the strata of the Grand Canyon).
Is the Tapeats Sandstone a marker of shoreline or deep water conditions?
What features mark this kind of environment?
The textbook used is Historical Geology, Evolution of Earth and Life Through Time, 7th Edition, by Wicander and Monroe.