Honors Biology Reading Guide
Name
Chapter 15: Tracing Evolutionary History
Period
Chapter 15: Tracing Evolutionary History
Section 15.1 Conditions on early Earth made the origin of life possible
1. How long ago is it approximated that Earth was formed?
2. As Earth was forming the atmosphere was much different than what we see today. Describe the first
atmosphere of the Earth as it was forming.
3. Describe what the earliest evidence of life on Earth was and how old they are.
4. Why are stromatolites considered to NOT be the first life forms on Earth?
5. How long ago is it thought that life started on Earth?
6. From the time of the early Greeks it was thought that life arose spontaneously, that life arose from nonliving
matter. Explain how this thought was disproven, in what year, and by whom.
7. Since the time of Luis Pasteur scientists have hypothesized, based on observations and experiments, the
origins of life. They have hypothesized that the conditions on early Earth could have produced very simple
cells through a sequence of four main stages. Describe the 4 main stages that scientists believe gave rise to
life on Earth.
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15.2 Stanley Miller’s experiments showed that the abiotic synthesis of organic molecules was possible
8. In 1953 Stanley Miller became famous for what?
9. Why is it thought that the present-day conditions on Earth do not allow for the spontaneous synthesis of
organic compounds?
10. Provide a brief description of Stanley Miller’s experiment that supported the idea that organic material can
be formed from inorganic material.
11. Which of the 4 stages in the hypothetical scenario of the origin of simple cells was Stanley Miller testing in
his experiment?
15.3 The formation of polymers, membranes, and self-replicating molecules represents stages in the origin of
the first cells
12. How are polymers synthesized?
13. In the cell, enzymes catalyze the reaction of polymers. Stanley Miller showed that small organic molecules
could be formed from inorganic material during what is believed to be the conditions of early Earth.
Explain how scientists have shown that it is possible to form more complex organic molecules, i.e.
macromolecules, without the use of enzymes.
14. Which of the 4 stages in the hypothetical scenario of the origin of simple cells is being tested in this
experiment.
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15. Explain what a protobiont is.
16. Explain what evidence is used to suggest that it is possible for protobionts to spontaneously form from
abiotically produced organic compounds.
17. Explain how these small membrane bound droplets of lipids display some of the properties of living cells.
18. Which of the 4 stages in the hypothetical scenario of the origin of simple cells is being supported by the
above information?
19. What is one hypothesis for the first genes within living organisms?
20. Explain the sequence of events that would have led to the formation of RNA as genetic material.
21. Which of the 4 stages in the hypothetical scenario of the origin of simple cells is being supported by the
above information?
15.4 The origins of a single-celled and multicelled organisms and the colonization of land are key events in
life’s history
22. Now that we have a plausible/hypothetical origin of life on earth and thus the creation of the first single
celled organism we can now take a brief look at how life as we know it formed. Prokaryotes are at the
center of this transformation of life as we know it by producing the type of oxygen rich environment that is
needed. Approximately when did prokaryotes begin transforming the Earth’s atmosphere?
23. How did the first prokaryotes transform Earth’s atmosphere, a revolution of sorts?
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24. When did single-celled eukaryotes appear on Earth?
25. When did multicellular eukaryotes appear on Earth?
26. What is the Cambrian explosion and when did it occur?
27. When did large forms of life such as fungi, plants, and animals begin to colonize land?
15.14 Phylogenies are based on homologies in fossils and living organisms
26. What is phylogeny?
27. What kind of evidence is used to construct the phylogeny of a species?
28. Explain convergent evolution.
15.15 Systematics connects classification with evolutionary history
29. What is systematics?
30. The system of naming and classifying species was introduced in the 18th century by Carl Linnaeus.
Although his system is not based on evolutionary relationships it has provided many useful features. What
are 2 useful features of the Linnaeus’s system?
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31. Why is using the common names for organisms often time too ambiguous, or confusing/unclear?
32. What are the 2 parts to an organism’s scientific name?
33. How do we go about writing the scientific name?
34. List the hierarchical categories of Linnaeus’s classification system in order from most specific/least broad
to least specific/most broad.
35. Although Linnaeus’s system is very useful in organizing living organisms, as mentioned previously, it is
not based on evolutionary relationships. Today, taxonomists are working on a classification that reflects
evolutionary relationships. What is it the taxonomists traditionally use to classify organisms based on their
hypothesized evolutionary relationships?
Review 13.6 in your text and Chapter 13 Reading Guide for understanding phylogenetic trees
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