Biology 160
Reading Guide 13: Ecosystems, Part I
NAME: _______________________________________
This is DUE: ________________
Come prepared to share your findings with your group.
*As before, please turn in only the Critical Thinking questions on a separate sheet of paper.
Critical Thinking questions: 3, 26, 34, 37, 42, 58, Extra Credit 59
** Fill this reading guide out as you are reading the chapters. This will help you to pull out the important
information that will help us to understand how an ecosystem responds to change.
In this reading guide you’ll learn about:
 The different environments found on Earth
 How scientists can understand how different species form through evolutionary processes
Readings:  Essential Biology, 4th or 5th Ed. (Simon, Reece, & Dickey)
Ch 18, pg. 376-390 (skim!!)
Ch 13, pg. 248-251
Ch 14, all
 Extra Credit! Your Inner Fish, Neil Shubin (2009), Vintage Books, NY, pgs 173-184
While reading these chapters, constantly ask yourself, “How is this information helping me to understand
how life has adapted to so many different environments?”
**We’ve learned a lot about how natural selection in populations works by now, by studying how a population
of viruses and then how a population of humans adapts to an environmental pressure. Now we need to apply
this mechanism to understand how the amazing amount of biological diversity of species on Earth came about.
In order to do this we need to be aware of the amazing variation of environmental pressures that act on life on
Earth and try to understand the time frames through which the slow process of natural selection acts to produce
different species.
Chapter 18, pg 376-390
As you read this, take note of the different environmental pressures that act on organisms.
1. List and describe the various abiotic factors of the biosphere.
This next section addresses organismal ecology: how organisms interact with their environment
2. List and describe the various types of responses organisms have in response to their environment.
3. Critical Thinking: What is the difference between “acclimation” and “evolutionary adaptation”?
This section goes on to describe the diverse environments found on Earth and some of the organisms that
have adapted to life within these environments. Since we’ve run out of time in the quarter, skim this
section to give yourself an overview of the different types of environments found on Earth.
4. What is a “biome”?
5. Describe the different environments and organisms found in the following freshwater biomes:
a) Lakes and Ponds
b) Rivers and Streams
c) Wetlands
6. Describe the different environments and organisms found in the following marine biomes:
a) Oceanic Zones (Fig 18.19)
b) Esturaries
7. Describe briefly how the uneven heating of the Earth creates different climates.
8. Describe the climate of the eight major terrestrial biomes and what organisms (plants and/or animals) you
might expect to find there based only on the pictures provided.
a)
b)
c)
d)
e)
f)
g)
h)
i)
**Once we understand more about how life adapts to different environments and how matter and energy
flow through ecosystems, we’ll come back to look at how human activity is affecting these biomes.
Chapter 13, pg 248-251
9. Think back: on page 247 what is the difference between “descent with modification” and “natural
selection”?
10. What are the fives types of evidence for evolution?
11. What is a fossil and where can they be found?
12. What is the “fossil record” and what does it reveal?
13. What are the oldest known fossils and how far back do they date?
14. What does a paleontologist do?
15. What is biogeography and what does it tell us about evolution?
16. What is comparative anatomy and what does it tell us about evolution?
17. What is homology?
18. What are vestigial structures and what do they tell us about evolution?
19. What is comparative embryology and what does it tell us about evolution?
20. What is molecular biology and what does it tell us about evolution?
21. Make sure you can answer the Checkpoint questions. If not, please write your questions here:
Chapter 14, all
22. What is macroevolution?
23. What is “speciation” and when does it occur?
24. Make sure you can answer the Checkpoint questions. If not, please write your questions here:
25. How does the biological species concept define a “species”?
26. Critical Thinking:
a) So can members of the same species look very different from each other?
YES or NO
b) Can members of different species look very similar to each other?
YES or NO
27. What are some situations that the biological species concept cannot apply and how do biologists respond to
these challenges?
28. Redraw the written information in Figure 14.3 to help you learn the different reproductive barriers that may
exist between closely related species.
29. Describe the two mechanisms of speciation and give an example:
a) allopatric speciation
b) sympatric speciation
30. Compare and contrast the “gradual model” and the “punctuated equilibrium model” of the tempo of
speciation:
31. Make sure you can answer the Checkpoint questions. If not, please write your questions here:
32. What is exaptation and how is this concept used to help explain the evolution of biological novelty?
33. What is the field of “evo-devo”?
34. Critical Thinking: Regarding “evo-devo,” how can “just a few genetic changes […] become magnified into
major structural differences between organisms”?
35. Make sure you can answer the Checkpoint questions. If not, please write your questions here:
36. What are some ways that organisms can fossilize (Fig 14.14)?
37. Critical Thinking: No need to memorize the whole of geologic time scale found in Table 14.1, but please
know how to obtain information from it.
a) Approximately how old is the Earth?
b) When did oxygen begin accumulating in the atmosphere?
c) What are the three Periods when dinosaurs roamed the Earth?
d) What Epoch did the apelike ancestors of humans appear and how many millions of years ago was
this?
e) What Epoch did humans appear and how many millions of years ago was this?
39. What is radiometric dating and how is it used?
40. If a fossil is measured to have a carbon-14 to carbon-12 ratio that is 12.5% of a living organism, how old
would it be?
41. Explain how plate tectonics could have an effect on the evolution of species (macroevolution).
42. Critical Thinking: Go back to the “bottleneck effect” (pg. 260) and suggest why might a species become
extinct?
43. What is a mass extinction? Give an example.
44. How can an explosive diversification happen after a mass extinction?
45. Make sure you can answer the Checkpoint questions. If not, please write your questions here:
46. What is the science of systematics?
47. What is taxonomy?
48. I’m sorry but it must be done: Please memorize the hierarchical classification scheme.
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
(Daring Kids Play Chess On Fallen Guy’s Stomach …or other variations….)
49. Also please note that a species is referred to by its binomial name, that this name is italicized, and that
the genus is capitalized while the species is lowercase. Often the genus is abbreviated with its first initial
such as Homo sapiens = H. sapiens; Escherichia coli = E. coli
50. What are phylogenetic trees?
51. How is homology used to construct phylogenetic trees?
53. What is convergent evolution?
54. How does analogy differ from homology?
55. What is a clade and how are they identified?
56. Redraw Figure 14.25 to help you learn the current three-domain classification system, and be prepared to
revise your drawing in the years to come as more information leads to different hypotheses about the
evolutionary history of life.
57. Make sure you can answer the Checkpoint questions. If not, please write your questions here
58. Critical Thinking: Using the concepts that you learned from the reading, describe how you think two
populations of the same species of organisms could become different species.
Extra Credit!
Your Inner Fish, Neil Shubin (2009), Vintage Books, NY, pgs 173-184
OK, so what’s all the fuss about systematics? The selection from this book, Neil Shubin’s Your Inner Fish,
helps you to understand the wider implications of systematics and taxonomy by using a funny example of
descent with modification to explain how we can find our relationship to other forms of life. Read this to help
prepare you for our quick, but intense, dive into the diversity of life in our next (and last!) reading guide.
59. Extra Credit: Explain how Shubin uses the evidence found in the fossil record to back up his explanation
of the human family tree, from us all the way back to jellyfish (and beyond).