APES Study Guide for Chapter 4: Biodiversity and Evolution
As you read chapter 4, write your responses to the following questions on a separate sheet of paper.
Core Case Study: American Alligator
1. Describe the American alligator’s niche in the subtropical wetland community.
4-1 What Is Biodiversity and Why Is It Important?
2. Define biodiversity. List and describe the four components of earth’s biodiversity.
(Hint: see Figure 4-2).
3. What are three ways in which the American alligator supports one or more of the four components of biodiversity within its environment?
4-2 Where Do Species Come From?
4. What is the estimated number of species on Earth? Define biological evolution .
5. Summarize the process of evolution by natural selection (see pg 83).
6. What are the three adaptations listed that have contributed to the success of the human species and what is the “ good news ” the author includes concerning one of these adaptations?
7. What are the two limits to adaptations in nature through natural selection?
8. Summarize the three common myths about evolution.
4-3 How Do Geological Processes and Climate Change Affect Evolution?
9. State some examples of processes/events and how they have affected evolution through natural selection.
4-4 How Do Speciation, Extinction, and Human Activities Affect Biodiversity?
10. Define speciation , and briefly describe the two types of isolation that can lead to speciation.
11. What are endemic species and why are they especially vulnerable to extinction ? How is global warming thought to have contributed to the extinction of endemic species in Costa Rica?
12. Compare and contrast background extinction and mass extinction.
4-5 What Is Species Diversity and Why Is It Important?
13. How does Figure 4-10 illustrate the two components of species diversity ? Differentiate between species richness and species evenness.
14. What are some measurable differences between communities with high plant species richness and those with fewer species? (See pg 90-91)
4-6 What Roles Do Species Play in Ecosystems?
15. What is an (ecological) niche and how is it different from habitat ?
16. How does Figure 4-11 illustrate the difference between generalist and specialist species? Provide two examples species of each.
17. List three reasons why cockroaches are “nature’s ultimate survivors.”
18. Distinguish between foundation, indicator, keystone, native, and nonnative species.
19. List nine factors that may be contributing to the decline and extinction of so many amphibians.

It is common knowledge in Africa that where you find hippopotamuses, you always find lots of fish. In Africa’s
Lake Edward, located on the border of Uganda and Congo, an ongoing civil war has disrupted the food web that links hippopotamuses and tilapia fish. At night, hippopotamuses wade ashore to feed on the surrounding vegetation. These animals then spend their days in the lake, digesting their food and depositing large quantities of dung into the water.
(An adult hippo produces about 27 kilograms, or 60 pounds, of feces each day!) As the fecal material decomposes, it provides nutrients for algae, which reproduce in large numbers and are consumed by worms and insect larvae. Tilapia fish eat the worms and larvae, and the fish in turn provide food for the local people.
The civil war that began in the Congo in the mid-1990s continues to affect Lake Edward despite a peace accord signed in 2003. Roving bands of armed ex-militia occupy the area near Lake Edward, and they use their automatic weapons to kill the hippos for food and money. Hippo numbers have declined by over 90% and local fishermen are catching far fewer tilapia, a situation that threatens their livelihood. Congolese soldiers and U.N. peacekeepers are slowly disarming and removing the militia groups in hope of stabilizing the hippo population and preventing a serious humanitarian crisis in the area.
> In the space below (or on a separate sheet), use “art” to represent the food web described above.