To introduce students to the amazing variety of life around them.
In this lesson, biodiversity is introduced by having students identify and talk about what they know about the various habitats around them, including the amazing variety of life. Using online resources, they identify the basic components necessary for biodiversity, the critical and countless benefits of habitats, as well as the serious present and future threats to their ongoing existence.
It is not difficult for students to grasp the general notion that species depend on one another and on the environment for survival. But their awareness must be supported by knowledge of the kinds of relationships that exist among organisms, the kinds of physical conditions that organisms must cope with, the kinds of environments created by the interaction of organisms with one another and their physical surroundings, and the complexity of such systems. Students should become acquainted with many different examples of ecosystems, starting with those near at hand. (Benchmarks for Science Literacy, p. 115.)
At this level, students should explore how various organisms satisfy their needs in the environments in which they are typically found. They can examine the survival needs of different organisms and consider how the conditions in particular habitats can limit what kinds of living things can survive. (Benchmarks for Science Literacy, p. 117.) In addition, students should look for ways in which organisms in one habitat differ from those in another and consider how some of those differences are helpful for survival.
The study of biodiversity involves elements of natural history, ecology, and environmental science. To be best understood, biodiversity should be experienced firsthand in the local environment from a range of views, including the scientific, the aesthetic, and the ethical. This lesson, therefore, should follow more direct experiences with biodiversity. Students also will begin to explore the benefits of the wide diversity of living things.
An important goal of this lesson is for students to understand that biodiversity is necessary for life and that species preservation is important to all of us. Every species is linked with a multitude of others in an ecosystem. All animals are part of food webs that include plants and animals of other species. Minor disruptions in a particular ecosystem tend to lead to changes that eventually restore the system. But large disturbances of living populations or their environments may result in irreversible changes. Maintaining diversity increases the likelihood that some varieties will have characteristics suitable to survival under changed conditions. (Science for All Americans, pp. 61, 65.)
Important Note: Classification 1: Classification Scheme and Classification 2: A Touch of Class cover species identification and classification and are prerequisites for this lesson. In the Motivation section, students will be expected to answer review questions based on these lessons.
For some background information on biodiversity, you may want to visit What Is Biodiversity? on the National Wildlife Federation website.
Conduct a basic review of what students have already learned about species classification (based on the two classification lessons that are prerequisites for this lesson). If your class has not already completed the lessons, you may choose to complete them at this time.
Include these questions in your discussion and review of this material:
- What is an organism? What are some examples of animals? Plants? Insects? (An organism is an individual living thing that carries on the activities of life by means of organs which have separate functions but are dependent on each other. Answers may vary for the examples of animals, plants, and insects.)
- How are animals and plants alike? Different? (Some similarities are that they are both organisms that are multicellular [made of more than one cell] and they both have a life cycle. Some differences are that most plants use photosynthesis [use of sunlight] as their mode of nutrition whereas animals use ingestion as their mode of nutrition; plants and animals have different ways of reproduction; and animals have sensory and nervous systems whereas plants do not.)
- What are some ways that we classify different animals, plants, and other organisms? (We can classify living organisms by size, shape, or color.)
- What kinds of features are commonly used to classify them? (They can be classified by where they live, by what they eat, and by their body structure.)
- What kinds of features do mammals have? Offer examples. (They are a group of animals that usually have hair, fur, and nurse their babies with their own milk.)
- What is the benefit of putting organisms into different groups? (Classification is useful because it enables one to make decisions about things [e.g., if one knows that a mammal is part of a group termed primates, then one knows that the animal is intelligent, can grasp things with its hands, etc.]. It is also useful because it allows us to identify similarities and differences among living things.)
- Give an example of an animal or plant that can be put into more than one group based on its features. (A bird is a good example.)
Having looked closer at one aspect of biodiversity—species classification—the class is now better prepared to learn about biodiversity in general. Using the Introducing Biodiversity student esheet, students should visit Biodiversity is the rich variety of life on Earth, where they will gain a basic understanding of biodiversity, why it is important, and the problems that threaten our ecosystems (and the quality of life on earth). Encourage students to take notes as they read.
Note: Throughout this resource, there are many red asterisks next to difficult terms and points of interest. These are interactive Ology Cards. They take a few seconds to load. If time allows and you decide to have students open these cards, tell them to avoid clicking on the “collect me” icon at the top right of the card. Instead, direct them to click on the arrows at the lower right side of each card. They’ll be directed to an area that offers more detail about the term or topic, including interesting comprehension questions.
After reading, include in your discussion questions such as these:
- What does biodiversity mean? (It means variety of life.)
- How are poodles, beagles, and rottweilers alike? How are they different? (They are all dogs. They are different, though, because their genes are different.)
- What is an ecosystem? (Coral reefs, wetlands, and tropical rain forests are all ecosystems.)
- Why is biodiversity important? What are some of the benefits of biodiversity? (Biodiversity is important because it affects the air we breathe, the food we eat, how clean our drinking water is, and is the source of products that come from the earth. Biodiversity helps control disease, provides us with things we need, and can make us happy just by providing us with natural beauty.)
- What is extinction? What is causing it today? (Extinction is when a species disappears, or is extinguished, from earth. Loss of habitat is the largest cause of extinction today.)
- How are we losing our ecosystems today? (We are losing ecosystems today because the earth's populations is growing very fast. Ecosystems get lost as we take over land for homes, factories, and farms.)
- What is the Endangered Species Act? What is it meant to do? (It is a law that is meant to protect endangered species - animals or plants that are in danger of becoming extinct.)
- What are some ways that you could help to protect biodiversity? (Learn everything you can about animals and plants in your neighborhood, and share what you learn with others. Join a project to plant trees, clean local rivers, or tidy highways. Shop at a local farmers market. You also could reduce, reuse, and recycle the items you buy.)
- What would happen if we didn’t have biodiversity? (Answers may vary.)
Among other things, emphasize how human beings also are living organisms who interact with and benefit greatly from the ecosystems around them.
To give students real-life examples of biodiversity and the delicate balance between species within their ecosystems, have them visit Welcome to the Dzangha Sangha and play the Connect the Dots game. Here they will be asked to identify links between different plant, animal, and insect species in a forest, bai (marshy clearing), and river at Dzangha Sangha in the Central African Republic. Have students pause at the end of each ecosystem Q&A so they can see the web of interdependence that connects these species. Encourage them to move their mouse over the yellow dots so they can read more about these living creatures and their interdependence.
When the webs of interdependence appear at the end of each ecosystem activity, ask review questions to check and ensure student understanding. These questions also are found on the Introducing Biodiversity student sheet.
Questions about the forest web:
- In what ways do the BaAka people use trees? How does the African pied hornbill use them? (The BaAka people rely on the forest for food, medicine, and building materials. The pied hornbill uses them to nest and for fruit to eat.)
- What are the different birds shown in this ecosystem? How are they alike? Different? (There are the pied hornbill and the African harrier hawk. They are alike in that they both eat fruit and they are birds. They are different in that one has a large beak and also likes to eat insects along with the fruit.)
- How do leopards both give and take away life in this ecosystem? (Leaopards provide food for butterflies that eat the large cat's dung. The take away life because they are meat eaters and feed on animals in the forest.)
- If the leopards become extinct, how might this affect the other species that are connected to it? (Answers may vary.)
Questions about the Bai web:
- How are the BaAka people dependent on the dwarf antelope and other small mammals like it? (They rely on those animals for food.)
- How is the water pool used in this part of the ecosystem? (It is used for its mineral-rich water, which butterflies drink, and for its mud, in which the elephants wallow.)
- Which species in this ecosystem rely on plants? Explain. (All of the species in this ecosystem rely on plants for shelter, food, medicine, or materials.)
- Imagine that the speckle-lipped mabuya became over populated in the bai. How might this affect the ecosystem? Explain. (Answers will vary.)
Questions about the river web:
- What is one way the BaAka use trees from this river ecosystem? (The BeAka use trees from this river ecosystem to make canoes.)
- How do crocodiles and Egyptian plovers relate to each other? (The Egyptian plovers pluck food from between the crocodiles' teeth.)
- What kinds of foods does the golden barb eat? Do you think it could survive if spiders in the river area became extinct? Why or why not? (The golden barb eats algae, insects, seeds, and spiders. Yes it could because it has other sources of food.)
In addition to regular comprehension questions, have students think about benchmark-based questions such as:
- In what ways do insects and animals use plants in these ecosystems?
- In what ways do plants benefit from animals?
- In what ways do humans use plants? Animals? Ecosystems?
- What happens when an animal dies in its own ecosystem? How can this benefit the ecosystem?
- What might happen if humans decided to cut down trees in one of the ecosystems to build new apartment buildings?
- What might happen if humans decided to protect these ecosystems?
Answers may vary. Encourage students to explain their answers.
Some of these questions can be answered by having students visit Bio-Benefits, which emphasizes the many benefits that biodiversity provides for human beings and other living species alike. Have students address these questions in your ongoing discussion:
- How do plants give us clean air to breathe? (They take carbon dioxide out of the air and put oxygen into it.)
- How do forests help to keep our drinking water clean? (Forests and wetlands around the world filter our usable water again and again, constantly recycling the water we use for drinking.)
- What are some examples of how ecosystems affect cultural traditions? (Ecosystems can affect what type of instruments people play, the kinds of decorations they use, and mythology.)
- Which animal species inspired the invention of the airplane? (Birds.)
- What kinds of things do people do for fun in ecosystems? (People hike and canoe in the great outdoors. They also enjoy the natural beauty provided by an ecosystem.)
- How do ecosystems help us to live longer, better lives? (Ecosystems provide food, medicine, clothes, and more.)
As a way to better see and apply what they have learned, inform students that they will be expected to find a local ecosystem to explore, collect data on the different species that live there, and present their findings to the class. Their chosen ecosystem can be a backyard, a city park, a neighborhood area, or any other natural place. Pass out and review with the class the Explore the Outdoors student sheet, which they will use to record information on the various species they encounter in these areas. Once students have completed their objective and assignment sheet, pass out poster paper and crayons/markers so they can draw a picture of the ecosystem and the eight species they documented. On their posters, they should attempt to draw a web of interdependence between these different species, similar to the Dzangha Sangha online activity, including descriptions. When finished, have each student present their ecosystem to the class for further analysis and discussion.
For review and reinforcement purposes, have students visit What Do You Know? and take the 10-question online quiz on biodiversity.
Note: Students will not be able to check their answers when finished, because this website prompts users to sign in in order to reach the answer section. As a result, direct students to not click on “Check Your Answers.” Instead, you may wish to read over and discuss their answers together as a class.
For related Science NetLinks lessons see:
There are additional resources at the American Museum of Natural History’s Ology website which can broaden students’ understanding of both the benefits and the challenges of biodiversity:
- Students can visit the Global Grocery and explore some of the common household products that result from biodiversity.
- At Going Going…Gone?, students can find out what is causing the extinction of species.
- At Saving Species, students can learn more about ongoing research dedicated to saving endangered species in the Bahamas, Madagascar, and Australia.
- Students can play the Endangered Species Game, which teaches them about the Endangered Species Act.