Provide each group of three students a set of the Diversity Sorting Cards (see NSTA Connection). Ask students to spread the cards on the table and examine each one separately. In a discussion with their group members, students consider what type of animal it is and what they know about that particular group of animals, and then predict where the animal might live. Ask students to describe how scientists might classify or group animals and engage students in a discussion about characteristics. After students have had a chance to examine the different animals, ask them to divide the animals into groups based on the following characteristics:

• Animals that live on land and animals that live in the water
• Animals that can fly and those that cannot fly
• Animals with fur or feathers or scales or smooth skin

After students have had the chance to practice classifying animals into different groups based on characteristics, introduce the words mammal, reptile, insect, bird, fish, and amphibian. Share a picture of an animal that falls into each group and ask them to describe the characteristics of the animal and record them on their Animal Classification Sheet (see NSTA Connection). Once they have described the characteristics for each group, ask them to find other pictures of animals that match the same characteristics. Have the students sketch the animal on their sheet in the proper category.

Ask students to return to the large group discussion and help you complete the Animal Characteristics Chart (see NSTA Connection), which can be either enlarged on a poster or projected onto a board. Using the following guiding questions, have students report on their classification activities and record the characteristics that they describe for each group of animals. What characteristics do mammals have? Amphibians? Reptiles? Fish? How are amphibians different from reptiles? How are amphibians and fish similar? What are characteristics of insects? Birds? What characteristics do insects and birds have in common?

Have students select two different animals that are not included in the card sets. The two animals should be from different categories. Ask students to create a Venn Diagram (see NSTA Connection) illustrating the two animals that show characteristics for each and characteristics that overlap for the animals. Using the Venn Diagram, students should be able to report at least one way that the animals are similar. Use the following example to help students get started: Use pictures of a fish and a frog to share two ways that the animals are alike (e.g., they both live in the water at points in their life).

Students provide their initial understanding of living things by brainstorming different types of living things they are familiar with in the engage part of the lesson. They then consider different characteristics and demonstrate their ability to apply those characteristics by sorting cards into different categories and describing the process that they went through. During the explain part students create an overall list of characteristics that help classify diverse animals. Finally, students are asked to compare and contrast two different animals that fall within two different categories.

Students will describe variation between similar species and how the variation assists the animals in their survival.

Begin by showing the students the inside front cover of the book and share with them the map of the route that Darwin took on his voyage between 1831 and 1835. Ask the students what they think Darwin might have been looking for as he visited different countries and continents. Share with them that Darwin was a scientist who explored the world to learn about animals. Begin to read the book to students and discuss the following points:

• p. 2: What interest did the young Charles Darwin have?
• p. 4: What job did Charles take aboard the HMS Beagle? How did the job of naturalist connect to his interest as a child?
• p. 8: What were some of the different animals that Charles saw and wrote about in the rain forest?
• p. 14: What questions did Charles Darwin have as he found the bones of animals that no longer lived on Earth?
• p. 18: What idea did Charles realize about animals and the food they ate?
• p. 24: When Charles climbed the Andes Mountains, what fossilized animal did he find? What conclusion did he come to when he found these fossils?
• p. 30: What type of bird did Charles focus on when he was in the Galapagos Islands? What did he notice about the finches on each different island?

Once students have had a chance to listen to how Darwin gathered information about animals during the voyage, explain that they will be examining pictures of different animals to determine differences or variation between the animals. As students observe the different card sets of pictures (see NSTA Connection), ask them to record their observations about the animals on their Discovering Diversity Student Sheet (see NSTA Connection).

Card Set A— Finches: Remind students that the type of bird that Darwin observed and took field notes about was the finch, which he found had different adaptations. Ask students to examine the different cards in this set and make observations about finch beaks on their sheet.

Card Set B— Galapagos Marine Iguanas: Darwin made notes about iguanas in the Galapagos Islands. Background information on marine iguanas include that they are herbivores and eat mainly seaweed and algae. Larger iguanas may dive to obtain their food as well. Since these animals eat mainly plants that they need to obtain in a marine environment, students should focus on the shape of iguana heads, mouths, and claws as they take notes on their student sheet.

Card Set C— Kallima Butterflies: These butterflies were used to help develop the idea of natural selection by a different scientist in the 1800s. One of the adaptations of this particular insect is that the underside of the wings resembles dead dry leaves when the wings are closed. Ask students to consider why this particular adaptation would help the insect survive predators.

Ask students to return to the full class and discuss the following questions related to the topic of adaptations. As students answer the questions, ask them to support their points with the observations and evidence collected as they explore the card sets.

Why do you think you examined different pictures of the same type of animal to determine if there is a difference in how they look?

Considering the pictures of the finches, describe the differences you observed between them. Why do you think that the shape of the beak is important for where the finch lives and what it eats?

In the pictures of the marine iguanas, you were asked to look at claws, mouth shape, and head shape. Why do you think these body parts would be important for helping iguanas dive for and eat seaweed and algae?

Although a different researcher studied the Kallima butterflies, the information helped Darwin describe natural selection. Why do you think butterflies that had part of their wings look like dead leaves might live longer than brightly colored butterflies?

After students have had the opportunity to explain their understanding of the different adaptations among the three different animals above, ask the students to explain in their own words how adaptations helped animals survive and natural selection occur.

Ask students to complete the peppered moth simulation (see Internet Resources). Read the story of pollution and the peppered moth with students (the second circle option on the screen) and discuss that they are going to investigate how well a bird might see the two different colored moths from a bird’s-eye view. Using a computer or table (Flash must be enabled), ask students to first select the “light forest” and participate in the simulation, which asks them to eat as many moths as possible in a minute time frame. At the end of the minute, students should record their results in the space provided on their sheet using the language shown at the end of the simulation. “Your forest started with 50% light moths and 50% dark moths. Now there are ___% light moths and ___% dark moths. Since you could see ______ moths easier, you ate more ______ moths than dark moths.” Have them repeat the simulation using the “dark forest” and record their results. In the space provided, students complete the statement and use their results as evidence to support their reasoning.

During the explore phase, students can be evaluated on their ability to identify characteristics that are different from each other as they gather information and make observations using the card sorting sets. Their initial understanding is then used in the discussion on adaptations and how adaptations might help in the survival of the animal. Finally, students use evidence from their moth-eating ability in the simulation to support the claim that the moths that have adapted over time and are better camouflaged in their environment have a better chance of survival.