Students will study two animals to understand how their variations give each a survival advantage.
Members of a species are alike in many ways. However, individuals within a species show small differences. Variations are differences in appearance of an inherited trait among the members of a species. Variations can be observed in traits related to size, shape, behavior, function, and body parts. Most variations are minor and include differences in hair color, texture and length of fur, and flower color. Others may be major and quite apparent, like a cat with six toes on each paw or an albino deer. All of these variations are inherited and can be passed down to the offspring from the parent organism.
Variations in species may affect their ability to survive in a changing environment. During the course of many generations, a variation that provides a survival advantage can become widespread in a population because individuals with it have a higher probability of reproducing and surviving. If a species is unable to adapt to its changing environment, it can become extinct. Dinosaurs are an example of this.
Plant breeders take advantage of variations to produce improved crops. For example, United States potato farmers spend millions each year on pesticides, but insects become resistant to these pesticides. In Bolivia, a species of wild potato has hairs on its leaves that release a sticky chemical when touched. The hairs act like flypaper and trap pests that feed on the leaves of the potato plant. However, these potatoes are very small. Through plant breeding, scientists have been able to combine the trait of large size of the U.S. potatoes with the insect-resistance trait of the Bolivian potatoes to develop a high-yielding, large, insect-resistant variety of potatoes.
1. Use Science Process and Thinking Skills
Invitation to Learn
Show students a picture of a klipspringer antelope and a picture of a mountain goat. Ask them to think about the physical characteristics of each as you explain them to them. The information about these two antelopes is located on the Mountain Goat and Klipspringer Animal Cards overhead transparency. While both antelope live in the mountains on small ledges, the klipspringer has an amazing variation that allows it to leap from rock to rock without falling. Its rubbery hoofs allow it to grip the rocks as it jumps from one to another on the rocky slopes of the African mountains. The students will participate in an activity that will test their jumping ability.
Divide the students into pairs. Give each pair of students four square sheets of paper measuring 8" x 8", 6" x 6", 4" x 4", and 2" x 2". Lay the sheets of paper on the ground approximately one to one and one half feet apart from one another. One student at a time will try to jump from paper to paper without falling off any of them. This will help them make the connection that the klipspringer's hoof variation truly does help it survive in its environment and how important species variations are to the species' survival.
Students will work in pairs to study related organisms that live in different environments. To teach the students how to do this activity, you will model it using the klipspringer and mountain goat.
Line 1: Noun (one of the animals)
Line 2: Two adjectives describing first animal
Line 3: Phrase beginning with an "ing" word (participle) that describes what the noun does and where
Line 4: Three participles describing both animals
Line 5: Phrase beginning with an "ing" word (participle) that describes what the noun (other animal) does and where
Line 6: Two adjectives describing the other animal
Line 7: Noun (the other animal)
Landing on narrow, rocky mountain ledges in Africa
Jumping, gripping, traveling
Rock climbing to dizzying mountain heights in Alaska
Instead of writing diamante poems, student pairs could write Poems for Two Voices and share them with the class. To write these poems, students are grouped in pairs. You can stipulate how many stanzas you want the poems to have. A stanza consists of three lines that do not need to rhyme. You could list the points from the lesson that you would like covered in the poems and they could include the information covered on their Animal Variations Charts. An example of a poem about klipspringers and mountain goats follows:
Animal Variations Poem for Two Voices Klipspringer and Mountain Goat
I am a klipspringer
I am a mountain goat
We are both antelopes
I live in Africa
I live in North America
We both live on mountain cliffs and ledges
I jump from rock to rock on small mountain ledges
I climb on rocks on the steep mountain slopes
We both have spongy, springy hoofs
I have a long brownish-gray bristly coat
I have a long, hairy white coat
Both of our coats protect us in our environments
I eat fruits, flowers, moss, and succulents
I eat grass, sedges, and lichens
We both have to search in treacherous circumstances for our food
I stay with one mate throughout my life
I live in herds of up to ten mountain goats
We both have one or two offspring a year
Students may choose to present the poems in a variety of ways including:
If you choose to have your students follow choice number one, the pairs of students can write their poems on overhead transparencies using three different colors of markers; a separate color for each student and another for the line they read together. The students then present their poem to the class by displaying on the overhead projector and reading it together. You may want to have the students illustrate their poems with accurate drawings of the animals they researched.
Lambert, M. & Carpenter, M., (2005). Visual learning: Using images to focus attention, evoke emotions, and enrich learning. MultiMedia & Internet@Schools, 12.5, pp. 20-24.Using graphic organizers can help students on all levels understand content concepts more clearly as they help the students organize the material. This can be especially true for students reading below grade level as the organizers can help them with reading comprehension. It is also helpful with gifted learners as it helps them bridle and categorize their expansive thinking.
McCoy, J. D., & Ketterlin-Geller, R., (2004). Rethinking instructional delivery for diverse student populations: Serving all learners with concept-based instruction. Intervention in School & Clinic, 40.2, pp. 88-95.