Lessons in Evolutionary Biology

Preschool - Kindergarten: Variation


Learning Experience

We will make observations about how living things are different from one another. This is important to understanding biological evolution because variation (differences) among living things makes it possible for some organisms to survive better than some other organisms. We can use observations to make claims about the differences we see in living things.


We will begin to understand that living things differ in many ways, and that these differences can be called variation.

Materials and Preparation

a pencil and paper on a notebook or clipboard for each student; large baggie for each student for collecting leaves.


Focusing Questions: How are living things in the world different from one another? Are all animals alike? Are all trees alike? Are all the leaves on one tree alike?

Focus: We can see that the world around us is full of variety (also called diversity). Can we think of some ways the living things of the world are different from each other (e.g., some animals live in the ocean and some on land; some fly and others crawl; some plants are tough and woody and some are soft and easily crushed; etc.)?

Explore: Take a walk. Collect as many leaves as you can find, from as many different plants as you can (you can also gather a few leaves from the same plant). Spread out your finds and compare the leaves. How are they all alike? How are they different? Are all the dandelion leaves alike? How about all the leaves that came from the same plant?

Reflect: Let’s draw some pictures showing the variations we can see among the leaves we collected. Can we think of reasons why these leaves might be so different?


Use pictures or toy animals or even other living things (like insects, for example), and ask your students to discuss examples of variation in other types of organisms. Can they think of ways in which the organisms vary? Can they suggest reasons for the differences among living organisms?

Science Grade Level Expectations Addressed (WA State EALRs):

Students know that: Students are expected to:
2-3 LS3A There are variations among the same kinds of plants and animals. Give examples of variations among individuals of the same kinds of plants and animals within a population (e.g., tall and short pine trees, black cats and white cats, people with blue eyes or brown eyes, with freckles or without).