OVERVIEW:
Students will work in groups of four to conduct experiments related to the
behaviors and adaptations that earthworms have developed for survival in the
environment. Two groups of students will conduct experiments related to earthworm
reactions to light, two groups will examine moisture preferences, and two
will study earthworm responses to odors. At the end of the session students
will share results with other groups and discuss their findings in the context
of animal adaptations to the environment.
TERMS
USED:
Process related—experiment,
control, observation, hypothesis, comparison, classification, prediction,
independent variable, inference, data
Content related—adaptation,
annelid, behavior, burrows, clitellum, consumer, earthworm, environment, food
web, gizzard, hermaphrodite, humus, instinct, invertebrate, learning, mucus,
nocturnal, nutrients, oligochaetologist, reaction; phylum, setae
OUTLINE
OF ACTIVITY:
In the first half of the workshop we will review previous material and then
highlight a researcher at SREL (Karen Gaines) who studies animal behavior.
Given the nature of her work (she studies animal populations and communities)
we will use slides to introduce the students to “the parts of an ecosystem.”
Many of these concepts will be covered in more detail in Activity 5 (e.g.,
food chains, food webs, predators, prey). In the slide program we will also
emphasize that an adaptation is a body part or a behavior that helps an organism
meet its needs. In the experiments the students will conduct on worms (see
below) the primary emphasis is on how the worm’s behaviors (in addition
to its body parts) adapt it to its environment.
For the hands-on activity students will work in pairs, with the pairs at a given table conducting the same experiment to ensure replication. Four pairs of students (2 tables of 4 students each) will conduct an experiment using light, another set of 8 students will conduct an experiment using moisture, and a third group will conduct trials using odor.
For each experiment the pair of students will make a prediction of the worm’s behavior, and then test four worms in the experimental chambers. Each trial should take approximately 15 minutes (2 trials/experiment). While students are waiting for the experiments to finish they will observe and make notes on worm behavior. After each pair/group has completed their designated experiment the pairs, groups, and entire class will share results.
