Earthworm Research
Project
Science in Action!!
1. Niche
What is an organisms niche?
What is the niche of an earthworm?
- they need to move through the soil to eat
dead plant matter so they aerate the soil
and their waste fertilizes it
- they are the basis of many
food chains
2. Habitat
What is an organisms habitat?
What is the habitat of the earthworm?
- they are found all over the world, they prefer
dark moist conditions (no lungs so they breath
through their skin)
- can be 1-20 worms per sq. foot!!
3. Movement
Worms have 2 sets of muscles.
Long ones- run the length of the body. When they
contract the worm is shorter and thicker.
Ring shaped- circle each body segment. When they
contract the worm gets longer and thinner.
Move in a wave like fashiom.
4. Several Factors affect
populations.
Soil temp and moisture, pH, amount of dead plant
matter (food), pesticides and herbicides
Plowed fields have less worms than pastures.
Why?
Impact?
5. Worm anatomy
No eyes- photoreceptor cells, more in front by mouth
than in the back. Why?
Have simple nervous system.
6. Nerve to Muscle
Signal
Worm is a model which can be used to better understand
how human nervous system works.
Nerve cell are connected to a synapse but the synapse is
not connected to the muscle cell.
A chemical messenger (called acetylcholine) must “carry”
the message. And then the muscle contracts.
An enzyme (called acetylcholinesterase)breaks the bond
and deactivates it which causes the muscle to relax.
How could this be linked to Parkinson’s Disease and
others?
7. Aldicarb
Aldicarb is a pesticide that is used worldwide since
1970. Used on cotton, bananas, grapes, hops, lettace,
potatoes…..
Aldicarb upsets the way nerves signal muscles. It has
a similar structure to acetylcholine and causes the
muscles to contract non-stop. Eventually the muscle
is exhausted and stops working.
Its use has been limited in the US. A Professor at UWStevens Point found aldicarb in well water and since
1984 it is very limited in its use.
8. Aldicarb video
9. Make your own
Worm Experiment!
Studying behavior. Behavior is a series of actions in
response to the environment.
Must be observable and measurable.
Use qualitative and quantitative data.
10. How we Do
Science…
Science: “A process for answering questions and solving
problems”
The process of science (scientific method).
What do we already know?
What do we need to know?
What do we do to learn what we need to know?
What do we now know?
What do we now need to know?
11. The Problem…..
Develop a research plan to answer the question: How
do worms react to a stimulant?
Can pick any reasonable and safe stimulant. Your plan
must be written out and approved by me. This report
will be worth 50 points.
Form a hypothesis. Does not have to be “if… then..”
it can be “yes, no” but it must be testable.
Must have a control.
Looking for changes in behavior- not looking to kill
the worm. Want to see: if it is attracted to or avoids,
movement changes, amount of movement, distance
traveled, burrowing time affected etc
Need organized data table/graphs
Must form a conclusion
Will be making a poster and submitting it to UWMilwaukee Professors to be shown possibly at a
conference there in April. The poster will be worth
the other 50 points as well.
12. Example
What do we already know?
Seems to be lots of worms out of the soil when it
rains.
So our hypothesis is = Do earthworms always come out
of the soil when it rains?
What do we need to know?
How much water needs to be present to get worms
out of the soil?
What do we do to learn what we need to know?
- set up an experiment
What do we now know?
- data and form a conclusion
What do we now need to know?
- an experiment in not ever truly over always more
to learn/test
- Does the type of soil matter? Temperature of the
rain? Others???