2 1. Niche What is an organisms niche? What is the niche of an earthworm?- they need to move through the soil to eatdead plant matter so they aerate the soiland their waste fertilizes it- they are the basis of manyfood chains
3 2. Habitat What is an organisms habitat? What is the habitat of the earthworm?- they are found all over the world, they preferdark moist conditions (no lungs so they breaththrough their skin)- can be 1-20 worms per sq. foot!!
4 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.
5 4. Several Factors affect populations. Soil temp and moisture, pH, amount of dead plant matter (food), pesticides and herbicidesPlowed fields have less worms than pastures.Why?Impact?
6 5. Worm anatomyNo eyes- photoreceptor cells, more in front by mouth than in the back. Why?Have simple nervous system.
7 6. Nerve to Muscle SignalWorm 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?
8 7. AldicarbAldicarb is a pesticide that is used worldwide since 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 UW- Stevens Point found aldicarb in well water and since it is very limited in its use.
10 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.
11 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?
12 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.
13 Looking for changes in behavior- not looking to kill the worm 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 etcNeed organized data table/graphsMust form a conclusionWill be making a poster and submitting it to UW- Milwaukee Professors to be shown possibly at a conference there in April. The poster will be worth the other 50 points as well.
14 12. Example What do we already know? Seems to be lots of worms out of the soil when itrains.So our hypothesis is = Do earthworms always come outof the soil when it rains?What do we need to know?How much water needs to be present to get wormsout of the soil?
15 What do we do to learn what we need to know? - set up an experimentWhat do we now know?- data and form a conclusionWhat do we now need to know?- an experiment in not ever truly over always moreto learn/test- Does the type of soil matter? Temperature of therain? Others???