These Human Body experiment lessons should be used with lessons about the scientific method (especially if your school does a science fair). Each experiment in the series will identify the following topics:

• Question

• Hypothesis

• Materials

• Experiment

  o Procedure

  o Control, independent, and dependent variable

• Results

• Conclusion

When explaining an experiment to the students, refer to the Scientific Method. This will help the students understand these concepts in an applied setting. Hopefully, this will also help in their experiment idea generation or help them correctly identify their controls and variables within an already established experiment. Another option for the human body experiment series is to teach these lessons as the students learn about the human body, specifically as a follow-up to the Great River Lesson.

The atlatl was a spear-throwing tool that we think was invented during the Paleolithic era, but it could be, in fact, much older. With a notch for the spear to rest on, the shaft functionally extends the forearm, creating more leverage for the thrower. In addition, the atlatl increases the throwing lever of the arm, and this extra length increases the amount of force transferred to the spear over a longer distance. The result is a system of levers that imparts more energy into the spear, increasing the speed, distance, and penetration ability. The name “atlatl” comes from the Aztec language Nahuatl, and the Aztecs could launch spears hard enough to pierce the armor of the Spaniards.

While the earliest remains of an atlatl can be traced back to around 18,000 years ago, there is evidence that the tool was invented way before that. There is fossil evidence of a Homo sapiens from 42,000 years ago with arthritis in his elbow. This suggests a wear and tear injury from repeated throwing motions consistent with atlatl spear throwing. The atlatl was invented to help take out megafauna during the last Ice Age. You would need a mighty throw that could penetrate the tough hide of large animals. It would still need to be effective from longer distances to provide some safety against such large animals.

Variations of the atlatl would continue to be used in Europe, with improvements like adding a strap, which increased range and rifled the spear. Native Americans, who brought the technology over the Bering Land Bridge, would continue using the atlatl, bow, and arrow. The atlatl was featured in the iconography of many Central and South American cultures, including the Mayans, who had a spear-throwing owl god who used the tool. The atlatl may have been one of the most important early human inventions. It ensured their survival through more efficient hunting techniques.

Minimum Amount: This experiment can be done with just one person. They would throw a spear, measure the distance, and throw again with the atlatl. However, they won’t have much data to compare against. On the other hand, with many students, there will be plenty of data to see if the atlatl allows someone to throw farther.

Materials: 

·      A vast playing area

o   This lesson is best done outside in a big park or outdoor area

·      Several junior atlatl sets

o   While these can be handmade, I purchased several sets

·      Pencil and paper

·      A tape measure

·      A measuring wheel

·      A large whiteboard or writing pad to record the data

Age: Upper elementary and middle school