Spanish versions of these resources are also available for download (en Español).
In the film, Popped Secret: The Mysterious Origin of Corn, George Beadle was the first to propose that teosinte is the wild ancestor of maize. At first, few scientists agreed with this hypothesis because there did not seem to be enough supporting evidence. Later in his career, Dr. Beadle undertook a huge genetic experiment to get the evidence needed to make a stronger case for his hypothesis.
In this lesson, students will use Punnett squares to model crosses if one, two, or three genes are involved in determining the differences between teosinte and maize. Then, they develop a mathematical model to make further predictions, and use those to explain the main conclusion of Dr. Beadle’s research and how it supports his hypothesis about maize’s origins.