Students in Mrs. Emily Cloud’s Advanced Placement Biology class created a geologic timeline spanning 4.65 billion-years of Earth history, compressing it into a scale of 100 meters. Students used pre-measured string to represent the existence span for various groups of plants and animals.
The goal was to show the depth of earth history and how and when various fossil life originated, evolved and/or went extinct. Each student was assigned a living thing and students then researched the range of years that their species existed. Students then determined how long their assigned species existed in relationship to the 4.65 billion years that the Earth has existed, figuring out how long to make the string representing the existence span of their creature.
Starting at the Precambrian end and working forward in time, each life form’s timeline was placed down. Students placed one end of the string on the ground where their organism began and the other end where the organism went extinct, or to the present day if it still survives. Students then discussed if organisms have to be big, powerful, or intelligent to be successful, and if they could use a time machine, what part of the timeline would they most want to visit and why. The class also discussed the number of mass extinctions survived, total time spent on earth versus body size and complexity and behavioral sophistication.