Life Through Time: Interactive Time Line

Tuesday 1:30pm-2:40pm
Share-a-Thon Part of Share-a-Thon


Molly Miller, Vanderbilt University
Krista Castillo, Metro Nashville Parks


The timeline and the organisms. Both presenters will be there - the paleontologist originator of the idea and the artist who produced the felt-covered rope timeline and the organisms. Options of where this activity is available and/or how it can be put together can be discussed.


We have a color-coded timeline from the formation of the earth to the present at a scale of I inch = 20 million years. Colored zones include: 1) first life;, 2) first complex life; 3) Paleozoic; 4) time during which Middle Tennessee rocks were deposited (Ordovician – Devonian); 5) Mesozoic, with time of dinosaurs striped; 6) Cenozoic, 7) Pleistocene, 8) Holocene.

Specimens of "life" are toy replicas of fossils and extant organisms. The exception is "earliest life" which is represented by a jar of pond scum.

Participants pick an organism and place it next to the place on the timeline corresponding to their guess of the first appearance of that group of organisms. Typically this results in organisms spread all along the timeline.

After retrieving their organism, participants match the color on the underside of the organism to the zone of the same color on the time line. The result is that almost all familiar organisms are clumped near the "now" end of the timeline. The immensity of geologic time and the relatively recent appearance of complex animals are clearly illustrated without referring to unfathomably large numbers of years. The activity holds the interest of both children and adults.


The activity is used to provide temporal context to fossil collecting and long-term environmental change at Fort Negley as well as for its other fossil activities (modelling why there are no dinosaur fossils in Middle TN using a stream table and small bones; examining and touching replica of saber-tooth cat skull found in sinkhole in Nashville... Children are the target audience, but adults are very interested.

Why It Works

The language (e.g., names of eras, periods) and incomprehensibly large numbers used in discussion of geologic time are barriers to developing deep understanding of the most important aspects of the history of the earth and of its life. This activity removes those barriers. Children get the point easily and love playing with the animals. Adults are amazed by the scale and how recently mammals and humans appeared. For the first time they see themselves in the perspective of time.