Fossil Dating, a Link to Earth's Past
Lesson 4 of 8
Objective: Research when different species appeared on Earth, then create a timeline that includes accurate placement of at least 3 different species on that timeline.
My class has been discovering how fossil records show the time order that organisms lived on Earth based on where the fossil is found. For this lesson, I wanted my students, while working collaboratively, to predict the placement of certain organisms on a timeline of when organisms first appeared on Earth.
Students worked in collaborative groups of four. They received a total of four species cards. I had written the name of the species on post-its in order to make the activity more manageable. Then, before researching, each group had to place them on the timeline, we used a sentence strip for the timeline when working in groups. Once they had placed them where they thought they should be, we displayed them in class and used a carousel strategy to predict which group would be the most accurate before we went to work to see if our predictions were close.
Not all groups had the same combination of species for this reason, students used the internet to research when all of the animals, on the list, appeared on Earth. This activity really helped them sharpen their skills when using a search engine. They soon learned that adding too many words would give you too many possible sites that may have the answer. The students placed their predictions on the timeline as seen here, Sample Prediction Timeline. Then students worked collaboratively to piece the information together and finally reworked their timeline to match the correct dates using Animals on Earth Timeline I created.
Class Discussion/Wrap Up
Once we had all of the information, students did a gallery walk to see how the groups fared when completing their timeline without the research. There was a lot of discussion about how dinosaurs came after fish and amphibians they were really surprised to learn that fact. We then made a large timeline. I used a meter stick as the measure of 1 million years and then together we plotted the organisms. The students realized three things during this lesson, first that you cannot have accurate data without research, next, that millions of years went by before new species appeared on Earth, and lastly, that fossil records help date when an organism once lived. This is the Organisms on Earth Timeline list that I used. I gave them four post-its with four different organisms.