The Fossils pcMEL

The Fossils pcMEL asks students to weigh the connections between evidence and alternative explanations about the relationship between early organisms and information about climate changes of the past. By exploring evidence of variations in the fossil record, students can better understand the issues related to climate change today.

Below are links to resources that will help students use the Fossils pcMEL to make claims and justify the connections between fossil evidence of past climates and current scientific models that present Earth's climate as dynamic and ever-changing.


This article provides an introduction to the Fossils build-a-MEL (baMEL). It is useful even if you are using the Fossils pcMEL with your students. The primary difference between the pcMEL and the baMEL is that with the pcMEL students are given two models and four lines of evidence in a preconstructed diagram where as with the baMEL students choose two models from three and select four lines of evidence from eight to create their own MEL diagram.

Climate Changes of the Past Article Cover
Climate Changes of the Past (Acrobat (PDF) 324kB Feb8 21)

Next Generation Science Standards Performance Expectations

HS-LS4-6: Biological Evolution: Unity and Diversity

  • Create or revise a simulation to test a solution to mitigate adverse impacts of human activity on biodiversity.

HS-ESS2-7: Earth's Systems

  • Construct an argument based on evidence about the simultaneous coevolution of Earth's systems and life on Earth.

The Models

Model A: Many organisms' fossils are missing from the fossil record. We cannot make any conclusions about Earth's past environments from fossils.
Model B: Fossils provide evidence for Earth's changing surface. Understanding past life forms tells us about past environments.

Student Handouts

Lines of Evidence

Evidence #1: Trilobites were small animals that lived at the bottom of the ocean. They fed on organic matter in sediment on the ocean floor. Because trilobite fossils are so abundant and well preserved in the limestone and shale rock of Ohio, they were officially named the state fossil.
Evidence #2: Leaf fossils from Wyoming found in a deep rock layer show a climate that is cooler than that of the fossils found above it.
Evidence #3: The Svalbard forest in Arctic Norway is filled with fossils of tropical trees, called Lycopsid. These trees lived hundreds of millions of years ago.
Evidence #4: Many large geographic areas, like the Blue Ridge and Piedmont regions in Georgia, are made up of metamorphic and igneous rock. Fossils are not usually found in these types of rock.

Student Handouts

Other Resources

This Plausibility Ranking Task (PRT), which may be completed prior to using any MELs, helps students to understand the role of evidence in supporting or refuting models.

Virtual MEL

The Google Drive folder below contains MEL resource documents in the Google formats. In order to maximize the flexibility of our activities, the MEL Project Team wanted to make more resources compatible with virtual settings. We have made our MEL scaffolds available in Google formats, so that they can be copied, modified, and uploaded more easily on a variety of platforms and devices. Please note that to access all the materials for each MEL scaffold, you will need a Google account. View the README file first.

Digital Resources

Prehistoric Climate Change Cover Image
This classroom resource, Prehistoric Climate Change and Why it Matters, from the Smithsonian Institute includes background information and an activity that engages students in leaf margin analysis.