Evidence for evolution and common ancestry takes centre stage in this Grade 12 Science worksheet, where students investigate how fossils, anatomical structures, geographic distributions, and molecular sequences help scientists reconstruct evolutionary history. Using examples such as fossils from Dinosaur Provincial Park in Alberta, learners examine how independent lines of evidence strengthen explanations of evolutionary relationships.

Rather than relying on a single observation, students explore how evidence from different scientific fields can support the same conclusion. They distinguish homologous structures from functional similarities, interpret DNA sequence comparisons, and consider why agreement among fossil records, comparative morphology, biogeography, and molecular phylogenetics provides stronger evidence for common ancestry.

From ancient fossils to molecular relationships

The informational passage introduces the fossil record as evidence of changes in organisms and biodiversity through geological time. Transitional fossils provide combinations of features that help researchers investigate evolutionary relationships, while comparative morphology reveals shared anatomical patterns that may reflect common ancestry even when structures perform different functions.

Students also examine biogeography, which connects species distributions with geological history and isolation, and molecular phylogenetics, which uses DNA or protein sequences to infer relationships among organisms. The worksheet links these concepts to natural selection and speciation, including how geographic isolation and inherited differences can contribute to population divergence over generations.

How students apply the evidence

• Reading comprehension: Identify key ideas about fossils, homologous structures, geographic distributions, and molecular evidence.
• Multiple-choice questions: Apply evolutionary concepts to anatomical comparisons, transitional fossils, DNA sequence differences, and relationships among species.
• True-or-false statements: Evaluate claims about geological evidence, structural homology, molecular phylogenetics, and natural selection.
• Short-answer responses: Explain evolutionary change across geological periods, interpret similarities in DNA sequences, and justify combining independent evidence sources.
• Labeled diagram and categorization activities: Extend the lesson through visual interpretation and classification.
• Short-note activity: Consolidate key ideas about evolutionary evidence and common ancestry.

Included resources for students and teachers

• ✔️ Printable student worksheet focused on evidence for evolution and common ancestry.
• ✔️ Separate PDF answer key for checking student responses.
• ✔️ Student Notes lines at the bottom of the worksheet for recording important concepts.
• ✔️ Teacher Guide within the Answer Key PDF, featuring Learning Objectives, Teaching Tips, Discussion Questions, and Common Mistakes.

Bring evolutionary reasoning into Biology 30

Use this Grade 12 evolution worksheet after introducing evolutionary evidence, during a unit review, for independent classroom practice, or as homework. Students move from interpreting information in the passage to evaluating claims and explaining why multiple forms of evidence matter when investigating common ancestry.

The resource is particularly useful for reinforcing scientific reasoning: students must distinguish what an individual fossil can reveal from what a wider fossil record suggests, recognize that homologous structures can have different functions, and interpret molecular similarities as evidence that must be considered alongside other findings.

For teachers working with the Alberta Biology 30 topic, this resource combines core evolutionary concepts with a recognizable Alberta fossil locality and a separate answer key and teaching guide. It provides a focused way to review evolutionary history while giving students practice explaining how scientists build evidence-based conclusions about relationships among living and extinct organisms.