Biology · 10th Grade

Active learning ideas

Evidence from Molecules and Geography

Take your students on a journey from the Galapagos Islands to the genetics lab. This topic uncovers the modern evidence that forms the bedrock of evolutionary theory.

• Common Core State Standards
• NGSS: HS-LS4 Biological Evolution: Unity and Diversity

• 30–50 min
• Pairs → Whole Class
• 3 activities

Activity 01

• Collaborative Problem-Solving
• 45 min · Pairs

Pipe Cleaner Phylogeny

Students use different colored pipe cleaners to represent DNA sequences of several related species. They physically compare the 'sequences' to find differences and then group them together to build a simple, tangible phylogenetic tree, demonstrating how molecular similarities reveal evolutionary relationships.

Explain how the distribution of species, also known as biogeography, supports the theory of evolution.

Facilitation Tip

Start with very short, simple sequences and gradually add more species to scaffold the complexity of the task.

What to look for

Provide students with a short DNA sequence from a 'mystery' organism and sequences from three known organisms. Ask them to determine which known organism is the closest relative and justify their answer in one sentence.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 02

• Collaborative Problem-Solving
• 50 min · Small Groups

Island Biogeography Mapping

Using a map of a fictional archipelago, students model how a single ancestral species from the mainland could colonize the islands and diverge into multiple new species over time. They draw arrows and label islands with new traits based on different environmental pressures, illustrating adaptive radiation.

Analyze DNA or amino acid sequence data to infer evolutionary relationships between organisms.

Facilitation Tip

Provide 'event cards' that introduce new environmental challenges like volcanic eruptions or new food sources to guide the simulation.

What to look for

Students analyze a case study packet containing a map, fossil data, and amino acid sequences for a group of related species. They must then write a comprehensive explanation, citing all three types of evidence, to describe the evolutionary history of the group.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 03

• Collaborative Problem-Solving
• 30 min · Individual

Cytochrome C Analysis

Students are given a table with the number of amino acid differences in the Cytochrome C protein between humans and several other animals. They use this data to infer which organisms are most and least closely related to humans and then sketch a cladogram to represent these relationships.

Justify the claim that molecular data provides some of the strongest evidence for common ancestry.

Facilitation Tip

Remind students that a smaller number of differences implies a more recent common ancestor.

What to look for

Students complete a KWL (Know, Want to Know, Learned) chart at the beginning and end of the unit, reflecting on their understanding of how molecular and geographic data are used as evidence for evolution.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

A few notes on teaching this unit

Begin with the concrete concept of biogeography, using compelling examples like Australian marsupials or island finches. Then, introduce molecular data as a powerful, microscopic tool that confirms and refines the patterns we see on a global scale. Use analogies, such as comparing family trees to phylogenetic trees, to make the concepts relatable and accessible.

Upon completion, students will be able to analyze molecular and geographic data to construct compelling, evidence-based arguments for common ancestry and evolution.

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Watch Out for These Misconceptions

• Humans evolved from the monkeys we see today.

  Humans and modern monkeys share a common ancestor that lived millions of years ago. This ancestor was neither a modern monkey nor a human, but an earlier primate from which both lineages diverged.

• More genetic differences always means the organisms look more different.

  The location of a genetic mutation matters greatly. A small change in a critical developmental gene can cause a huge physical difference, while many changes in 'junk' DNA might cause no visible difference at all.

• Biogeography is just about where animals live now.

  Biogeography is the study of species distribution over both space and geological time. It considers how past events, like continental drift, shaped the current locations of species and their ancestors.

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Methods used in this brief

• Collaborative Problem-Solving