Interactive Google Slides lesson where students construct and analyze evolutionary trees using real species evidence.

This interactive Google Slides lesson teaches students how to both read and construct evolutionary trees (cladograms) using real biological and molecular evidence. Students move beyond memorizing tree conventions and instead learn how scientists infer evolutionary relationships from data.

Students begin by connecting evolutionary trees to familiar family trees, establishing the idea that both represent patterns of relatedness over time. They learn the core rules and conventions of cladograms and practice interpreting branching relationships and common ancestry.

The lesson then introduces the role of genetic evidence in evolutionary classification. Students examine how DNA comparisons can reveal relationships that are not obvious from appearance alone, including a case study on divergence between closely related species.

Next, students learn how scientists use the principle of parsimony to construct evolutionary trees. Through guided practice, they evaluate multiple possible trees and determine which best explains the data with the fewest evolutionary changes. Students build trees collaboratively and independently using provided organism data sets.

The culminating portion of the lesson is a choice-based investigation. Students select one of ten organism sets and use gel electrophoresis results to construct a DNA-based evolutionary tree. Before analyzing the molecular data, students make predictions based on visible traits, then revise their conclusions using genetic evidence. Each investigation reveals a surprising evolutionary relationship, reinforcing the power of molecular data in modern biology.

This lesson supports students in:

• Reading and interpreting cladograms

• Applying the principle of parsimony

• Using molecular evidence to infer common ancestry

• Comparing trait-based and DNA-based classification

• Explaining evolutionary relationships with evidence

With built-in differentiation through student choice and multiple investigation pathways, this lesson works well as a core evolution application activity or an advanced evidence-based extension. It provides students with authentic experience using data to reconstruct evolutionary history rather than simply being told what the relationships are.

To see a preview of this lesson, click here.

Grade Recommendation

High School: 9th–12th Grade Biology

• DNA evidence, misconceptions correction ("humans evolved from monkeys"), and interpretation of molecular differences make it HS-rigorous.

• Many examples use real datasets (e.g., bears, primates, crustaceans) suitable for Living Environment/Biology.

Cross-Curricular Connections & Extensions

ELA / Critical Thinking

• Students must interpret scientific texts (e.g., Utah Genetics site).

• Explanations require complete sentences and justification.

Math / Data Interpretation

• Reading banding patterns, matching nucleotide differences, and interpreting DNA distance.

Art / Design (Optional Extension)

• Students can design their own evolutionary tree poster.

Optional Extension Ideas

• CER argument: “Why are whales most closely related to hippos?”

• Student-generated cladogram using species in their local environment

• Debate: Is appearance a reliable indicator of evolutionary relationship?
  

Daily slide + literacy - based exit ticket included with purchase

Join the Lesson Laboratory and Teach for Tomorrow!

NGSS Alignment

This lesson is extremely strong for evolution standards because it includes:
✔ comparative anatomy
✔ molecular evidence
✔ interpreting trees
✔ analyzing misconceptions
✔ constructing explanations

High School NGSS Standards

HS-LS4-1

Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence.

• Students use anatomy + DNA evidence to determine relationships.

HS-LS4-2

Construct an explanation based on evidence that the process of evolution results primarily from genetic variation.

• DNA banding and nucleotide differences explicitly highlight variation.

HS-LS4-3

Apply concepts of statistics and probability to support explanations of trait distribution.

• Students analyze DNA band differences and interpret relationship strength.

HS-LS4-4

Construct an explanation based on evidence for how natural selection leads to adaptation of populations.

• Several prompts discuss why misclassification occurs, how traits diverge, and why appearances can deceive.

NGSS Science & Engineering Practices (SEPs)

• SEP 2: Developing & Using Models
  Students analyze, interpret, and mentally reconstruct evolutionary trees.

• SEP 4: Analyzing & Interpreting Data
  Banding patterns, anatomical traits, and DNA sequences.

• SEP 6: Constructing Explanations
  Students explain unexpected relationships multiple times.

• SEP 7: Engaging in Argument from Evidence
  The “Yes/No” justification columns require evidence-based argumentation.

NGSS Crosscutting Concepts (CCCs)

• Patterns
  Students observe trait + DNA patterns to infer relationships.

• Structure & Function
  Anatomical structures do not always reflect evolutionary relationships—one of the lesson’s main takeaways.

• Cause & Effect
  DNA divergence → evolutionary branching.

• Stability & Change
  Myxozoa case: loss of multicellularity shows evolutionary reversal.

• Systems & System Models
  Evolutionary trees are system models showing how parts relate.

Common Core Standards (ELA)

Because students support claims with evidence and write explanations, the following CCSS clearly apply:

CCSS.ELA-LITERACY.RST.9-10.1

Cite specific textual evidence.

CCSS.ELA-LITERACY.RST.RST.9-10.7

Integrate quantitative or technical information from visual models (cladograms, DNA banding).

CCSS.ELA-LITERACY.WHST.WHST.9-10.1

Write arguments focused on discipline-specific content.

CCSS.ELA-LITERACY.WHST.WHST.9-10.9

Draw evidence from scientific texts (and datasets) to support explanations.