Evolutionary Relationships

Overview

This is Lesson 14 of 18 in the "Exploring Speciation in Biodiversity" unit for Year 13 Science students at Wellington College. The focus is on interpreting and constructing phylogenetic trees to trace evolutionary relationships among species and understanding their importance in defining species.

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Curriculum Alignment

New Zealand Curriculum Links

Learning area: Science
Strand: Nature of Science / Living World
Level: Year 13

• Nature of Science: Understanding evolutionary biology concepts through constructing and analysing phylogenetic trees as representations of evolutionary relationships.
• Living World: Concepts of speciation, biodiversity, and evolutionary relationships.

Achievement Objective(s):

• Explain how evolutionary relationships between organisms are represented visually and interpreted through phylogenetic trees.
• Construct and analyse phylogenetic trees to infer patterns of descent and speciation.
• Discuss the role of evolutionary relationships in defining species boundaries.

Key Competencies:

• Thinking: Interpreting complex visual data; understanding relationships and evidence.
• Using language, symbols, and texts: Reading and constructing phylogenetic trees—a specialized scientific text.
• Relating to others: Collaborative discussions during group work.
• Participating and contributing: Sharing findings and explaining interpretations.

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Learning Intentions

WALT (We Are Learning To):
Interpret and construct phylogenetic trees to reveal evolutionary relationships.

Success Criteria:
By the end of this lesson, students will be able to:

• Construct a phylogenetic tree from given data using scaffolded worksheets.
• Analyse and interpret phylogenetic trees to identify relatedness and ancestral lineage.
• Discuss the importance of evolutionary relationships in defining species boundaries.

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Resources Needed

• Scaffolded worksheets for constructing phylogenetic trees (tiered for differentiation).
• Example datasets on traits or genetic sequences of various species.
• Whiteboard and markers.
• Projector or interactive screen for teacher-led explanations.
• Online phylogenetic tree building tools (optional for extension or assessment at home).
• Copies of Māori perspectives on biodiversity and genealogies (whakapapa) for cultural integration.

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Lesson Timeline (55 minutes)

Time	Activity	Description
0-5 min	Introduction	Briefly revisit previous lessons on speciation and biodiversity. Introduce today's focus: phylogenetic trees as tools for investigating evolutionary relationships. Show a simple example tree.
5-15 min	Teacher Explanation	Explain what phylogenetic trees represent—common ancestors, divergence, evolutionary relatedness. Discuss branches, nodes, clades, and traits used to build trees (morphological/genetic). Link to species concepts. Include Te Ao Māori concepts of whakapapa as genealogies that connect species and people.
15-35 min	Scaffolded Group Activity	Students work in pairs/small groups using scaffolded worksheets to construct phylogenetic trees from a provided dataset. Worksheets include prompts and differentiated support (e.g., guided clues for less confident students). Teachers circulate, support, and question guiding deeper understanding.
35-45 min	Tree Analysis and Interpretation	Groups compare their trees. Discuss similarities and differences. Students interpret relationships shown, such as which species share recent common ancestors and what that implies about speciation.
45-50 min	Whole-Class Discussion	Discuss importance of evolutionary relationships in defining species boundaries. Highlight how phylogenies reflect biodiversity and support conservation decisions. Invite students to share Māori worldview connections to whakapapa and biodiversity.
50-55 min	Success Criteria Reflection & Extension	Students self-assess against success criteria. Extension challenge: Explore an online phylogenetic tree builder with more complex datasets for advanced learners or suggest research task on unusual evolutionary relationships or speciation examples.

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Differentiation Strategies

• For Diverse Learners:

  • Scaffolded worksheets with step-by-step instructions and visual aids.
  • Use of group discussions to verbalise understanding.
  • Provide simplified datasets or use physical manipulatives for kinesthetic learners.
  • Encourage bilingual explanations or use of Te Reo Māori terms for key concepts.

• For Advanced Learners:

  • Extension activity using digital phylogenetic tree software or constructing trees from genetic sequence data.
  • Explore implications of evolutionary relationships for conservation biology or speciation debates.
  • Task: Critique different types of phylogenetic trees and discuss limitations and assumptions.

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Mātauranga Māori Integration

• Incorporate the concept of whakapapa (genealogy) as a parallel to phylogenetic trees, emphasising interconnectedness and relationship to all living things.
• Discuss traditional Māori knowledge of biodiversity and how these genealogies reflect connections between species and the environment.
• Use local examples of native species and their whakapapa in discussions about species relationships.

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Assessment

• Formative assessment through observation and questioning during group activity.
• Evaluate students’ constructed phylogenetic trees for accuracy and reasoning.
• Reflection on success criteria verbally or via quick written exit slips.
• Optionally, assign an extended written analysis of a phylogenetic tree for deeper assessment.

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Teacher Notes

• Clearly highlight the visual literacy required to interpret trees; many students find this challenging initially.
• Emphasise evolutionary relationships as hypotheses constructed from evidence, not absolute truths.
• Reinforce how phylogenetic trees inform current biodiversity and conservation approaches in New Zealand.
• Use examples relevant to New Zealand’s unique biodiversity.

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Summary

This lesson provides Year 13 students a deep dive into evolutionary relationships through the active construction and interpretation of phylogenetic trees. It aligns with the New Zealand Curriculum’s emphasis on scientific thinking, literacy, and cultural connections through Mātauranga Māori, offering differentiated practices to engage all learners and extend the understanding of advanced students.

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If you want, I can also provide the scaffolded worksheet templates or suggestions for digital tools to build phylogenetic trees for this lesson.