Contemporary VCE BiologySection 2: Phylogenetic trees ⟩ Module 2:
How to represent relatedness between species?
The second module within Section 2 focuses on applying student understanding on phylogeny to construct a phylogenetic tree using the data provided that has been adapted from modern research. This module is expected to take 1 hour of class time.
Summary
VCE Biology (2017-2021)
Unit 4, Area of Study 1, Outcome 1, VCE Biology Study Design
Key knowledge
Determining relatedness between species
- Molecular homology as evidence of relatedness between species including DNA and amino acid sequences, mtDNA (the molecular clock) and the DNA hybridisation technique.
- The use of phylogenetic trees to show relatedness between species.
Duration
1 hour
Student learning outcomes
On completion of this module, students will:
- Apply their understanding on phylogeny to construct a phylogenetic tree
- Understand how phylogeny can inform decisions made by industries and that address conservation issues
Teacher background information
Module description
There are many conventions when constructing a phylogenetic tree that are often misinterpreted by students. During the sequence outline, some of the misconceptions related to interpreting phylogenetic trees were pointed out. It is suggested that they are addressed directly through student assessment and teacher clarifications.
In this final module, students are going to apply their understanding of phylogenetic trees by building two of them, using morphological data in the first activity and molecular data in the second. The latter was designed in the context of recent research developed by Deakin University, following up on the subject of plants with medicinal properties. The module ends with a final interview video with the PhD researcher whose project inspired this learning sequence.
Additional Information
Website
Building a phylogenetic tree (Khan Academy)
An engaging, student-friendly explanation of how to build phylogenetic trees. It shows how to plot morphological traits in a tree and what they mean, and it also explains the idea of parsimony as it is applied in phylogenetic studies. In a previous section in the same website you can also find details about phylogenetic trees, breaking them down into simple parts that make them easier to read while addressing common misconceptions.
Website
Trees, not ladders
Webpage addressing one of the biggest misconceptions about phylogenetic trees. Focused on the idea that organisms to the right of the tree are “more advanced” or have descended from the groups of organisms to the left, the webpage offers a simple explanation of the organisation of phylogenetic trees, which can be shared with students.
Video
Creating a phylogenetic tree (8:50)
A step-by-step tutorial on how to build a phylogenetic tree using molecular data from the Oxford University Press (October, 2017).
Teaching sequence
Lesson 1 Applying student understanding on phylogenetic trees
1 hour
Student knowledge/ skills outcome
Students will be able to:
- apply their knowledge on reconstructing phylogenetic trees from molecular and morphological data
- identify some of the applications of research in phylogeny to the modern society
Prior Knowledge
- previous modules completed
Activities
Activity 1
Building a phylogenetic tree (20-25mins)
https://bioenv.gu.se/digitalAssets/1580/1580956_fyltreeeng.pdf
This article contains instructions to conduct an introductory activity to construct phylogenetic trees. It is recommended that students undertake this activity in small groups to allow for discussion. The activity allows for the construction of a phylogenetic tree using morphological traits only. The teacher should guide the students to use parsimony when developing trees, choosing the one that explains relatedness between all organisms in the shortest evolutionary pathway.
Activity 2
Phylogeny and its applications (20-30mins)
- Student handout: section2-module2-phylogeny-and-its-applications–student-handout.pdf (296KB pdf)
- Teacher copy: section2-module2-phylogeny-and-its-applications–teacher-copy.pdf (296KB pdf)
This designed activity was inspired by current research in phylogeny and shows some of the applications to modern society. More specifically, the activity addresses the interest of the pharmaceutical industry in finding a species with the greatest likelihood of presenting medicinal properties, which can be inferred from its relatedness to known medicinal plants. Students can use the supporting information below to learn more about the Tasmanian mountain pepper, the activity’s protagonist. Additional information can be found on other plants used by Aboriginal communities in south-eastern Australia, a valuable source of ethnobotany and celebration of Aboriginal knowledge.
Supporting resources
Article
Factsheet about the Tasmanian Mountain Pepper (78KB pdf)
This article contains instructions to conduct an introductory activity for the construction of phylogenetic trees. It is recommended that students undertake this activity in small groups to allow for discussion.
Article
Tasmanian mountain pepper harvest in full swing at Underwood
ABC news report on the Tasmanian Mountain Pepper, outlining its economic importance and rarity.
Activity 3
Implications for conservation decisions (5-10min)
Extending on the applications of phylogeny, teachers may promote a discussion on how knowing the relatedness between organisms may impact on conservation issues. Students may discuss this in pairs and then share their conclusions in a whole-class discussion.
Video (12:29)
Uday Sundara (Deakin University)
In this final interview, PhD student (as of January 2018) talks about her research project in phylogeny and what her main activities as a researcher were. She summarises some of her main results and their possible implications to the pharmaceutical industry and conservation decisions. This is an excellent opportunity for students to learn more about the daily activities of a researcher and break some stereotypes about research activities. As opposed to what some students might expect, not all researchers spend their days doing lab work. This interview also wraps up student learning on what phylogeny is and what research in phylogenetics is for.
