The Great Clade Race - Zombie Island Edition

I use this in my "Life Through Time" course (a freshman history of Life class in Geology/Geoscience). It would work in a high school class or any undergraduate paleontology/Evolutionary biology class.

This is a pretty good entry-level activity, but a short lecture about cladistics is a good way to lead into this activity. You could also have students lump the cards into groups before running the activity based on characteristics of their choosing (number of colors, number of symbols, etc.), in order to set up a discussion of cladistic versus non-cladistic classification schemes.

It could be done as an active learning activity in a class or during lab as it usually only takes ~20-25 minutes.

From Goldsmith (2003): "For many students, an introductory lecture on cladistics comes across as an onslaught of strange new terms and opaque jargon. By the time they have even begun to learn the meaning of words like "synapomorphy," "homologous," and "parsimony," many of them have already reached the conclusion that cladistics is something so complex that they simply cannot understand it. Once a student arrives at this conclusion, it is particularly difficult to lead him or her past it. I have developed a simple puzzle to begin my introductory cladistics lessons that allows students to use cladistic thinking without first bogging them down with terminology. In classes where I have used this exercise, which I call the Great Clade Race, students not only begin their approach to cladistics with a more positive attitude, they also seem to have a better comprehension of what cladistics does and why cladistics is used."

Analyzing data, evaluating models, synthesizing observations, and deductive reasoning/logic.

Working in groups, diagramming results, and deductive reasoning/logic.

Phylogenetic Systematics Analogy - Zombie Island

Activity Description (Acrobat (PDF) 1.3MB Jul20 20)

Instructions Power Point (PowerPoint 2007 (.pptx) 4.1MB Jul20 20)

Student teams are forensic scientists (like in CSI) trying to reconstruct the events on Zombie Island based on clues from survivors. Working in a group of 3-4, you'll turn in one piece of paper for your group with all of your names on it. You have a set of 8 cards with symbols on them; these cards are your clues! Cards 1-9 (Acrobat (PDF) 96kB Jul13 20)

Use logic to reconstruct everyone's escape route based on the clues found on their cards and the following rules:

1. Zombies infested this island, the island people had to get away, so they ran to the beach to swim to safety!

2. They left the stronghold by a single exit.

3. The only safe way off the island was the northern beach

4. They escaped from anywhere on the northern side of the island

5. They could not retrace their path or go back (zombies!!!)

6. People ran through the woods in groups or split up

- People either stayed with their group or split in two
- People never (re)joined a group (they might be zombies!)

7. Each person has a card that captured pollen from plants

8. As they ran, each person passed vegetation with unique pollen that got stuck to their card.

9. Everyone made it to the beach!

Student Handout (Acrobat (PDF) 678kB Jul13 20)

Deliverable #1: Using the sticky cards collected from the survivors in the water:

- Sketch the paths of escape from Zombie island
- Show all patches of vegetation people passed through (on the straightaways)
- Mark the beach exit used by each person

Deliverable #2: Compare your map with another group's map; do they look identical? If not, does their map still work (i.e., can maps that look different represent the same data)?

Optional Deliverable #3: If you finish early, your instructor will give you a ninth card. Add this survivor to your map. Do you encounter any problems? What might these issues tell you?

Students may initially doubt that they have enough information to complete the assigned task. The hint in slide #13-14 of the attached PowerPoint is very helpful in helping them see what they need to do.

Discuss cladistics terminology with the students and ask them to identify what parts of the activity represent synapomorphies, (sym)plesiomorphies, and autapomorphies (see hint on slide 19 of the attached PowerPoint). Ask students to identify the assumptions that went into their model. What new assumptions did they realize they had made after working with the ninth card (see hint on slides 21-25 of the attached PowerPoint)?

The Great Clade Race
Author(s): David W. Goldsmith
Source: The American Biology Teacher, 65(9):679-682. 2003.
DOI: 10.1662/0002-7685(2003)065[0679:TGCR]2.0.CO;2