Going to the Dogs: Exploring Allometry and Heterochrony
This activity has benefited from input from faculty educators beyond the author through a review and suggestion process.
This review took place as a part of a faculty professional development workshop where groups of faculty reviewed each others' activities and offered feedback and ideas for improvements. To learn more about the process On the Cutting Edge uses for activity review, see http://serc.carleton.edu/NAGTWorkshops/review.html.
This page first made public: Jul 22, 2009
Skills and concepts that students must have mastered
- Understanding of basic processes and terminology associated with heterochrony
- Basic graphing skills
How the activity is situated in the course
Content/concepts goals for this activity
- isometry and allometry (positive vs negative)
- macroevolutionary processes
Higher order thinking skills goals for this activity
Other skills goals for this activity
Description of the activity/assignment
In Part A, students begin the activity by measuring skull length vs. braincase width in an ontogenetic sequence of an "ancestral" wolf species. They graph the resulting data then determine whether the relationship between the two is isometric or allometric.
In part B, they choose three skulls of adult domestic dog breeds (available via online sources such as Skulls Unlimited). Measure the same two variables and compare these "descendent" data to the wolf "ancestral" data. In this way, they determine which dog breeds (e.g., pugs, bulldogs) appear to be paedomorphic and which (e.g., greyhounds) appear to be peramorphic.
Determining whether students have met the goals
Download teaching materials and tips
- Activity Description/Assignment:Student handout for Going to the Dogs (Microsoft Word 1.6MB Jul22 09)
- Instructors Notes:
- Solution Set: