Counting Critters: Using the Paleobiology Database to track fossil diversity through geologic time
Skills and concepts that students must have mastered
- Define Linnaean taxonomy terms: family, genus (Part 1)
- Define the terms "linear" and "exponential" (Part 1)
- Understand that organisms (plants and animals) didn't invade land (terrestrial ecosystems) until after the Cambrian (Part 1)
- Think about two time intervals that have been particularly well sampled (e.g., intervals with population organisms like dinosaurs, intervals with major extinctions)(Part 2)
- Think about two groups of organisms that are likely to have a well-preserved fossil record (e.g., organisms with bones or shells)(Part 2)
- Define the term "taphonomy" (Part 2)
- Use Microsoft Word to fill out answers in document (all parts)
- Interpret basic graph features (all parts)
How the activity is situated in the course
Content/concepts goals for this activity
Higher order thinking skills goals for this activity
▪ Construct a diversity curve using data and tools from PBDB Navigator (Part 1)
▪ Interpret graphical representations of diversity curves to identify possible increases and decreases in diversity (Part 1)
▪ Identify a major origination (Cambrian Explosion) graphically and use internet sources to research its possible causes (Part 1)
▪ Identify a major extinction (end-Permian Extinction) graphically and use internet sources to research a possible cause.
▪ Assess the effects of sampling and preservation on quantifying diversity (Part 2)
▪ Assess the extent to which diversity patterns are affected by the inclusion of singleton taxa (Part 2)
▪ Determine the extent to which Pull of the Recent is influencing diversity patterns (Part 2)
Other skills goals for this activity
Description of the activity/assignment
This activity is designed to be flexible and can be used as a lecture, lab, or homework activity. It is divided into two parts and can be modified by picking and choosing which parts (and which questions within parts) to include. The duration of the activity ranges from 10 minutes to three hours, depending on which parts are assigned.
Students can work as individuals or in pairs and class size can range from a small seminar (< 10 students) to a large lecture (> 100), as long as sufficient computer facilities are available.
Each student or student pair will need access to a laptop or desktop computer connected to the internet, running both Microsoft Word and an internet browser.
Determining whether students have met the goals
Can be accomplished in lecture or lab by observing student progress and trouble-shooting challenges. Can also doublecheck that the major tasks (i.e., constructing correct diversity curve, circling increases in diversity, starring decreases in diversity, researching the Cambrian Explosion, research the end-Permian extinction) are accomplished in a timely manner and are accurate.
Key summative assessment points include: the graph of diversity, identifying increases and decreases on this graph, describing two possible drivers of the Cambrian Explosion, and describing one possible cause of the end-Permian extinction. Instructors can use the answer key provided to assess students' understanding of the main concepts. Summative assessment can also be included as midterm and final exam questions focusing on the key summative assessment points listed above.
Download teaching materials and tips
- Activity Description/Assignment: Student handout for "Counting Critters" (Microsoft Word 2007 (.docx) 67kB Jul20 17)
- Instructors Notes: Instructor notes for "Counting Critters" (Microsoft Word 2007 (.docx) 160kB Jul20 17)
What is a diversity curve?
Major events in the history of life
End-Permian extinction event
How to develop hypotheses