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Si el Norte Fuera el Sur

A Case of Squirrel Monkey Identities


Karin Gastreich
Biology Department
Avila University


In this case study, students are given the task of developing a recovery plan to protect a recently discovered population of Central American squirrel monkeys on the Pacific Coast of Costa Rica. In the process they must determine whether the population is a separate species or related to another species of monkeys in the area. The case was originally designed for a course on fundamentals of tropical biology. The activity is adapted from another case study in the NCCSTS case collection: "Trouble in Paradise: A Case of Speciation" by James A. Hewlett. Due to the open-ended nature of the activity, there is no separate answer key for this case.


  • Review and consolidate their background understanding of evolutionary processes that give rise to speciation.
  • Apply concepts of micro- and macro- evolution to the divergence of two populations of Central American squirrel monkey.
  • Interpret simple data about squirrel monkeys, make inferences, and draw conclusions from that data.
  • Produce an original evolutionary story about the divergence of two populations of squirrel monkeys, using actual and fabricated data.
  • Learn the geography of southwest Costa Rica and understand the role of geography in generating species diversity.
  • Understand the concept of species and the implications of this concept for conservation.
  • Work cooperatively in small groups to develop skills in creative problem solving.
  • Develop a collaborative relationship with fellow students in an academic and social environment.


squirrel monkey; speciation; tropical forest; population recovery; directional selection; stabilizing selection; Ballena Marine; Costa Rica; Saimiri oerstedii

Topical Areas


Educational Level

Undergraduate lower division, Undergraduate upper division



Type / Methods




Subject Headings

Biology (General)  |   Ecology  |   Zoology  |   Wildlife Management  |   Evolutionary Biology  |  

Date Posted


Teaching Notes

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