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Evolution and Plasticity in Guppies

How Genes and Environment Shape Phenotypes


Author(s)

E. Dale Broder
Department of Biology
Colorado State University
EDaleBroder@gmail.com
Corey A. Handelsman
Department of Biology
Colorado State University
CHandelsman@gmail.com
Cameron K. Ghalambor
Department of Biology
Colorado State University
Cameron1@colostate.edu
Lisa M. Angeloni
Department of Biology
Colorado State University
Angeloni@colostate.edu

Abstract

This case study focuses on the relationship between evolution and plasticity using a hands-on, inquiry-based approach. Students view examples from the literature that illustrate the difference between nature and nurture, or the relative contributions of genes and the environment in shaping phenotypes. Using the Trinidadian guppy system as an example, students learn about seminal work in the field in addition to exploring quantitative genetic techniques used to partition phenotypic variance between genes (G) and the environment (E). They use real data from one of the publications cited in the case to graph reaction norms illustrating GxE interactions at the family and population level. The inquiry-based approach means that students are introduced to new concepts in a stepwise fashion, and asked to develop and build their understanding using causal, explanatory evidence. The case concludes with an exercise in which students apply their knowledge to a real conservation problem in Trinidad and Tobago, where guppies are native. This case would be appropriate for an upper level biology, genetics, or evolution course.


Objectives

  • Define evolution and plasticity.
  • Understand how quantitative genetics allows us to tease apart the influence of genes and the environment in shaping phenotypes.
  • Improve skills in graphing real data, interpreting figures, and summarizing major findings.
  • Recognize that a better understanding of the interaction between genes and the environment in shaping phenotypes can be informative in applied situations.
  • Develop policy recommendations based on scientific findings.

Keywords

Evolution; nature versus nurture; quantitative genetics; fish; common garden experiment; phenotypic plasticity; Trinidadian guppy; reaction norm; GxE

Topical Areas

N/A

Educational Level

Undergraduate lower division, Undergraduate upper division, Graduate

Format

PDF, Excel

Type / Methods

Analysis (Issues), Interrupted

Language

English

Subject Headings

Biology (General)  |   Evolutionary Biology  |   Ecology  |   Genetics / Heredity  |   Science (General)  |  


Date Posted

5/24/2016

Teaching Notes

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Teaching notes are intended to help teachers select and adopt a case. They typically include a summary of the case, teaching objectives, information about the intended audience, details about how the case may be taught, and a list of references and resources.

Supplemental Materials

The Excel spreadsheet below contains data for completing the exercise in Part III of the case.

  
  guppy_genes.xlsx

Answer Key

Answer keys for the cases in our collection are password-protected and access to them is limited to paid subscribed instructors. To become a paid subscriber, begin the process by registering.

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