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Quantitative Genetics Lab Exercise


The Precis coenia Quantative Genetics Lab is a computer program that guides the user through a laboratory exercise in estimating heritability. The specimens are real, drawn from a large experiment on the butterfly Precis coenia. Trait measurement on the wing pattern is quick and precise. Within a short time the user can capture the data needed to accurately calculate real heritability estimates.

Who is the lab intended for? The lab was designed with an undergraduate evolution course in mind. For pedagogical purposes, the actual heritabilities are not calculated by the program. Instead, the program outputs data on parents and offspring into an csv file, suitable for input into programs such as Microsoft Excel.

Who else might want to use the lab? Graduate Students and other Academics. The lab can be used for a graduate level course. To increase the challenge, students can combine measurements on different traits (taken during different measurement sessions) to estimate genetic correlations or even the G matrix. Students could also make sex-specific heritability estimates.

Researchers interested in the evolution of butterfly wing pattern, an excellent model system for studying both evolution and development, are free to use the specimen images and the digitizing program within the lab. With just a little bit of work, the lab can be used to digitize from the user's own images. Learn More

Preview: Want to see what the lab looks like before downloading it? Lab Overview


First a word about system requirements. The lab can run on Windows, Unix/Linux, and Mac platforms. Both the lab exercise and its installer were written using Java. This means that you will need the Java Runtime Environment (JRE) installed on your machine! This application requires Java JRE version 1.5.0+.

For installation in Windows, follow the Detailed Instructions (or just click on the download button and wing it). For installation in Unix/Linux, Java must be in the system path, and the installation program can be launched with the command "java -jar pcqgl.jar".

Clicking on either link below will start the installation process on your machine.

Download PCQG Lab Version 1.0 for Windows/Unix - Created 04/18/2006 - ~65Mb.

Download PCQG Lab Version 1.0 for Mac OS X - Created 05/25/2007 - ~65Mb.

Caution must be applied while running the lab on a Mac. While the user cannot resize the lab's window while it's running in either Windows or Unix, it's possible to resize the lab window on a Mac. Unfortunately, if the user does so while the program is running, the measurement points will not rescale and translate with the images. Thus care must be taken once the application frame is set to a given size that it be kept it at that size.

The download may take a while -- in addition to the program, over 1000 wing images are included!


The lab was created by John Corn, Jeff Gula, and Tae Lerch for a software engineering class, COMP 145 , in the Computer Science Department at the University of North Carolina at Chapel Hill. Project specifications were provided by the client, Susan Paulsen.

Impetus for the project came from Joanna R. Vondrasek who has developed a web site designed to provide outlines of laboratory exercises for undergraduate evolutionary biology courses. Laboratory Exercises in Evolution.

Images of the wing specimens were provided by Susan Paulsen. The specimens were drawn from a larger experiment conducted for her doctoral dissertation.

Miscellaneous Links

Old version of lab. Required the actual specimens.

Quantitative Genetics Lab Development Site. Lots of details about this project here.

Problems, questions? Contact
Susan Paulsen
Department of Computer Science
University of North Carolina at Chapel Hill
E-mail: paulsen at