Vision Statement

The Virtual Genetics Lab (VGL) is a simulation of transmission genetics that approximates, as closely as possible, the hypothesis-testing environment of genetics research.  In this lab, students cross hypothetical creatures and examine the progeny in order to determine the mechanism of inheritance of a particular trait.  As in actual research, it is not possible to 'see the answer' - the student must decide for herself when she has collected enough data to be sure of her model.  The goal is to have students understand the logic of genetic analysis - how one can use crosses to determine how a trait is inherited and reinforce their understanding of transmission genetics.

There are two versions of the Virtual Genetics Lab: VGL and VGL II.

VGL

VGL presents students with problems involving one gene only.

VGLII

VGLII presents students with problems involving one to three genes and linkage.

These programs are based on the Genetics Construction Kit (GCK) developed by BioQUEST. The original GCK was written in the mid-1980's and ran on the Macintosh Classic operating environment. VGL is designed as a newer version of GCK that is compatable with Windows and Unix-based operating systems and that takes advantage of the improved user interface available on newer computers. GCK includes some features that VGL does not (problems involving multiple genes, linkage, etc.). A new version of GCK is expected soon; check the BioQUEST website for updates. A comparison of some key features of VGL and GCK is shown at the bottom of this page.

In order that the exercise is based on the logic of genetic analysis rather than student's ability to search the internet, the creature under study will be hypothetical, the traits will be assigned randomly, and the mode of inheritance will differ with each run of the program.  Traits can be either autonomic or sex-linked (with XX females and XY males or with ZZ males and ZW females) and simply dominant or co/incompletely dominant.  The form of the trait which is dominant, recessive or seen in the heterozygote will also be determined randomly.  The instructor can customize the program to limit the range of possibilities that the students could face.  In this way, students can be gradually introduced to problems of increasing complexity.

In a real genetics lab, students have to deal with real-world creatures that die, fail to mate, or escape.  In addition, most creatures have generation times of several weeks or months, thus limiting the number of crosses an individual can perform during a semester.  Although these real-world constraints have educational value, the point of the VGL is to understand the logic of genetic analysis rather than the technical details.  The VGL will allow the students to maximize the number of crosses they can perform, thus maximizing their chance to understand the underlying analysis.

In this lab, students have to decide:

In order to perform a cross, the students select male and female parents of their choice from any generation and click the "Cross" button.  The program keeps track of the genotypes of the parents and generates their offspring probabilistically.  In that way, the phenotypic ratios of the offspring will approximate, but not necessarily be identical to the classic 1:1, 1:2:1, and 1:3 ratios.  The students have to decide for themselves whether their data are consistent or inconsistent with their expected ratios.  While some crosses will generate useful information, others will be uninformative; the students will have to choose what to cross and what to make of the results.

Cross results are presented in a table sorted by phenotype with a display of the numbers of male and female individuals of each phenotype.  In addition, a thumbnail image in the table gives a visual display of the phenotype.

Because of this freedom to choose what to cross, different student groups will adopt different strategies for analysis.  Some will plan each cross carefully and analyze the results as they go along while others will do many haphazard crosses and try to sort out the results later.  VGL thus accommodates the wide range of successful strategies and does not limit the students to one particular pattern.

Although VGL is designed so that students cannot 'look behind the scenes' to see the underlying model or the genotypes of individuals, the instructor can generate problems in 'practice mode'.  In this mode, students are able to click on individuals and see their genotypes as well as the underlying genetic model.  This mode is designed for the beginning students to help familiarize them with the program and the most basic genetic analysis.

Finally, the program has several important software features:

VGL has been used by over 350 biology students a year at UMass Boston.

VGL was designed and developed by a team of four Master's degree students in Computer Science at UMass Boston and Brian White.

There are two versions of VGL: VGL and VGLII. A ccomparison of these two programs and GCK is shown below.

Comparison of VGL, VGLII, and GCK

Program Compatible OSs Genes per problem Sex-linkage User Interface Phenotype Display Price
VGL -Win98 & up
-UNIX/Linux
-Mac OS 10.1 through 10.5
 One only XX/XY & ZW/ZZ Color Color images Free
VGL II -Win98 & up
-UNIX/Linux
-Mac OS 10.1 through 10.5
 1 to 3 only XX/XY & ZW/ZZ Color Text only Free
GCK Mac OS 6 thru 10.3 1 to 3 XX/XY only Black & white Text only Nominal charge