Recombination Calculations by Branch Diagrams
Gilliland and Michael G. Rosenbaum
This is a method for analyzing
recombination events in laboratories
focused on genetic recombination. As the
authors note, genetic recombination can
be difficult to understand because of
the abstract nature of the experiments
used to measure it. Thus, this
resource demonstrates how to use branch
diagrams to list all possible phenotypes
for the progeny and identify which
classes are recombinant, calculate the
expected phenotype frequencies from
known map distances, and use progeny
count data to calculate map distances
and interference. The branch diagram
method provides visual cues for which
classes are recombinant, as well as a
structural guide to assist students with
the mathematical analysis of
Genetics Concept(s) Addressed:
Nature of genetic material: What are the molecular components and mechanisms necessary to preserve and duplicate an organism's genome?
Transmission/patterns of inheritance:
How does the phenomenon of linkage
affect the assortment of alleles during
Core Competencies Addressed:
Students should be able to implement observational strategies to devise a question.
Students should be able to generate testable hypotheses.
Students should be able to design an experiment using appropriate controls and appropriate sample sizes.
Students should be able to gather and evaluate experimental evidence, including qualitative and quantitative data.
Students should be able to apply statistical methods when analyzing their data, and use patterns to construct a model.
Gilliland, William D.
and Rosenbaum, Michael G.
(2013). Recombination Calculations by
Branch Diagrams. Genetics Society of America
Peer-Reviewed Education Portal (GSA
Laboratory Justification and
Description for Instructors
Sample Data Sets