September 24th 2012
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Objective: To begin the HWE simulation
Entrance Ticket
If you wanted to model HWE, what would
(should) the population look like?
What are some changes that you could
make in order to understand how
populations change?
Plan
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Notes – The Lab
Begin Simulation
Mathematical Modeling of a
Hypothetical Population
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“Mathematics is Biology’s next microscope,
only better” (Cohen 2004)
The Problem with HW
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It is the Null Hypothesis
HWE is what would happen to allele
frequencies without any evolutionary
parameters at work
The Problem With HW Simulations
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Classroom Population?
Genetic Drift takes over – makes it
impossible to see the effect of any other
evolutionary parameter
The Advantage of this Simulation
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Excel spreadsheet allows for randomness
Population size is no longer limited
You can look at allele inheritance patterns for
a theoretically infinite population in which
fluctuations from expected probabilities are
minimized
3 Phases of Investigation
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Model Building
Model Testing
Model Corrections as necessary
Model Building
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Demonstrates how a hypothetical gene pool
changes from one generation to the next
Allows for exploration of parameters that
affect allele frequencies, such as selection,
mutation, and migration
Model Testing
Your Task
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Create a spreadsheet to begin modeling a
population – everyone must have their own
spreadsheet to start
Begin developing a question that you want to answer
- this can be done with a partner or in your study
group
Due Wednesday – initial spreadsheet and question
See website tomorrow for resources and other
helpful links
Sources for Advanced Models
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The Supertaster Lab
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Google “ABLE proceedings + supertaster” to access the lab
There are few human traits that express the intermediate
dominance necessary for testing for the null hypothesis. The
supertaster trait described in this laboratory does express
an intermediate phenotype; therefore, it creates an
exemplary investigative population genetics laboratory.
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The Esteem Module - Deme 1.0 or 2.0 at
http://bioquest.org/esteem/esteem_result.php
[You’ll need to register for the site, but it is free.]
or Jon Herron’s Allelle1
http://faculty.washington.edu/herronjc/SoftwareF
older/AlleleA1html.
An alternative is an online Web browser-based
model at
http://www.radford.edu/~rsheehy/Gen_flash/popg
en/.)