Introduction
Conclusions
Prosser Dam
Resident Trout
SH Population
Roza Dam SH
1) Compare a 2006 collection from Roza Dam to the previous
     collections from the upper Yakima
Roza Dam Steelhead
Project Objectives
Why?
Inferences about population dynamics based on genetic data
rely on accurately estimating allele frequencies
Possible explanations for temporal instability are:
 1) The population is experiencing genetic drift
 2) There is gene flow from a differentiated stock
 3) The collection itself is not a valid population sample
Current project
1) Inferences about population dynamics (e.g., census size fluctuations or hatchery introgression) based on genetic data rely on accurately estimating the frequencies of alleles observed.
2) Several recent genetic studies have reported inconsistencies in allele frequency estimates taken from a single population at multiple time periods, with some temporal variation high enough in magnitude to cause erroneous conclusions about population differentiation
3) If allele frequency differences are observed between temporally replicated collections from the same location, possible explanations for the result are the population is experiencing genetic drift, there is gene flow from a differentiated stock, or the collection itself is not a valid population sample.