Hierarchical clustering of gene expression in alewives from the Atlantic (AO) and Lake Michigan (LM) populations.

<p>Red color reflects overexpression in LM and blue in AO (intermediate expression is in yellow; lack of expression – in white). A total of 621 genes differentially expressed, genes at 8-fold change were used and Euclidean distance metric with centroid (fast) linkage method was implemented.</p>