Comparison of observed/expected tandem and segmental duplications for 50 large A. thaliana gene families Ratios of observed to expected tandem duplications in the 50 gene families in the study are shown on the vertical axis, and ratios of observed to expected segmental duplications on the horizontal axis. For purposes of discussion, one and two standard deviations around the means on each axis are shown with a box plot. Among families outside of one standard deviation, families with members that play roles in pathogen defense are indicated in red. Transcription factor families are shown in light green. Several housekeeping genes are shown in dark green. Several broad-function enzyme families are shown in brown. Notice the relative scarcity of gene families that are high in both categories, and eight families that have no apparent tandem duplications.