Number of pseudogenes per paralogous family. Pseudogenes were associated with paralogous families, based on their parents. Families discussed in the text are labeled with their number and the name of the associated Pfam domain, if characterized. BTB-MATH: Bric-a-Brac/Tramtrack/Broad Complex and Meprin and TRAF homology domain. DUF: domain of unknown function. The straight line represents the linear regression of the number of pseudogenes per family over the number functional genes per family. In the inserted plot, the y-axis has a greater range to represent family 3724.