In order to reduce the risk of misclassification, we further restricted the analysis to Pfam families of viruses-metazoa (with $3 Pfam domains) that contain at least 2 viral proteins (total of 50 families). The length of the viral proteins is significantly reduced. For 90% of these families (above the reference line, Figure 5C ), the viral proteins are shorter than their matched metazoan proteins. In order to determine whether the reduction in length is due to a reduction in the number or the properties of the domains, we repeated the analysis for the ratio of the number of distinct domains (depicted by the different colored rectangles, Figure 5B) in the viral and their relevant metazoan sequences ( Figure 5D ). For 80% of the families (families above the reference line), number of different Pfam domains that are associated with viral proteins is reduced. Note that by this measure, a short viral protein ( Figure 5B a-b) still has a ratio of 1.0. We show that the viral proteins are not only significantly shortened, but have also converged to a simpler domain composition.