Fig. 4.

(a) Distribution of CD in eukaryotic innovation domains (squares) and prokaryotic-only domains (circles). The data for these histograms are binned into bins of size 0.2. The CD is calculated as explained in Methods. (b) Distribution of TrC⁸ normalized by domain length in prokaryotic-only Dali domains (circles) and eukaryotic innovation domains (squares). The data were binned with bin size 4,000. Only domains with CD in the range between 3 and 4 are taken; 262 eukaryotic innovation domains and 843 prokaryotic-only domains fall in this range. The Kolmogorov-Smirnov (KS) P value for the null hypothesis that these two datasets were drawn from the same distribution is 0.001. For control, we randomly split prokaryotic-only domains ensemble into two equal parts and compared their distributions of TrC⁸. In contrast to comparison between eukaryotic innovation and prokaryotic-only domains, these two sets appear to be identical: KS P value for the same null hypothesis is 0.647.