Comparison of Results between the EM algorithm (θ = 100) and a Previous ML Method 
The results of the EM algorithm when using θ = 100 are shown. Numbers in parentheses indicate the differences between the two results using our results as the benchmark. Numbers of introns present in modern species (known) are in black. Numbers of introns present in ancestors (estimated) are in green. Numbers of gains and losses (estimated) for each branch are in red and blue, respectively. Branches that experienced >1.5 gains per loss are shown in red, and those that experienced >1.5 losses per gain are in blue. D.mel, D. melanogaster; A.gam, A. gambiae; C.ele, C. elegans; H.sap, H. sapiens; S.pom, S. pombe; A.tha, A. thaliana; P.fal, P. falciparum.