Table 1.

Total Size of All Five Data Sets Analyzed and the Percentage of Missing Data in Each

Data Set	Total Sites	% Missing
miRNAs	674,100	22
Nucleotide	770,794,920	39
Hallström and Janke (2010)	7,116,417	21
O'Leary et al. (2013)	522,790	8
Romiguier et al. (2013)	1,065,012	52