... encode proteins, but make up the overwhelming bulk of large genomes - some 99%% in humans. A significant fraction of these sequences are pseudogenes, or fossils of ancient proteins, and although many of them are transcribed into RNA, they have hitherto been deemed 'junk'. Source: Nature http://www.nature.com/nature/journal/v453/n7196/full/453729a.html Posted by Robert Karl Stonjek