 A final noteworthy output of the HGP is what scientists learned about the structure of the genome. Beginning with the HGP, and building on further studies, researchers have gained a much more detailed picture of the fine structure, the dynamics and the functioning of the human genome. It was not only that there were many fewer genes present than expected, but there was also much more repetitive DNA and transposable elements present (it is estimated that about 45% of human DNA consists of transposable elements or their inactive remnants). These findings relate to a more general and older discussion about genome size and complexity to which we next turn.