Our DNA contains the functional instructions for all of our cells, from the cells in our brains to the cells in our bones and our blood. But it is only by activating and deactivating different segments of our DNA, or our genes, that our cells take on their specialized functions.
This is true for all sorts of organisms, whose cells are differentiated when different genes are switched on and off. In simple organisms, these on-off “switches” are typically situated only a short distance away from the genes that they activate and deactivate. But in complex organisms, these switches are sometimes separated from the genes that they regulate by long lines of DNA letters, sometimes numbering in the tens of thousands.
Recent research has found, however, that this long-distance form of gene regulation is actually a lot older than once thought. Published today in Nature, the research reveals that these distant on-off switches likely appeared early on in the evolution of animals, around 700 million years to 650 million years ago, or about 150 million years earlier than previously estimated.
