Less than 2 per cent of our genome is actually coding. The rest of the genome is a veritable graveyard of “junk”, consisting of old genes that have lost their function, repetitive strings of DNA whose function is not fully understood, and various other recognizable repeat elements. One such element is a virus; to be specific, something we call endogenous retroviruses (ERVs), which have managed to insert themselves into our ancestors’ DNA in the distant past, millions of years ago.
Why do we bother to look at these bits of DNA that are ancient, with no function—what’s the point? These integrated viruses are the equivalent of fossils in our genome—they provide a record of what has happened in our genome, and looking at these “fossil viruses” allows us to better understand how our genome (or any genome for that matter) has evolved.
Read the full, original story here: Women in Science: Genome Invaders – Friend or foe?