Borna virus is not a retrovirus. It doesn't actually insert its own genes into our cells. What it does is just hangs out near our DNA and uses some of the molecular machinery to copy itself.
Carl ZimmerThere is some research that suggests that viruses like the flu are really actually kind of at the razor's edge when it comes to mutation. They're mutating so fast that if they mutated much faster they would actually develop a lot of harmful mutations that could slow them down and cripple them and eventually literally drive them extinct.
Carl ZimmerIt used to be thought that only a certain kind of virus could get into our genome and it's called a retrovirus and that's a virus that might be HIV for example.
Carl ZimmerWe have Borna virus genes. We're part Borna virus, which is weird, but apparently our cells and our genomes in a weird way might actually be grabbing these viruses, grabbing genetic material from the viruses that are infecting it and pulling them into their own genome.
Carl ZimmerResearchers keep identifying new species, but they have no idea about the life cycle of a given species or its other hosts. They cut open an animal and find a new species. Where did it come from? What effect does it have on its host? What is its next host? They don't know and they don't have time to find out, because there are too many other species waiting to be discovered and described.
Carl Zimmer