The genome is full of retrovirus remnants, so there’s a way for a parasite to piggyback on the host genome. Alu repeats in human genome are one such example. Bu

The genome is full of retrovirus remnants, so there’s a way for a parasite to piggyback on the host genome. Alu repeats in human genome are one such example. But there’s a hypothesis that these get “domesticated” by the genome and start serving a function.