Early in Earth's history, Furons mated with Humans right after the Martian War, meaning every Human alive has pure Furon DNA. As said by Pox 13:" It was in the earliest days of the Empire we realized that our species was doomed. Eons of waging war on inferior races with unregulated atomic weaponry had mutated or genes, we could not propagate due to a complete and utter lack of genitalia. Fortunately, a Furon ship happened upon Earth on its way back from destroying the Martians. Human society was young and noble…sailors on a foreign planet, let off steam…one thing led to another. Long story short every human being alive today has buried deep in its genetic code a strand of Furon DNA".