Anthropologist: It was formerly believed that prehistoric Homo sapiens ancestors of contemporary humans interbred with Neanderthals, but DNA testing of a Neanderthal' s remains indicates that this is not the case. The DNA of contemporary humans is significantly different from that of the Neanderthal. Which one of the following is an assumption required by the anthropologist's argument? ['Any similarity in the DNA of two species must be the result of interbreeding.', 'The DNA of prehistoric Homo sapiens ancestors of contemporary humans was not significantly more similar to that of Neanderthals than is the DNA of contemporary humans.', 'At least some Neanderthals lived at the same time and in the same places as prehistoric Homo sapiens ancestors of contemporary humans.', 'DNA testing of remains is significantly less reliable than DNA testing of samples from living species.']