Technologically, neanderthal and modern man were equals until they died out. If walking on the moon is a measure of humanity, they you and I are not human. Neither of us have walked on the moon. In fact by this definition, there are only about 20 humans on earth. Tis sad to see so many people walking around deluding themselves that they are human.
Science often works by eliminating other possibilities.
There is nothing wrong with doing it that way. Christian explanations of fossil man are totally untenable and never, never talk details. I will answer that. Because most christians don't want to know the details because it harms their viewpoint.