Q: What’s the real deal on evolution? Twenty years ago on “Cosmos,” Carl Sagan said it wasn’t a “theory” but a “law.” My Christian friends tell me it’s a theory shot full of errors. And my scientist friends tell me it’s provable in the everyday world. A; Explanations of human evolution are not likely to move beyond the stage of hypothesis or conjecture. There is no scientific way – i.e., no experiment or other means of reliable study – for explaining how humans developed. Without a valid scientific method for proving a hypothesis, no indisputable explanation can exist. The process of evolution can be scientifically demonstrated in some lower life forms, but this is a far cry from explaining how humans developed. That said, some sort of evolutionary process seems most likely in my opinion. But there will probably always be enough uncertainty in any explanation of human evolution to give critics plenty of room for doubt.