How much do scientists know and how much do they guess at, asks The New York Times' James Gorman. It may seem counterintuitive, but speculation in science is important, he says, and does have its place among the facts and data. For an example, Gorman cites two recent studies about dogs in human history — one of which looked at the dog genome and concluded that no one really knows when dogs were domesticated and the other of which used speculation to suggest that dogs may have helped modern humans become dominant over Neanderthals. "Is one right and the other wrong? Are both efforts science — one a data-heavy reality check and the other freewheeling speculation?" Gorman says. "The research reported by [the University of Durham's Greger] Larson and his colleagues in The Proceedings of the National Academy of Sciences is solid science, easily judged by peers, at any rate. The essay by [independent scientist Pat] Shipman is not meant to come to any conclusion but to prompt thought and more research. It, too, will be judged by other scientists, and read by many nonscientists."
Perhaps the value in speculation is not whether it is right, but whether it inspires others to ask more questions and do more research, Gorman adds. "The questions readers ought to ask when confronting a 'what-if' as opposed to 'what-is' article are: Does the writer make it clear what is known, what is probable, and what is merely possible?" he says.