From The New York Times:
And yet speculation is an essential part of science. So how does it fit in? Two recent publications about the misty depths of canine and human history suggest some answers. In one, an international team of scientists concludes that we really don’t know when and where dogs were domesticated. Greger Larson of the University of Durham, in England, the first of 20 authors of that report, said of dog DNA, “It’s a mess.” In the other, Pat Shipman, an independent scientist and writer, suggests that dogs may have helped modern humans push the Neanderthals out of existence and might even have helped shape human evolution. Is one right and the other wrong? Are both efforts science — one a data-heavy reality check and the other freewheeling speculation? The research reported by Dr. 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 Dr. 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. But how is one to judge the value of speculation? 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?
More here.