A headline in a recent edition of the New Zealand Herald caught my eye: "Revealed: a dino's bugbear". The article kicks off: Biting insects might have killed off the dinosaurs, rather than a cataclysmic meteor impact, a new theory claims. Scientists now say disease spread by ancient mosquitoes, mites and ticks was probably the major factor that finished off the extinct reptiles. Gosh! (Said in a somewhat cynical manner…)
OK, so they're using theory to mean an idea or hypothesis, rather than the scientific meaning of a coherent explanation for a large number of facts and observations about the natural world. It's a widespread usage, though I don't have to like it! What annoys me more is the phrase, scientists now say. This suggests there's a scientific consensus on the issue, and I don't think that's the case at all.
Why not? Because the article is not reporting on a peer-reviewed publication: a scientific paper that's been critiqued by other scientists (in a rigorous process) prior to its acceptance for publication in a journal. It's based on ideas presented in a new book aimed at a general readership. The books' authors have published fairly extensively in the fields of detecting ancient DNA (dino DNA, among others) and of palaeo-parasitology (you'd expect dinosaurs to have various parasites, & it's really neat to see evidence of them), But I couldn't find any papers putting forward this hypothesis directly, although a couple hinted at it. So, to date, it's not an idea with widespread scientific acceptance. But it is an interesting hypothesis.
In other words, view the statement 'scientists say' with a certain amount of caution. Who says [whatever the journalist is writing about]? How many scientists say it – is it really a consensus, or a new idea put forward for consideration & future research? And what forum are they saying it in?
The article raises some interesting evolutionary issues, too, but I think I'll come back to them in another post.