Quote: " ... though not the principle [sic] cause, argues Prof Adrian Lister of the NHM."<p>Principle, not principal? This comes from a science correspondent, a professional journalist who works for the BBC.<p>I am astonished -- children are becoming students and students are becoming adults, taking on professional responsibilities in the communications arts, fields where print literacy is central to one's ability to function. And these people don't know the difference between "principle" and "principal"?<p>In modern times, homonym confusion usually results from spending too much time listening to words, and too little time reading them. For a print journalist, this is not an excuse.