Repetition of Research (Unintended)

Most of us are familiar with the classical narrative of ongoing scientific progress: that each new discovery builds upon previous ones, creating an ever upward-rising edifice of human knowledge shaped something like an inverted pyramid. There’s also an idea that, in the semi-distant past of a few hundred years ago one person could know all the scientific knowledge of his (or her) time, but today the vast and ever-expanding amount of information available means that scientists must be much more specialized, and that as time passes they will become ever more specialized. There is some truth to these ideas, but there are problems as well: when new knowledge is created, how is it added to the edifice? How do we make sure that future scholars will know about it and properly reference it in their own works? If a scientist must be incredibly specialized to advance knowledge, then what does he (or she) do when just starting out? How does one choose a field of research? And what happens when the funding for research into that area dries up? Contrary to what we learned in grade school, a scientist cannot choose to simply study, say, some obscure species of Peruvian moth and spend the next 40 years of summers in South America learning everything there is to know about it without also spending some time justifying that decision to colleagues and funding bodies.