Er, no, not that kind of reproduction--academic reproduction. The most recent issue of the Journal of the Historical Society includes an article by Brendan McConville, "Early America in a New Century: Decline, Disorder, and the State of Early American History," which argues against current claims that early American history isn't sufficiently political or military enough. McConville concedes that the approach to politics and military history is different from that of a generation ago, but that nevertheless, "there may be more professional scholars studying military-related issues today than ever before" (467). "But you don't write about military-related issues," says the puzzled Gentle Reader. "You write about historical novels." There is that, yes. But I'm mostly interested in two of McConville's theories about shifting trends in historiography.
The first is that the students of some Eminent Historians have failed to give their parents scholarly grandchildren; as McConville notes, "[t]he students of Bernard Bailyn [...] have not gone on to replicate themselves by means of large graduate student empires, despite their prolific publishing careers" (463). Similarly, McConville estimates that "no more than twelve or so" of Gordon Wood's own graduate students are "active scholars" (463). He goes on to note that, by contrast, the numerous offspring of historians like Jack Greene have gone forth and multiplied. In other words, the shift towards cultural studies in early American history has partly to do with academic forces that cannot be reduced to simple political trends (or, as McConville tartly puts it, "Jack Greene as leftist cultural studies advocate--I know of at least ninety-two people who will get a laugh out of that" ).
It would be interesting to see a study of academic "descent" in English literature. For example, we might note the sudden emergence of doctoral dissertations on British periodicals during the 20s, 30s, and 40s. Who directed those dissertations? What careers did those students have? (One of them, Leslie Marchand, went on to write the still-standard biography of Byron.) And what students did they, in turn, produce?
Of course, it's rather difficult to "reproduce" yourself if you aren't at a doctoral institution. While McConville argues that "[t]he expansion of universities beyond the East Coast" (465) has reshaped the face of the profession , his insight could be pushed further: the black hole that is the job market, along with the oversupply of Ph.D.s, means that many students will spend their careers at liberal arts colleges, comprehensives, and other relatively teaching-centric schools. ("Like SUNY Brockport?" inquires my reader. Why, yes, now that you mention it.) These students will still publish, but few of them will see graduate students who intend to go on for doctoral work, and even fewer will direct a doctoral dissertation themselves. And adjuncts will almost certainly not be training anyone at all. It will be interesting to see how current academic career paths intensify some trends and disperse others.
 Dad the Emeritus Historian of Graeco-Roman Egypt, who called while I was typing, thinks that McConville is over-exaggerating here.