The title seems like a no brainer, of course they develop. Defensive end is a position that requires adjustment to the size and speed of NFL offensive tackles and thus, sack numbers usually don't rise until a player's 2nd, 3rd or sometimes even 4th year in the league.
When the Jaguars drafted Central Arkansas DE Larry Hart and Murray State DE Austen Lane in the 5th round of the 2010 draft, most believed they were good prospects to develop and possibly turn into sack masters of the future. One season later it seems as if those hopes have dwindled to some degree and many Jaguars fans were disappointed to see the team not add a premium pass rusher in the 2011 draft.
But looking at the development of prior 5th round and late round defensive ends, who's to say they wont break out in the near future? Or even as soon as the 2011 season?