These days many (probably most, though I don't have that kind of data) research universities are moving away from intro classes taught by tenured faculty. It's

These days many (probably most, though I don't have that kind of data) research universities are moving away from intro classes taught by tenured faculty. It's more common to have non-tenure track faculty teach intro classes, along with the tenured faculty that enjoy doing it. Interestingly, I've heard many complaints about tenure based on complaints about non-TT faculty.