Ordering/reordering project entries

[juniperover]

I've adapted the "projects" page type to create pages for my lab group and for collaborators--both of these are collections of pages for individual people, with "title" as people's names, and "excerpt" giving a line about them. Then their bios appear on their individual page.

These seem to be presented on the main page (__index.md) in the order in which I edited them...I'd like to order them alphabetically. Is there a way to force this? Thanks for any help!

Edited: They are presented in alphabetical order by the people's first name. I've named each page folder with surname first; is there a way to force alpha by that name instead of the title? Thanks!