Servat takes the hooker's role from Raphael Ibanez, who, like Galthie, quit after the World Cup.
Pape moves into the second row after Jerome Thion was ruled out of the entire tournament through injury.
Laporte said: "No one has really staked a claim for the scrum half role behind Fabien Galthie.
"Jean-Baptiste now has his chance at international level as Dmitri Yachvili has had before."
France side to play Ireland: N Brusque (Biarritz); V Clerc (Toulouse), Y Jauzion (Toulouse), D Traille (Pau), C Dominici (Stade Francais); F Michalak (Toulouse), J-B Elissalde (Toulouse); S Marconnet (Stade Francais), W Servat (Toulouse), P De Villiers (Stade Francais), F Pelous (Toulouse), P Pape (Bourgoin), S Betsen (Biarritz), O Magne (Montferrand), I Harinordoquy (Pau).
Replacements: Y Bru (Toulouse), J-J Crenca (Agen), D Auradou (Stade Francais), T Lievremont (Biarritz), D Yachvili (Biarritz), B Liebenberg (Stade Francais), P Elhorga (Agen)