How does Jack contribute to conflict in Chapter 2?

Jack contributes to the conflict when he breaks the rules, specifically, by interupting Ralph while he is speaking and inpossession of the conch

“That’s what this shell’s called. I’ll give the conch to the next person to speak. He can hold it when he’s speaking.”
“But–”
“Look–”
“And he won’t be interrupted: Except by me.”
Jack was on his feet.
“We’ll have rules!” he cried excitedly. “Lots of rules! Then when anyone breaks ’em–”
“Whee–oh!”
“Wacco!”
“Bong!”
“Doink!”
Ralph felt the conch lifted from his lap. Then Piggy was standing cradling the great cream shell and the shouting died down. Jack, left on his feet, looked uncertainly at Ralph who smiled and patted the log. Jack sat down. Piggy took off his glasses and blinked at the assembly while he wiped them on his shirt.
“You’re hindering Ralph. You’re not letting him get to the most important thing.”