Why does merridew reject the name jack lord of the flies?

Merridew rejects the name "Jack" in an attempt to distance himself from his previous life and the rules of society. By adopting the name "Merridew," he is able to reinvent himself and embrace a new identity as a leader and hunter on the island. This rejection of his former name symbolizes his descent into savagery and his desire for power and control in the absence of civilization.