What is the significance of the savages saying the chief has spoken Lord of the flies?

The savages saying "the chief has spoken" in reference to the Lord of the Flies highlights the growing influence of Jack and the primal instincts he represents over the group. It shows the diminishing power of reason and civilization, as they begin to turn towards violence and savagery. Ultimately, it symbolizes the descent of the boys into darkness and the loss of their humanity.