What was the central issue addressed by the highly publicized scopes trial of 1925?

The Scopes Trial in 1925, or if using its official name, the The State of Tennessee v. John Thomas Scopes, was a legal case in the United States in which a high school teacher was acused of teaching human evolution in a state-funded school. That had been banned by the The Butler Act, enacted by the House of Representatives in Tennessee in the same year. In turn, teachers had to refer to the origin of manking as stated in the Bible.