Although Presbyterian congregations may seem at first to function independently, each one exists as part of a wider network of congregations within which it is able to develop its own special character. However, congregations have a responsibility to care and pray for other congregations and their leaders share the responsibility of making decisions for the whole Church. The minister (teaching elder) and one ruling elder from each congregation in a particular region meet together as a Presbytery. Each Presbytery serves to oversee the activities of each local Congregation in a way that enables the Parish to carry out its unique ministry in their own locality, while ensuring that their ethos retains the distinctives of the Presbyterian expression of Christianity. It falls to the Presbytery to carry out pastoral oversight of the Presbyterian ministers serving within its bounds. In addition, each Presbytery considers and, where appropriate, approves or disapproves any changes to our rules which the State Assembly may desire to make. As of August 2015 the two existing Presbyteries, the Presbytery of Torrens and the Presbytery of Penola were amalgamated to form the Presbytery of South Australia. All Presbyterian Churches in South Australia are part of the Presbytery of South Australia.