Complex sentence: By far the most prominent person amongst those who helped the Society evolve was Dr. Bob Brown, who became the director of The Wilderness Society in 1978, and with him the group greatly increased their influence on Tasmanian politics.
Split into simpler sentences: By far the most prominent person amongst those who helped the Society evolve was Dr. Bob Brown, who became the director of the Wilderness Society in 1978. With him, the group greatly increased their influence on Tasmanian politics.