Complex sentence: The approach to ethnology current at the time of the Society's founding relied on climate and social factors to explain human diversity; the debate was still framed by Noah's Flood, and the corresponding monogenism of human origins.
Split into simpler sentences: The approach to ethnology current at the time of the Society's founding relied on climate and social factors to explain human diversity. The debate of the time was still framed by Noah's Flood, and the corresponding monogenism of human origins.