Complex sentence: "Bradytely" is rarely used in the modern literature but the characteristic of a bradytelic group is that changes fluctuate on a small scale and do not accumulate over time and the term most often used for that evolutionary tempo is "stasis".
Split into simpler sentences: Bradytely, however, is rarely used in the modern scientific literature but the characteristic of a bradytelic group is that its changes fluctuate on a small scale and do not accumulate over time. In the modern literature, the term most often used for that distinctive evolutionary tempo is "stasis".