Final answer:
The discovery of a mostly complete cranium in Daka, Ethiopia, is significant as it adds to our knowledge of human evolution, particularly regarding Australopithecus species, contributing to the overall understanding of our ancestral lineage.
Step-by-step explanation:
The mostly complete cranium discovered in Daka is important because it contributes to our understanding of early human evolution, specifically regarding the species Australopithecus. Finds such as the cranium from Daka, along with others like the Taung child and Lucy (Australopithecus afarensis), Paranthropus aethiopicus, and Australopithecus sediba, offer invaluable insights into the morphology, behavior, and progression of hominin species. The cranium from Daka helps archaeologists and paleoanthropologists piece together the physical and developmental traits of these ancestors, helping us understand the evolutionary timeline leading up to modern humans.