Final answer:
ER-1470 has a distinct brain size and skull shape among Homo species fossils, reflecting evolutionary trends like increased brain size and changing dietary habits.
Step-by-step explanation:
The fossil skull known as ER-1470 has a different brain size and skull shape than other Homo species fossils. The fossil record indicates that there has been a progressive increase in brain size in our early ancestors, influencing factors such as dietary habits, like the increased meat eating found in Homo ergaster. Specifically, Homo erectus, which is closely related in the human evolutionary timeline, exhibits features such as a sagittal keel, a nuchal crest, and robust brow ridges. These characteristics contrast with the skulls of other Homo species, which show a reduction in features like prognathism and development toward attributes found in modern humans, such as smaller jaws and teeth, higher brain capacities, and subtle changes in skull shape.