Final answer:
Homo erectus and H. habilis differ in terms of brain size and physical appearance.
Step-by-step explanation:
Homo erectus and H. habilis are two different species belonging to the Homo genus. One key difference between them is their brain size. H. erectus had a larger brain, ranging from 775 to 1,100 cubic centimeters, compared to H. habilis, with a brain size of 600 to 750 cubic centimeters. Another difference is their physical appearance, with H. erectus being taller, with longer legs, and having a nose with downward-facing nostrils.