Final answer:
Ancestors of Great Apes like Australopithecus exhibited characteristics more similar to the great apes than modern humans, including exaggerated sexual dimorphism and bipedalism.
Step-by-step explanation:
Great Apes, including ancestors and contemporary species, share physical and behavioral characteristics. These primates have large sizes ranging from pygmy chimpanzees to gorillas. In all species, males are larger and stronger than females. They also have similar brain sizes relative to body mass and exhibit sexual dimorphism.
The ancestors of Great Apes, like Australopithecus, shared more similarities with the great apes than with modern humans. They exhibited exaggerated sexual dimorphism, with males being much larger than females, similar to gorillas and orangutans. They also had smaller brain sizes compared to modern humans, but common to great apes. Australopithecus was bipedal, like modern humans, but likely spent time in trees as well.
The Great Apes family, Hominidae, includes four living genera: chimpanzees, gorillas, orangutans, and humans. They share more than 97% of their DNA. All organisms in this family can develop language and culture. Humans diverged from a common ancestor with chimpanzees about six million years ago and have evolved marker features such as bipedalism, increased brain size, and a fully opposable thumb.