Final answer:
Researchers distinguish between early members of Genus Homo and members of Genus Australopithecus by looking at key anatomical differences and specific criteria such as brain size and tool-making ability.
Step-by-step explanation:
Researchers distinguish between early members of Genus Homo and members of Genus Australopithecus by looking at key anatomical differences and specific criteria. Some of the key anatomical differences between Australopithecus and early Homo species include a larger brain size, changes in bone structure that allowed for better tool manipulation, and a less prognathic jaw. Specific criteria used to define a species belonging to the genus Homo include brain size, tool-making ability, and bipedalism. However, it's important to note that these criteria have limitations, particularly when dealing with fossil evidence.