Final answer:
The genus Homo appears in four different species: Homo habilis, Homo erectus, Homo neanderthalensis, and Homo sapiens.
Step-by-step explanation:
The genus Homo appears in four different species, including Homo habilis, Homo erectus, Homo neanderthalensis, and Homo sapiens. Homo habilis, meaning "handy man," had a larger brain compared to australopithecine species and used stone tools. Homo erectus, which first evolved about 1.9 million years ago, had a larger body size and migrated from East Africa to Eurasia. Homo neanderthalensis, commonly known as Neanderthals, were a closely related species to Homo sapiens and existed until about 40,000 years ago. Lastly, Homo sapiens, or modern humans, are the only living species within the genus Homo.