Final answer:
The three species in the genus Homo are Homo habilis, Homo rudolfensis, and Homo ergaster, and they lived between 2.5 million to 1.4 million years ago.
Step-by-step explanation:
The three species in the genus Homo are Homo habilis, Homo rudolfensis, and Homo ergaster. Homo habilis lived from about 2.5 to 1.4 million years ago in East Africa and was probably ancestral to Homo erectus. Homo rudolfensis is known only from a few fossil fragments and lived around 1.9 million years ago, possibly in the same region as Homo habilis. Homo ergaster lived around 1.8 million years ago and was the first hominid to have an essentially modern form.