Homo (from Latin homō 'man') is the genus that emerged in the (otherwise extinct) genus Australopithecus that encompasses the extant species Homo sapiens (modern humans), plus several extinct species classified as either ancestral to or closely related to modern humans (depending on the species), most notably Homo erectus and Homo neanderthalensis. The genus emerged with the appearance of Homo habilis just over 2 million years ago. Homo, together with the genus Paranthropus, is probably sister to Australopithecus africanus, which itself had previously split from the lineage of Pan, the chimpanzees.

Homo erectus appeared about 2 million years ago and, in several early migrations, spread throughout Africa (where it is dubbed Homo ergaster) and Eurasia. It was likely the first human species to live in a hunter-gatherer society and to control fire. An adaptive and successful species, Homo erectus persisted for more than a million years and gradually diverged into new species by around 500,000 years ago.

Homo sapiens (anatomically modern humans) emerged close to 300,000 to 200,000 years ago, most likely in Africa, and Homo neanderthalensis emerged at around the same time in Europe and Western Asia. H. sapiens dispersed from Africa in several waves, from possibly as early as 250,000 years ago, and certainly by 130,000 years ago, the so-called Southern Dispersal beginning about 70–50,000 years ago leading to the lasting colonisation of Eurasia and Oceania by 50,000 years ago. Both in Africa and Eurasia, H. sapiens met with and interbred with archaic humans. Separate archaic (non-sapiens) human species are thought to have survived until around 40,000 years ago (Neanderthal extinction), with possible late survival of hybrid species as late as 12,000 years ago (Red Deer Cave people).

 

Note:   The above text is excerpted from the Wikipedia article Homo, which has been released under the GNU Free Documentation License.