The Koobi Fora Research Project attempts to answer a broad range of key questions regarding the emergence of hominids in East Africa. Several critical to our evolutionary story relate to the circumstances of the origin of our own genus Homo and the spread of Homo erectus into northern latitudes:
Why did Homo appear?
Studies of past faunal assemblages have suggested that 2.5 million years ago there was a major turnover of fauna, when many species became extinct and many new taxa evolved. This has been linked to a major change in climate, and the origin of the genus Homo. More recently studies have indicated a more obvious turnover of fauna and changes in habitat 1.8 million years ago, the time when Homo erectus first appears outside Africa? Additional studies are required to investigate these questions and the sequence and effect of climatic changes that took place at these time intervals.
When did Homo appear?
The earliest generally accepted evidence for Homo is a fragmentary maxilla from Hadar dated at 2.33 million years. More complete specimens from the Turkana basin dated between 1.8 and 2.1 million years, although generally accepted as Homo have led to more questions than answers. In order to clarify the affiliations of these species more specimens are required.
What was the earliest species of Homo?
Relatively complete skulls and skeletal elements from Olduvai Gorge and from the Turkana Basin have been named as species of Homo but so far the evidence is insufficient to show which is the ancestral species, and how these species are related. Controversy and uncertainties continue as to the correct taxonomic affiliations of these species.
What species gave rise to Homo erectus?
Resolution of the above question will also clarify the origin of Homo erectus. Did Homo erectus evolve from one of these recognized species or did it migrate into east Africa from elsewhere? Additional good fossil specimens are the only way that these questions can be answered.
What led Homo erectus to migrate out of Africa?
Homo erectus was the first human ancestor to move out of Africa into the colder northern climates. The earliest evidence for Homo erectus in Africa is from the Turkana Basin and is dated just over 1.8 million years ago. This is almost contemporaneous with the earliest evidence of Homo erectus outside Africa, at Dminisi. New dates on specimens from Java also suggest that Homo erectus arrived in Asia close to this time. What prompted the movement of Homo erectus out of Africa 1.8 million years ago?