Overberg Geoscientists Group
200 000 yrs ago
Modern Humans
Anatomically modern humans – Homo sapiens – evolved from predecessor Homo species that had developed from pre-existing Australopithecines. The exact lineage is not known, but the basics are there.
All evolution, not just Hominids, incorporates developmental changes, not one step followed by another. It was, and is, a progressive change, and, as such, it may be very difficult to define individual species that changed slowly over time. This has led to a lot of potentially differing species within the Homo genus.
These are often very dubious in their anthropological placement and can be considered to be merely variations in the main species lines. This may be due to anthropologists working with insufficient fossil evidence, or merely that they wish to subdivide the species even further.
​The first clear ancestor species, that has been ascribed to the genus Homo was Homo habilis. “Handy man”. For the first time stone tools were made and used.
The next widely recognized Homo species was Homo erectus.
H. erectus (the African variant is sometimes called H. ergaster) evolved 2 million years ago and was the first archaic human species to leave Africa and disperse across Eurasia.[22] H. erectus also was the first to evolve a characteristically human body plan.
Homo sapiens emerged in Africa around 200,000 years ago from the descendants of H. erectus that remained in Africa. H. sapiens migrated out of the continent, gradually replacing or interbreeding with local populations of archaic humans. Humans began exhibiting behavioral modernity about 160,000–70,000 years ago,[27] and possibly earlier.
The "out of Africa" migration took place in at least two waves, the first around 130,000 to 100,000 years ago, the second (Southern Dispersal) around 70,000 to 50,000 years ago. H. sapiens proceeded to colonize all the continents and larger islands, arriving in Eurasia 125,000 years ago, Australia around 65,000 years ago, the Americas around 15,000 years ago.
Human evolution was not a simple linear or branched progression but involved interbreeding between related species. Genomic research has shown that hybridization between substantially diverged lineages was common in human evolution. DNA evidence suggests that several genes of Neanderthal origin are present among all non sub-Saharan African populations, and Neanderthals and other hominins, such as Denisovans, may have contributed up to 6% of their genome to present-day non sub-Saharan African humans.
Further reading:
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Spamer EE (1999). "Know Thyself: Responsible Science and the Lectotype of Homo sapiens Linnaeus, 1758". Proceedings of the Academy of Natural Sciences of Philadelphia. 149
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Dunsworth HM (September 2010). "Origin of the Genus Homo". Evolution: Education and Outreach. 3 (3): 353–366.
Johanson D (May 2001). "Origins of Modern Humans: Multiregional or Out of Africa?". actionbioscience. Washington, DC: American Institute of Biological Sciences.