Our understanding of the chronology of human evolution is changing almost monthly as archaeologists, physical anthropologists, primatologists, geneticists, and other scientists make new discoveries.  For that reason all dates here are subject to question.  The general outlines of the debate are relatively stable. 

Here is a good web site for more information: http://www.becominghuman.org/

Homo Erectus to Homo Sapiens:

• Transition began to take place 250-400,000 years ago with the emergence archaic homo sapiens (fossilized Homo sapiens skulls dating 160,00 B.P. found in Ethiopia in 1997.
• Principal archaic human species to live in Europe is called Homo neandertalenis.
• What about Neanderthals (Homo neanderthalenis)?  Are they archaic Homo sapiens who lived in Europe or are they a regional evolution of Homo erectus?  DNA evidence seems to suggest the later.  

Two theories:

• Homo sapiens evolved gradually and in parallel lines from widely dispersed homo erectus populations of Africa and Eurasia.  (the Regional Continuity Model).
• Homo sapiens evolved from Homo erectus in Africa and migrated to Eurasia gradually replacing resident Homo erectus populations.  This is supported by the narrow divergence in our DNA that suggest that regional variations in Homo sapiens are relatively recent and date to about 250,000 B.P. (the Replacement Model).

Homo sapiens sapiens (us):

• Earliest modern human fossil remains were found in Omo in East Africa buried with advanced tools (bola or throwing stick, flake tools, flake blade).  They date to 130,000 years ago.
• Homo sapiens sapiens moves to Europe at about 40,000 years before present at the latest and gradually replaces Neanderthals, who had been in Europe for about 230,000 years.  

Climate of Europe during this period had several warm-cool cycles, which would have favored a highly adaptable species with advanced communication and problem-solving capabilities:

• 130,000 to 110,000 years ago it was like today

• 110,000 to 75,000 years ago it was slightly cooler 

• 75,000 to 30,000 years ago it was cool to borderline glacial

• 35,000 to 12,000 years ago was a full glacial climate (this is the period when the archaeological evidence shows Homo sapiens sapiens replacing Homo neaderthalenis in Europe)

The glacial climate ended abruptly 12,000 years ago (beginning of the Mesolithic period). The last 12,000 years have seen smaller fluctuations in climate, most lasting a few hundred to a few thousand years, but none returning to the glacial climate of 20,000 years ago.

During most of the glacial period, the Neanderthals were the only human inhabitants of Europe. Fully modern people arrived about 40,000 years ago and within 5,000 years after that the Neanderthals were gone. 

The modern humans of the Upper Paleolithic produced functional and beautifully-flaked blades, punches, burins, needles, wooden and bone tools (the first known) and leather goods. Many of these had designs carved on them (also the first known), indicating a level of artistic expression that is not seen with the Neanderthals (though a suspected bone flute has been found in a Neanderthal site).

Notes compiles by Mary Prevo, Hampden-Sydney College, May 21, 2002. January 12, 2010.