One of the most important debates in current paleoanthropological research concerns the origins of both anatomically modern Homo sapiens and modern human behavior (which includes language and symbolic culture).
In Europe, which has been a principal focus of research since the 19th Century, it now seems clear that the earlier industries of the Middle Paleolithic (what is called Mousterian, and which dates from roughly 250,000 – 35,000 years ago) are associated with a specific kind of hominid, namely Neandertals.
While the taxonomic status of these hominids is still under debate (that is, whether or not they are the same species as us), it has been increasingly clear that the nature of their behavior was not the same as subsequent populations of modern humans who came into the region at about 40,000 years ago.
Thus, in Europe, the abrupt nature of the change in behavior and its association with two different hominid types, suggests that modern behavior is somehow linked to the apparent changes in physical morphology.
While it has been suggested that at least some of this linkage may be genetically based (Klein and Blake 2002), it is equally possible that it is simply an historical link (analogous to European colonization of both the New World and Australia).
More recent archaeological research in South Africa (Henshilwood et al. 2001; Henshilwood and Marean 2003; Klein 2001; McBrearty and Brooks 2000), as well as numerous genetic studies (Forster and Masumura 2005; Klein 2003; Macaulay et al. 2005), suggest that the origins of both anatomically modern hominids and modern behavior (as evidenced by the presence of art, bone tools, and hafted projectile points) originated in Africa at about 120,000 years ago and that these populations subsequently spread to other parts of the Old World and essentially replaced indigenous populations.
The timing of this spread, and the underlying adaptation that allowed such a successful radiation, is a major research question in paleoanthropology.
The European Paleolithic
Neandertals: ca. 250,000-30,000 years ago
Modern Humans: arrived ca. 40,000 years ago
Behavioral Shift: ca. 40,000 years ago
South African Evidence
Modern Humans and Modern Human Behavior: ca. 120,000 years ago
Why, Where, and When did these modern humans spread throughout the Old World?