I think the 40,000 years ago figure as a time of some significant change is defunct in current paleo-anthropology. 30 or 40 years ago, the 40,000 figure was used when it was said that "modern man" emerged in Europe and there were fossils (Cro-Magnon) in Europe alone from 40,000 ago. Now the emergence of homo sapiens from the missing link species is more definitely placed in Africa , and at 200,000 years earlier by mainstream (European )anthropology. In other words , the Cro-magnon of 40,000 years ago are no longer considered the first homo sapiens.
Charles
^^^^^^
Homo sapiens H. sapiens ("sapiens" means wise or intelligent ) has lived from about 250,000 years ago to the present. Between 400,000 years ago and the second interglacial period in the Middle Pleistocene, around 250,000 years ago, the trend in cranial expansion and the elaboration of stone tool technologies developed, providing evidence for a transition from H. erectus to H. sapiens. The direct evidence suggests there was a migration of H. erectus out of Africa, then a further speciation of H. sapiens from H. erectus in Africa (there is little evidence that this speciation occurred elsewhere). Then a subsequent migration within and out of Africa eventually replaced the earlier dispersed H. erectus. This migration and origin theory is usually referred to as the single-origin theory. However, the current evidence does not preclude multiregional speciation, either. This is a hotly debated area in paleoanthropology.
Current research establishes that human beings are highly genetically homogenous, meaning that the DNA of individual Homo sapiens is more alike than usual for most species, a result of their relatively recent evolution. Distinctive genetic characteristics have arisen, however, primarily as the result of small groups of people moving into new environmental circumstances. Such small groups are initially highly inbred, allowing the relatively rapid transmission of traits favorable to the new environment. These adapted traits are a very small component of the Homo sapiens genome and include such outward "racial" characteristics as skin color and nose form in addition to internal characteristics such as the ability to breathe more efficiently in high altitudes. H. sapiens idaltu , from Ethiopia, lived from about 160,000 years ago (proposed subspecies). It is the oldest known anatomically modern human.
http://en.wikipedia.org/wiki/Human_evolution