Stringer and McKie provide an excellent review of the archeological evidence which suggests that the more elaborate tool kit and the enhanced mental abilities possessed by modern humans created a more complex society, which spread widely throughout Europe and exploited a wide range of natural resources and, most important, usurped Neanderthal territory. Unlike Neanderthals who remained in one place year-round, the more sophisticated modern humans roamed over larger areas, collecting various raw materials and exploiting seasonal food sources. Excavation of Neanderthal sites strongly suggests that they did not wander far from their base camps. In short, while Neanderthals possessed many human-like behaviors, such as extended childhood, large brains, fire making, probably burials, the construction of shelters and so on, their minds were limited and the increased complexity of modern human society ultimately drove them into relict areas, such as southern Spain, where they expired about 30,000 years ago.
"African Exodus" reminds us that there are no guarantees in evolution. Neanderthals, after several hundred thousand years as a distinct lineage, ultimately met extinction. The final chapter of this thoughtful book reminds us of our own precarious existence. For example, since the agricultural revolution, humans have become a species out of control, reproducing at frightening rates, becoming more and more susceptible to some of the world's most deadly epidemics and at the same time depleting the Earth's natural resources at an alarming pace. Stringer and McKie warn us that we are no longer in balance with nature. Genetically we are little changed from our hunter-gatherer past, but our technology has taken us to the surface of Mars. Perhaps the imbalance created by the disparity between our biological and technological evolution is the cause of many of humankind's ills. Stringer and McKie warn us that it may be foolhardy to assume that technology will triumph over nature. After all, we are often uncomfortable with technology; witness the numbers of us intimidated by the prospect of programming the family VCR.
The authors write, "We triumphed in the end for a variety of reasons: social, cognitive, behavioral and technological." Where do we go from here as a species? We are survivors; we are the lone existing branch on the human family tree; we deserve to be here just like any other species, but we have the frightening obligation of being in charge. While "African Exodus" holds no secrets for our future tenure on earth, it stimulates us all to ponder our humanity.