Survivor: “Out of Africa” edition

Last night, I watched a National Geographic special on how some Homo erectus group may have developed into Homo sapiens somewhere in Africa (“Ultimate Survivor: Mystery of Us.” Check regional NatGeo channel sites for program listings). The show presented compelling evidence to support the idea that modern man started to evolve and develop as a distinct species in that continent.

Now, imagine this scenario: a coastline cave-dwelling Homo erectus group in Africa learning how to gather food from the sea. With a rich source of omega-fatty-acid-laced protein that is the ultimate brain food, and without expending much energy in hunts for wild game that were also hominin predators, they now had time for other pursuits. They started organizing their cave dwellings, made tools that were way more refined than necessary, and created shell trinkets which they painted with ochre.

Sounds familiar? They might as well have gathered for tribal council and voted off the weakest link in their evolution group. The shell trinkets would have done well as an immunity symbol, don’t you think? But, I digress.

The ramifications of their other pursuits, which were far removed from mere survival activities, were enormously important. These were huge steps in the evolutionary ladder of Homo sapiens. These were the seeds of culture. If the scientists' deduction holds ground, these would indeed make them forerunners of modern man.

According to the NatGeo feature, Homo sapiens coexisted and may have competed with other hominins, like the Neanderthal Man, Java Man and the recently discovered Homo floresiensis (Hobbit Man). The skills in creativity and ingenuity that Homo sapiens developed could have handily won them the competition. But there’s a twist in the story, as any Survivor episode has. The extremely low genetic diversity among modern man today suggests that we barely made the final cut.

The cause: a natural catastrophic event most likely occurred (see “Toba Volcano: Through the Bottleneck”) that brought the hominins to the brink of extinction. Homo sapiens nearly did not make it as well. In the evolutionary record of modern man, this estimated 10,000 year period brought about by the catastrophic effects of a super-volcanic eruption saw the population dwindle to only less than 3,000. This genetic bottleneck, as evidenced by the extraordinarily low levels of genetic variation within and between races among us, supports an extremely recent origin for Homo sapiens. We must definitely have come from the less than 3,000 who survived.

This also bolsters the “Out of Africa” theory and as the “Toba Volcano: Through the Bottleneck” study phrases it, “puts yet another (the last?) nail in the multiregional coffin.” “Multiregional evolution requires the existence of large populations for long periods, with isolation being rare or absent so that global species could evolve in a single direction. Palaeoanthropological and genetic studies have already done much to discredit this model.” And with the recent discovery of the Flores Island Hobbit Man, “Not only did Homo floresiensis evolve in the absence of gene exchange with other hominins, but no one can argue that LB1 (the first Homo floresiensis skeleton found) contributed to our own species' genetic make-up.”

So, when the catastrophic effects of the Toba event subsided some 63,000 years ago, the bottleneck was released and the surviving hominin population adapted and began to recover. Homo sapiens continued to coexist and most likely competed with Homo neanderthalensis until the Neanderthal Man’s extinction some 30,000 years ago; with Homo erectus javaensis until the Java Man bowed out 25-30,000 years ago; and with Homo floresiensis until the Hobbit Man likewise exited only as recent as 12-18,000 years ago.

And what was our edge over the other hominins? Yes, it was partly due to our more developed brain. But, it was largely because we employed our acquired smarts. Our advantage was our creativity to adapt and our ingenuity to survive. Our learned cultural skills were what made us the ultimate survivor. Mark Burnett can attest to that! Survivor: “Out of Africa” edition… Outwit, Outplay, Outlast!