Fire may appear unearthly, but out of all the planets, moons, and comets, only on earth does fire burn--Carl Sagan & Ann Druyan,
Shadows of Forgotten Ancestors
Even we modern humans are transfixed by the primeval crackling flames of a good roaring blaze. We delight in nurturing the first ember to quicken and spread, feeding the flames, and tending the hearth; fire seems to be hard-wired into our being, from toddler to grandmother. We're so devotional of it that our passion for fire spills over to both our verbal expressions and entertainment preferences. We will stare entranced at light emitting sources simply because we think they're 'pretty'. Fireworks, laser shows, Aurora displays, even dull TV programs, can hold our interest in large part by appealing to this ancient, human, instinct. We 'burn' with passion, 'blaze' with envy, and 'beam' with pride. Fire has been carefully crafted into our collective psyche by natural selection for as long as language and possibly longer. But there was a time, only a moment ago as measured by the stately clockwork of our elegant universe, when fire was new.
In this series on Human Origins,
Part One,
Part Two, and
Part Three, we've followed several clades of walking apes out of their steamy jungles, onto the forested floors and meadows, and out to the vast African savannas. Starting with the enigmatic early ardipithecus, then the holotype specimen for
A. afarensis known as Lucy, and ending finally on the most successful intelligent hominid to walk the earth; Homo ergaster. Our focus has been on morphological changes in skeletal anatomy of creatures that more or less seem content to stay put, along with the chipped cobbles and flakes they left behind. For over six-million years, most of the hominids we know of were limited to the Dark Continent, used only simple stone tools, and did not as far as we can tell use fire or complex language. One million years ago,
H. ergaster would change all that. From that point on, the driving force behind human evolution manifests itself in cultural advances, leaving only indirect evidence for present day researchers to piece together in the form of artifacts and fossil crania. Fire and fire alone may have made us human, it may have served as an inspirational muse for this intellectual Quantum Leap.
We don't know where or how fire first became our trusted ally. Those events are shrouded forever in the dim mists of prehistory. The oldest preliminary evidence for that association dates to about 750,000 years ago in Africa. Our forefathers probably discovered and harnessed it many times, in many places. But the benefits of using fire were enormous and the practice was highly advantageous. Fire acts as a predigestion regimen for tough plant and animal tissue. It sterilizes food. It provides protection from both the elements and roving bands of toothy Pleistocene horrors. And it kickstarts the human race.
Anyone who's been lost in the wilderness through a single night can tell you; when the sun goes down, it's gets dark! Our earliest ancestors probably had to stop doing whatever they were doing at sunset. Perhaps they sought out trees to build ancestral nests, perhaps they huddled in rocky windbreaks or hollows on the ground. They surely had to be terrified through the long equatorial night, as the hoots and growls of predators all around them penetrated the blackness. Youngsters, snuggling close to adults, as the ghastly luminescent eyes of the great cats or hyenas lit by moonlight drifted in and out of the surrounding scrub, had every reason to fear real monsters: Ancient nightmares, shadows of our ancestors. Implanted so deeply in our lineage they still visit our own children, haunting their dreams and imaginations, as they slumber safe and sound in their modern, artificial caves to this day.
But light a fire in the wilderness and you have instant social nightlife. The ancient circle 'round the campfire congeals with the flames. Around those early, blazing, cultural centers, men, women, and children, are forced into close proximity. Speech, technology, and culture is now on the fastrack. For the first time, a palpable sense of "us", here in the warm glow of our hearth, and "them", the Ice Age megafauna looking in warily from the distance, develops.
In the middle Pleistocene, about one-million years ago, Homo ergaster spreads eastward clear to the shores of Indonesia, assuming a distinct morphology we designate as Homo erectus along the way. H. erectus is sometimes also used to refer to late model Homo ergaster in Africa. It all depends if you're a Lumper or a Splitter. The primary diagnostic morphological differences between early and late ergasters is the increase in cranial capacity, a lessening of the primitive ancestral features such as the brow ridges and sulcus behind the super orbital features, and an occipital torus-a smooth, flattened ridge of bone at the base of the skull where powerful muscles attached from the spine and upper back. Some erectus skulls such as those found in the rich deposits of Zhoukoudian, developed characteristic 'arched' brow ridges, while others stick with the straight single bar over the eye sockets. Erectus/ergaster/bergenesis ranged over a much wider area than earlier hominids, so we would expect much greater regional variation or subspeciation.
Creationist FAQ: In the late 19th century the first H. erectus fossil came to light. Early paleoanthropologists at the time of course did not really understand hominid phylogeny with the degree we now enjoy-thanks in large part to their very work. Known at the time as Java Man, it consisted of a skull cap of a primitive looking crania in the 1000 cc range. Java Man's discoverer, Eugene Dubios, originally found two skulls in the same general area about 100 kilometers apart. One was a modern human specimen, the other was the Java Man skull cap. Dubois, recognizing the anachronistic morphology of the skull cap, speculated that it had belonged to a giant, early, relative of the Gibbon (Technically not too far off by the way). In the 1970's Young Earth Creationist Duane Gish would immortalize this find and confabulate an infamous distortion regarding the Java specimen which is still a standard weapon in the creationist arsenal of dishonesty. The original skull cap, shown below and overlaid onto a reconstructed erectus skull, was definitely we now know, not a Gibbon.
Gish claimed that Dubios had found both skulls at the same place, making them both the same age, but had kept the existence of the modern one a secret so as to sensationalize his discovery of Java Man. Gish furthermore often implied that 'evolutionists' tried to cover up the 'fact' that the Java Man was really nothing more than the skull of an extinct ape closely related to modern Gibbons. Both claims are distortions. And despite being corrected on the facts repeatedly, like all good creationists, Dr Gish kept shoveling this nonsense at lectures and debates until he retired from the lucrative field of fleecing the faithful.
Meanwhile, in Central Africa, incessant warming and cooling throws the climate into a chaotic metastability the world over. Hot, steamy weather, dry spells, cold snaps, and stormy seasons, alternate with unpredictable periods of decades, centuries, or millennia. The Mediterranean Basin empties and refills, over and over, dancing in resonance to glacier driven fluctuations in global sea levels, themselves advancing and retreating from the polar regions repeatedly like a yo-yo. The process leaves behind extraordinarily intricate veneers preserved in the geology of that inland sea. Alternating stratigraphy: A complex, multilayer cake, made up of thin layers of shale, fossils, limestone, and salty evaporates. This dynamic, unforgiving environment selects only the most intelligent and flexible from among the ergasterine stock. The survivors add a respectable 300 CC to their 900 CC braincase over the next two-hundred thousand years. A new hominid arises from erectus/ergaster seven-hundred thousand years ago and moves north into southern Europe: Say hello to Homo heidelbergensis and his Early Mousterian Tool Kit.
H. heidelbergensis, or bergie, may have walked/swam across the Strait of Gilbratar, or right through the shallows and island archipelagos of the Mediterranean Basin during a time of low sea levels, or he may have gone the long way through the middle East-or more likely, all of the above. It was the first sign of an exploratory desire. It is the birth of human wanderlust.
But regardless of which route they used to colonize the north, they would have perished in the face of the moving mountains of ice and harsh climes they encountered without fire. Even armed with both fire and a new expanded brain, our intrepid European settlers are the hardest hit by the fluctuating climate. Over and over they are chased out of the highlands and plains of Europe back into the river valleys and creek bottoms by advancing walls of ice. Their rate of evolution in the crystaline shadows of the moving glacial mountains is furious. What emerges after this ruthless selection is a hominid radically reworked by evolution, quite different from the angular, lean bergensis ancestors which walked into Europe. The new hominid is exquisitely adapted for the cold, muscled like a body builder, with a keen penetrating intellect, and the meaty diet of a modern wolf. By about two-hundred and fifty-thousand years ago, European bergie had become Homo Neandertalensis, or Neandertal Man (Or neanders for short).
Perhaps no other hominid has been so mischaracterized as the Neandertal. They have been the victims of dozens of novels and sappy caveman movies, portrayed as slouching morons struck with arthritis, bereft of simple cognizance. The drooling, brawny, savage. They are routinely presented even today as the archetypical cretin; a subhuman object to be ridiculed, scorned, and eliminated. To be a Neandertal in our parlance means to be a hulking ignoramus, an idiot, an ape.
If what you know about neanders was taken from that pop-culture depiction, little you've been told about these magnificent people is accurate. They were tough as nails, fiercely loyal to their families and clans, and far from being remedial idiots, they were the most technologically adept beings to ever walk the planet in their day, bar none. They may have been capable of building great cities, crossing the oceans, and exploring the reaches of space; we will never know. Sadly, they didn't get the chance.
In the evolutionary dynamo of Africa, far to the south of the neander strongholds nestled in the rustic snowy valleys of southern Europe, a new hominid appears shortly after the emergence of H neandetalensis. He is tall, gracile, gregarious, and brilliant. He is an anatomically modern human being and his kind will sweep over the world stage.
But first our early Homo sapien forebears will have to survive the greatest disaster to befall hominids since the advent of the ice ages. One which lays waste to Africa and Asia, and almost drives our own first family of sapiens into extinction. The few battled hardened survivors who cross the environmental holocaust will come boiling out of Africa like angry ants, replace or eliminate their hominid cousins to the far east and frigid north, and conquer the world. By the time they're done, the planet of the hominids will never be the same. That story next time my fellow sapiens ...