By Seneca III
Part II – Origins (part 1 is here)
Four and a half million years ago in the first few seconds of the early morning of our species the earth moved. Slowly but inexorably Africa subtended Asia, and Africa broke.
Africa, then, was an expanse of low, rolling, tree-clad hills stretching from the Atlantic to the Indian Ocean, from the Inland Sea to the frigid southern waters. It was a quiet place; a comfortable, undemanding habitat where evolution appeared to have stalled and a relatively stable ecological balance had triumphed such that the daily demands of survival lacked the innate ferocity of the preceding Lower Tertiary period.
But this Africa would be no longer. The confrontation between one tectonic plate and another initiated an event that changed a small, rocky planet orbiting a minor star on the outer arm of an inconsequential galaxy – and it changed it forever. In a few short moments of geological time the shuddering continent heaved and buckled, its convulsions raising to the north a range of mountainous catchments that would feed into a great river basin in its centre and at the same time curtail the extent of the precipitation that had once fallen evenly across the land. Their north facing flanks and the hinterland beyond became a place of rain shadow, a dry, hot desert stretching to the shores of the Mediterranean.
Simultaneously, from the Northeast, there opened a deep wound in the earth’s crust as the mantle split and the ocean thundered into the fiery depths where magma turned the waters of a nascent Red Sea into superheated steam.
Southward, on land, beyond the boiling waters, a serpentine chasm speared into the heart of Eden reaching almost to the tip of the continent, slicing through the blanket of forest and coming close to cutting the eastern seaboard free from the rest of the land mass. Here molten lava welled up, bubbled and hissed, rose and roiled until finally settling to the bottom of the fracture, slowly solidifying, and with this cooling came a chain of undulations and cracks in the surface, embryonic lakes awaiting the fulfilment of their promise as they lay strung between sheer cliffs of basalt in the west and a vast wedge of land to the east.
This wedge of land, this protuberance, was the key player in the environmental and evolutionary drama that was about to unfold, for that part of the Africa plate upon which it sat was now semi-detached and had tilted along its north-south axis, pushing high up into the path of the easterly monsoon. Driven by the wind and Coriolis force the water-heavy clouds followed the rising slope into the cold upper air beyond the scarp and deposited the bulk of their contents into the open wound beyond, filling the lakebeds and greening the plain that surrounded them.
Soon vast herds of herbivores and their attendant predators would roam here, later to be joined by an arboreal omnivore that would adapt to the demands of life in the open in a strange and unique way.
Thus came into being the womb and cradle of mankind, the Great Rift Valley, where one day an anthropoid ape would lift its knuckles out of the red African earth and walk upright.
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We are all out of Africa, and what a fascinating, wonderful journey it has been. It did not happen all at once of course, but to the best of our knowledge over a period from 200,000 to 15,000 years ago. Nor was it a single, linear exodus. There is evidence that shows there was more than one wave, perhaps several, each having a particular geographic and temporal dynamic, and at one stage our numbers became so small we came close to dying out altogether.
The fossil record, incomplete though it is, is only one part of the jigsaw. In recent decades the use of DNA analysis has enabled quite accurate delineation of the time lines and extent of our human Diaspora. For ease of explanation these can be compartmentalised into six phases. Briefly:
Into Africa.
There is a consensus between paleoanthropologists and geneticists that modern humans arose in the Rift Valley close to 200,000 years ago and a fossil found in Omo Kibish, Ethiopia, does substantiate this hypothesis. (Sites in Israel hold the earliest evidence of modern humans outside of Africa, but that group went no further, dying out about 90,000 years ago.) In Africa fossil remains at a site at Klasies River Mouth in modern day Cape Province date from 120,000 years ago.
Out of Africa.
Genetic data show that a small group of modern humans left Africa for good 70, 000 to 50,000 years ago, settling first in the the Arabian Peninsula and eventually replacing all earlier types such as Homo Neanderthalensis. All non-Africans are the descendents of these travellers who may have migrated around the top of the red Sea or across its narrow southern opening.
The First Australians.
Discoveries at two ancient sites – artefacts from Malukunanja and fossils from Lake Mungo – indicate that modern humans followed a coastal route along southern Asia and reached Australia nearly 50,000 years ago. Their descendents, Australian Aborigines, remained genetically isolated on that island continent until recently.
Early Europeans.
Paleoanthropologists long thought that the peopling of Europe followed a route from North Africa through the Levant. But genetic data show that the DNA of today’s western Eurasians resembles that of people in India. It appears possible that an inland migration from India seeded Europe between 40.000 and 30,000 years ago.
Expansion into Asia.
Around 40,000 years ago humans pushed into Central Asia and arrived on the grassy steppes north of the Himalaya. At the same time they travelled to Southeast Asia and China,eventually reaching Japan and Siberia. Genetic clues indicate that humans in northern Asia eventually migrated to the Americas.
Through the Americas to Cape Horn.
Exactly when the first people arrived in the Americas and the exact sequence of their dispersion or re-dispersion is still hotly debated. Genetic evidence suggests it was between 20,000 and 15,000 years ago when sea levels were low and a land bridge connected Siberia to Alaska. Ice sheets would have covered the interior of north America, forcing the new arrivals to travel down the west coast, leaving artefacts and fossils at Kennewick (9,500 Before Present Era), Spirit Cave (9,500 – 9,400 BPE), Clovis (13,500 BPE) in the north before reaching Monte Verde in Southern Chile 15,000 to 12,000 years ago.
The wonder is that we survived at all yet survive we did and in the process of our migrations we have adapted to and colonised every biome on the planet where an air breathing species can exist. From arctic wastes to lush tropics, from vast plains to high mountain pastures, from cool, damp woodlands to sere desert we have set down our feet and in turn these environments have, particularly in extremis, shaped the way we think and act and go about the daily business of life.
With this in mind I shall, in a later essay, turn some attention to the remnants of the second phase, those who did not move onward and outward but remained in and colonised the Arabian Peninsula and its immediate environs. Here a harsh climate and demanding terrain forever shaped the minds and defined the way of life of a certain subset of our species – the Semitic peoples.
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In the years prior to the advent of DNA analysis much was made of the fact that there were ‘missing links’ in the fossil record. True, there were, and they remain so to this day, but we couldn’t dig up the whole planet in the hope of finding something that may have conveniently died where the geoclimatic conditions were favourable to fossilisation. DNA analysis has now filled in most of the gaps but in a sense there do remain missing links, not fossils but events that even DNA cannot answer – why did our distant ancestors come down from the safety of the trees and venture out into the dangerous open spaces beyond and, having done so, what drove them to adopt bipedalism?
There are no definitive answers to either question, only speculation, and that is a fertile field indeed. Some biologists propose that when the primate family tree branched to separate the apes from the monkeys the former lost the ability to digest unripe fruit, which monkeys could harvest before the apes and so forcing the latter to seek other food sources. Others, behavioural anthropologists, may argue that it was simply a case of a species taking advantage of a new niche. Perhaps it was a combination of both and of other factors such as major changes in the forest habitat brought about by the climactic events that had created the Great Rift Valley. Whatever it was we will probably never fully understand.
The matter of apes adopting bipedalism (another seminal branching of the primate family tree) is one that offers a much richer seam of hypotheses for us to mine. Physiological and behavioural studies of modern apes have revealed some interesting clues, principally that apes are not true quadrupeds in the same sense as say an antelope or a lion or a meercat. Their long forelimbs evolved for climbing and swinging and as a consequence when walking on four limbs apes have to ‘’knuckle walk’, an ungainly and not particularly efficient gait that locates their shoulders much higher than their pelvis and thus positioning them already part way to an upright stance.
Furthermore it is not unreasonable to assume that a habit of rising briefly upright in order to scan above the long grass of the plains for approaching predators was a necessary defensive mechanism. Thence over thousands, perhaps hundreds of thousands of years those whose pelvic girdles had or had developed minor muscular and skeletal changes that enabled them to stand frequently and for longer would stand a better chance of survival and consequently have a better chance of passing on these small but accumulative mutations to future generations.
However it happened this permanent freeing of two limbs from a locomotive function, limbs with an opposed thumb at their extremities, opened another evolutionary door which eventually lead to the crafting of tools and weapons, by which means these proto-humans came to manipulate their environment in ever more sophisticated ways.
In due course, possibly out of an intuitive need to cooperate effectively, there followed the development of language and an increase in brain capacity, although which came first is uncertain. What is certain is that their descendents, modern man, would arise slowly but inexorably through a long chain of distant relatives, Australopithecus, Homo habilis and many others, to become what we see when we look in the mirror today, Homo sapiens sapiens.
I said earlier that speculation on these matters is a fertile field. Well I too speculate, and as I have a tendency to anthropomorphise, sometimes mischievously, here, for what it’s worth, is my contribution to the academic debate:
[One day long after the Rift had settled into the steady rhythms a functional biome Mrs. Ugg came swinging through the trees, a child clutching tightly to her chest hair and several other older children following in her wake. She settled on a branch next to Mr. Ugg and eyed him malevolently for a few moments before speaking.
“Look at you, you great lump” she said “all you do all day is sit there on that branch sucking on the last of the ripe mangoes and watching those monkeys down there kicking a coconut from one end of a field to the other. And look at them! What on earth are they up to falling over and screaming ‘Referee!’ every time another one runs past them? You’re all bloody daft and I’ll tell you this, the kids are hungry and unless you get off your fat, idle butt and get out there and find us some food you can give up all hope of ever again getting your hands on my butt, or anything else for that matter. So there!”
And so it came to pass that the exodus began. Ugg led his people into the new world, Mrs. Ugg relented and was again fruitful and the tribe of Ugg grew and spread over the land and prospered until…
…several Millennia later one of their descendents was out with his troop, foraging on the savannah. It was back aching work bending over all day, bums in the air, scratching for edible roots and insects. Suddenly, impulsively, Ugg The Latest stood upright, placed the heels of his hands on his back and pressed them one on each side of his aching spine. Ahh! he murmured, as he stretched and sighed in relief. Then he looked around at the panorama before him and froze in amazement.
“Good God!” he said to himself, “look at all that Totty, I’m going to have to do this more often.” and then, after a short period of pleasant contemplation “Oh, hell, now I suppose I’m going to have to learn to count as well!”
And so it came to pass that Ugg began to spend a lot of his time in an upright stance, a stance soon adopted by all the male members of his tribe and then in quick order by the female members, but for an entirely different reason. Or so it is writ in the Book of Seneca III.]
In closing I submit that in the sublime moment of an ancient ape’s epiphany was born the eternal trichotomy – Belief, Recreational Sex and Reasoning – and as the three have been uneasy bedfellows ever since, particularly within the Islamic mind-set, I feel they are worth examination in detail. How you? Do tell.
Seneca III
May 27th, 2011 CE
