Introduction
The following is merely one layperson’s opinion and speculations on the conditions and processes that produced the first tool making, sentient, intelligent creatures that we call human. It addresses the period during the forest-savanna transition in East Africa and through to the first handaxe and spear making, a period of roughly three and a half million years (5-1.5 million years BCE). The author will propose some probable events that must have occurred in this period.
It is not generally recognized by the public that our pre-human ancestors went from among the weakest, most defenseless prey on the East African savanna to the predatory terror of the world, all in an interval of perhaps a million years. What happened? How did we do it? We were surrounded by vicious predators. We had no claws, no fangs. We couldn’t dig, and there was not much to climb in that place and time. We were much smaller than we are today. We adopted a fragile, two-legged stance in a four-legged world. Clearly, we were not built for fighting, and we were inferior at running. So, how could this be?
Happily, much research has been done and far more is known about this than has been conveyed to the general public. The results are in the archaeology, paleontology, and paleoanthropology literature. It is available to anyone who cares to make the effort to read and understand. A very readable summary of the research findings is given by Stringer and Andrews1. We shall take several key ideas from Harris2. Although we shall rely heavily upon these two references, the particular interpretations and opinions, here, shall be due solely to the present author. I challenge the reader with the following question: "Do we really believe in natural selection, or not?"
Changing Climate
To begin, perhaps ten million years ago East Africa was heavily forested and well populated with tree-dwelling primates of a variety of types. Around five million years ago (at the end of the Miocene Epoch), the climate began to change from wet subtropical to much more arid, grassland conditions. Over about the next three million years, the heavy forest cover gradually died out, and it is in the late stages of this transition period that things become interesting. Our primate ancestors were forced down onto the ground, amidst the most brutal lineup of predators in the world. Lion, leopard, hyena, wild dogs, many in large packs. They are all still there today, just as they were. You may see them on almost any African wildlife show on television, literally ripping prey limb from limb. To get the picture that our ancestors faced, imagine yourself set out at night on the African plain among these predators.
An important set of facts to keep in mind while reading the following is this: Archaeological and paleontological research and field work have shown that bipedal primates first appeared in East Africa approximately five million years ago, roughly at the beginning of the transition from forest to savanna conditions. These creatures would face a difficult transition to savanna living. Some of the other animals would have difficulties, others not. The lions and leopards of the time had forest-dwelling predecessors who, being top predators, had no trouble transitioning to savanna living without having to modify their general body conformation and behaviors. Not so for the hyenas and wild dogs. Inasmuch as small, ground-dwelling predators in the present-day equatorial forest do not run in packs, we surmise that hyenas and wild dogs had to make many adjustments for grassland living. During the wet-arid transition, they might not have been a threat to our pre-humans, but as their pack behavior evolved, they would become a dire threat. We speculate that the cheetah was originally much smaller and more gracile. More on this, later.
Pre-Human Primates
So what would have our direct, pre-human ancestor looked like, at the point where the tree cover began to disappear? Let us begin our hypothesis. It couldn’t have been a ground-dwelling ape. With the tree cover gone, they would have been too slow and clumsy to survive the predation of the big cats. Instead, we hypothesize a smaller, more alert, active and agile primate that looked something like a rhesus or capuchin monkey. Indeed, the first proto-human creatures (Australopithecus) were under five feet tall and had slender, thin-boned body types. On the ground among predators, such a creature would have flight as its sole defense.
The following bit came from the Sigma Xi American Scientist journal sometime in the early 1970s. In East Africa, paleontologists had excavated a sinkhole-like depression that they thought might have been a cave wherein early humans might have lived. Instead, they found large amounts of detritus that had fallen down from above, and scattered among this they found numerous pre-human skulls with few accompanying skeletal bones. They puzzled over this odd fact for some time, until they noticed that many of the skulls had teeth marks on them. After reviewing leopard behavior, it became clear what had happened. Late in the wet-arid transition period, only widely-scattered, small clumps of trees remained, those in low places in the terrain, such as around sinkholes. Leopards carry their prey up into a tree to eat, because otherwise the other predators would move in and eat not only the prey, but the leopard, also. With small prey, leopards consume everything, but the skull is slippery and difficult to hold onto. They tend to accidentally drop some of the skulls, thus their appearance in the sinkhole. Sure enough, when the paleontologists excavated other sinkholes in the region, they found the same thing. It is clear that we were once defenseless prey.
When our primate ancestors were first dropped into this sea of snarling teeth and fangs, they weren’t completely bereft of any useful survival tools. Their tree-dwelling lifestyle equipped them with certain physiological characteristics that were useful then, and still are today in our technological world. First, they had excellent binocular vision because they had to precisely gauge how far away
The following is merely one layperson’s opinion and speculations on the conditions and processes that produced the first tool making, sentient, intelligent creatures that we call human. It addresses the period during the forest-savanna transition in East Africa and through to the first handaxe and spear making, a period of roughly three and a half million years (5-1.5 million years BCE). The author will propose some probable events that must have occurred in this period.
It is not generally recognized by the public that our pre-human ancestors went from among the weakest, most defenseless prey on the East African savanna to the predatory terror of the world, all in an interval of perhaps a million years. What happened? How did we do it? We were surrounded by vicious predators. We had no claws, no fangs. We couldn’t dig, and there was not much to climb in that place and time. We were much smaller than we are today. We adopted a fragile, two-legged stance in a four-legged world. Clearly, we were not built for fighting, and we were inferior at running. So, how could this be?
Happily, much research has been done and far more is known about this than has been conveyed to the general public. The results are in the archaeology, paleontology, and paleoanthropology literature. It is available to anyone who cares to make the effort to read and understand. A very readable summary of the research findings is given by Stringer and Andrews1. We shall take several key ideas from Harris2. Although we shall rely heavily upon these two references, the particular interpretations and opinions, here, shall be due solely to the present author. I challenge the reader with the following question: "Do we really believe in natural selection, or not?"
Changing Climate
To begin, perhaps ten million years ago East Africa was heavily forested and well populated with tree-dwelling primates of a variety of types. Around five million years ago (at the end of the Miocene Epoch), the climate began to change from wet subtropical to much more arid, grassland conditions. Over about the next three million years, the heavy forest cover gradually died out, and it is in the late stages of this transition period that things become interesting. Our primate ancestors were forced down onto the ground, amidst the most brutal lineup of predators in the world. Lion, leopard, hyena, wild dogs, many in large packs. They are all still there today, just as they were. You may see them on almost any African wildlife show on television, literally ripping prey limb from limb. To get the picture that our ancestors faced, imagine yourself set out at night on the African plain among these predators.
An important set of facts to keep in mind while reading the following is this: Archaeological and paleontological research and field work have shown that bipedal primates first appeared in East Africa approximately five million years ago, roughly at the beginning of the transition from forest to savanna conditions. These creatures would face a difficult transition to savanna living. Some of the other animals would have difficulties, others not. The lions and leopards of the time had forest-dwelling predecessors who, being top predators, had no trouble transitioning to savanna living without having to modify their general body conformation and behaviors. Not so for the hyenas and wild dogs. Inasmuch as small, ground-dwelling predators in the present-day equatorial forest do not run in packs, we surmise that hyenas and wild dogs had to make many adjustments for grassland living. During the wet-arid transition, they might not have been a threat to our pre-humans, but as their pack behavior evolved, they would become a dire threat. We speculate that the cheetah was originally much smaller and more gracile. More on this, later.
Pre-Human Primates
So what would have our direct, pre-human ancestor looked like, at the point where the tree cover began to disappear? Let us begin our hypothesis. It couldn’t have been a ground-dwelling ape. With the tree cover gone, they would have been too slow and clumsy to survive the predation of the big cats. Instead, we hypothesize a smaller, more alert, active and agile primate that looked something like a rhesus or capuchin monkey. Indeed, the first proto-human creatures (Australopithecus) were under five feet tall and had slender, thin-boned body types. On the ground among predators, such a creature would have flight as its sole defense.
The following bit came from the Sigma Xi American Scientist journal sometime in the early 1970s. In East Africa, paleontologists had excavated a sinkhole-like depression that they thought might have been a cave wherein early humans might have lived. Instead, they found large amounts of detritus that had fallen down from above, and scattered among this they found numerous pre-human skulls with few accompanying skeletal bones. They puzzled over this odd fact for some time, until they noticed that many of the skulls had teeth marks on them. After reviewing leopard behavior, it became clear what had happened. Late in the wet-arid transition period, only widely-scattered, small clumps of trees remained, those in low places in the terrain, such as around sinkholes. Leopards carry their prey up into a tree to eat, because otherwise the other predators would move in and eat not only the prey, but the leopard, also. With small prey, leopards consume everything, but the skull is slippery and difficult to hold onto. They tend to accidentally drop some of the skulls, thus their appearance in the sinkhole. Sure enough, when the paleontologists excavated other sinkholes in the region, they found the same thing. It is clear that we were once defenseless prey.
When our primate ancestors were first dropped into this sea of snarling teeth and fangs, they weren’t completely bereft of any useful survival tools. Their tree-dwelling lifestyle equipped them with certain physiological characteristics that were useful then, and still are today in our technological world. First, they had excellent binocular vision because they had to precisely gauge how far away
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