One of the most fascinating aspects of human evolution, is why did it begin? What happened deep in the time line of humanity that was so radical, so different to what all the other primates were doing that it was to kick start the evolution of our brains that so clearly sets apart from the other primates of that time?
The difference between Humans and our primate cousins is not limited to out metal capacity either. We look different too. We are tall, erect, bipedal creatures with relative hairless bodies and a physical less dense structure. Plus we have a highly developed language. It is these differences that I will be exploring in this article.
Ask any zoo keeper and they will tell you that even a small chimpanzee is far stronger than the average man, their muscles being so much more compact then our own. Their bones too are heavier and denser to. Put simply, pound for pound Primates pack a hell of a lot more whack for their buck.
Another important difference between humans and Primates is that we are the only primates with a layer of fat just under our skin. Why?
It is widely reckoned that the primates that we evolved from first came down from the trees to cross areas of savannah in order to reach other food rich stands of trees. This may have happened because of a thinning out of forest due to ecological change forcing our ancestors to either "Adapt or die."
Trees have always been a good habitat for Primates. They offer food, shelter from the weather and a retreat from predators. The grass planes developing around these islands of trees would have been prime predator hunting grounds. In order to cross these grasslands the ability so stand erect and see over the grasses would have been a distinct advantage. Not just to pre-empt an attack from a predator either but also as a means of navigation. (It helps to see where you are going) It's even possible to imagine these early beings utilising a stick or staff as a means to aid standing.
But what happened then? How did the other changes come about? It has been shown that early hominids set up home in caves along the coast of Africa. And I believe it is here that we find the answers to some of the other differences between us and the other primates, particularly with reference to our lack of hair, body fat and densities.
An Ape that that has begun the evolutions change to standing and walking and that has already started to use tools such as sticks to feed on termite and ants as chimpanzees do probably took his skills into the shallow waters of the seas and rivers and used them to catch fish, either by spearing them or perhaps scooping them out of the water, much as a bear might do. Of course having evolved hands from life in the tress our Ape would have an advantage over the bear when it came to grabbing or scooping for fish.
The importance of this interaction with water could effect many of the evolutionary changes that we are talking about. Standing in water looking for fish would encourage if not instigate an evolutionary change to standing erect. Long shaggy hair would be a disadvantage when spending a lot of time in the water as it would slow your movements down and make you heavier when saturated, not to mention taking you longer to dry out after leaving the water. So a shedding of the body hair could easily be expected. Our strange body fat, not seen in other Great Apes would evolve in our species much as it has done in Seal lions, as a means of insulating our bodies against the heat sucking waters. But the greatest of all our evolutionary gains, our brains, would have been fed on the rich, brain feeding omega oils present in the fish we were now eating and this combined with land meat scavenged or hunted as well as the vitamins colleted in the fruits and roots foraged would have given our spices a range of vitamins, iron and trace elements not available to other species.
Evolution is a long and slow path, gently edging a species in one direction or another. Millennia after millennia it trudges along but occasionally it is punctuated by a sudden jerk. Something happens which forces a species to either evolve or fall to extinction. The causes of these jerks are hard to identify. But there was one catastrophe which man had to survive which we can identify. The ice age. It is reckoned that at one point during the last Ice age human numbers dropped to as low as eight thousand individuals. It is altogether likely that is was only the luckiest and the smartest of the human tribes that survived this time. The effect of the Ice age was to boil the human race down to the brightest and the bravest and that it was this radically culled pot that led to the next stage of humanity to be born, Civilization.