Modern man: survival of the fittest or just a bit of luck?
The scientific briefing with Luke Boulter
This week it surfaced in the news that a letter written by Charles Darwin - one of the original proponents in the theory of evolution - is to be auctioned at Sotheby’s. The letter was written in October 1980 in the aftermath of his landmark work Origin of Species, and shows Darwin’s modest view on what he had proposed and his lack of shock that his peers were dubious about this ‘new’ idea.
Natural selection and the theory of evolution is still seen as one of the most revolutionary pieces of scientific thinking, and is classically marked as the point where human creation found a viable scientific footing. Human evolution is a subject which is often not greatly considered, but one which is critically important. It gives us a glimpse of where we have come from, who we are and ultimately where we may, or indeed may not, end up. Human evolution is also a contentious subject not only for the obvious religious implications, but also for being shrouded in arrogance, lies and treachery.
Before I begin the story of human evolution, I apologise for some of the scientific names used, and for the unscientific nature of the information, but when compiling information such as this the majority of it is speculative. As far as we know, humans began as a four legged ape-like creature, that to be honest is wholly unremarkable, known as Proconsul. This creature wandered across the increasingly arid regions of what is now Africa. The original and best Proconsul fossils were found in the 1930s and still reside in London’s Natural History museum. Proconsul is similar in both form and characteristics to modern day monkeys, as it has a long slim body, rather than the broad chest of humans and other apes. There were many species of Proconsul living about 20 million years ago, so the fossil record for these creatures is vast.
It is believed that a group of creatures known as the Dryopithecines were the next link in our evolution. Members of this group were effectively Apes with reduced teeth, indeed this is the first point in our evolution where we see a vertical face, with no muzzle, - something that we take for granted. There were many Dryopithecines, but only one is really relevant to our story: Kenyapithecus, the first real ancestor of humans.
Australopithecus seems to be the next in the path to humanity. This ape like creature has similar jaw to ours, and there is significant evidence to suggest that Australopithecus walked upright, since it has similar feet to us.
So, thus far, we have a flat-faced ape-like creature that can walk upright. Okay, I know I’m asking a lot, but stretch your imagination a bit and you can almost see how it only takes a few simple steps from Australopithecus to a recognisable modern day human.
When I say ‘simple’, all we have to do is increase our brain size. The best analogy I can think of is to imagine a single measure of whisky: it has a volume of 25ml, so it would take 60 measures to fill the volume of our brain, but it would only take about 20 to fill the volume of Australopithecus. We have therefore actually managed to increase our brain volume by 3 times in the space of 2.5 million years.
Our most famous ancestor is perhaps Homo erectus. Unlike its name suggests, it was not the first of the upright hominids, but is a very close relative of us, having a similar brain size and utilising relatively complex stone tools.
Homo erectus is the first case where archaeological evidence has been found to suggest a global population… The hominids, at last, after 19 million years, had ventured out of Africa!
The most exciting race of human evolution has only really lasted a few hundred thousand years. This is the race between Homo sapiens and Homo neanderthalensis.
The Neanderthals, as they are more commonly known, were our most abundant contemporaries (our other contemporary being Homo floresiensis, which was discovered, confined to the island Flores in 2003). The Neanderthals were remarkably similar to us, and, in many cases, Homo sapiens and Homo neanderthalis are classed as mere subsets of the same species. Modern reconstructions of the Neanderthals suggest that they would look like a thickly set modern human. They would have slightly more prominent ridges above the eye, but if you dressed them in clothes then there would be very little difference between them and us. Genetic evidence also shows that Neanderthals are very close relations, diverging from us only half a million years ago.
It is not just in the physical appearance that Neanderthals were like us; there is evidence of a musical flute, and fire, both of which are indicative of a complex society. There is also evidence that the Neanderthals buried their dead, which has no practical significance except that the deceased is not left to be eaten. This, coupled with sites where flowers have been thrown onto the corpse, suggests that there is a complex social ritual and, without stressing the point too strongly, there may even be evidence of belief.
So then, why is it us who grace this earth rather than the Neanderthals or another species? Well, to begin with, we are intelligent - disproportionally so, in fact: our brains are too big for our bodies and that gave us an advantage. We were lighter than the Neanderthals, so when the time came that fighting was no longer an option, we could flee with more ease.
The most convincing argument for our survival, though, is our willingness to adapt. Homo sapiens are wanderers, we migrate even now, and always have. When food is scarce or the climate takes a turn for the worse we move. The Neanderthals, or so it is believed, were much more homely, fighting it out whenever times and resources changed.
Ultimately, though, I’d like to suggest that is was just old fashioned luck; somewhere, each of our ancestors was in the right place at the right time, with the right amount of fur. From an evolutionary standpoint we are nothing more than naked apes, but naked apes that have made a population of over 6 billion from an original stock of 100,000 or so.
