Transcript of The Big Question: Why Are We Here?
The human race is one of the wonders of the universe. We may be unique. And of all our remarkable properties one stands out. It is that we are restlessly drawn to ask questions like: "Why are we here?" and "What is the purpose of life?"
The great civilizations and cultures of the past, came up with various answers, all unsatisfying because they were made up, rather than being properly investigated. So, can science come up with something better? I think so. It may sound presumptuous, but I believe that science CAN tell us why we are here. It can tell us the purpose of human existence.
The answer is an optimistic and an inspiring one. Why are we here? For most of the 500,000 years of human existence, we have been unable to answer the question of why we are here. It was only 150 years ago that science first tried to find an answer.
In 1859, Charles Darwin published a book which changed the world. When Darwin first got up the courage to publish the book, "Origin of Species", it shook the spiritual foundations of his age. Victorians had to come to grips with an entirely new set of unwelcome relations. We are over it now. Most of us are happy to teach our children that we are desccended from apes. We ARE apes. But I believe that Darwin has another message for us which could be frightening if we let ourselves be intimidated. But it's exciting and uplifting, if we have the courage to face it.
Not only did Darwin find the answer to the question of how did we come to exist, I believe his theory provides us with the answer we are probably only likely to get to the ultimate question - Why we exist - What is the purpose of life.
There are some 10 million species on earth. The displays here at the Natural History Museum at Oxford, represent only a tiny fraction of them. But before Darwin, no one knew how animals came to be so varied, so complex. Every last detail of every last creature's body and behaviour, seems exquisitely tailored to its environment. The platypus' webbed feet are built for efficient paddling and its duck bill is a radar electrically sensing its prey in the mud. As for the cheetah, its sleek and nimble body is a formidable machine for catching prey.
For centuries people tried to understand why animals were so perfectly equipped for their tasks. They assumed that there was only one explanation, the natural world was designed and that designer was god. The Reverand William Paley, writing half a century before Darwin, put the case with his famous "Watchmaker Argument."
Imagine, Paley said, taking a walk on the heath. If you came across a rock, you wouldn't be surprised. The rock could have lain there forever. It doesn't need explaining. But a watch on the heath would demand an explanation. It's existence and complexity would require a big explanation. The intricate precision of the cogs, the accuracy of which it keeps time, these are evidence that the watch must have had a designer. A watchmaker. Surely, Paley went on, no less is required to explain the even greater complexities of nature. There must be a divine watchmaker.
If I had read Paley in 1802, I might have agreed with him. But now things are very different. Charles Darwin has given us a much neater, more self-sufficient and therefore more satisfying explanation. Darwin argued that there was no designer. And at first sight this seemed like a ridiculous idea. Like Paley's watch, plants and animals appear to be staggeringly improbable combinations of their component parts all working towards one end. Take the nuts, cogs, bolts and springs of a watch and recombine them at random as many times as you like, only one arrangement tells the time. As the astronomer Fred Hoyle put it, the possibility that the parts of a living organism would spontaneously come together by sheer luck, is about as likely as a hurricane blowing through a scrap heap and spontaneously assembling a boeing 747.
So, how does nature do it? Even a fly is arguably more complex than a 747. If there is no designer, how did the complexity and variety of life come about? There's a clue as to how the process works in many people's back gardens.
There aren't many times when the pigeon has played a starring role in science, but it was this common place bird, that started Darwin on his journey of discovery. Darwin noticed that pigeon fanciers were able to breed new varieties. By carefully selecting mates, they had turned the ordinary pigeon into dozens of weird looking birds with weird sounding names. There were fantails, jacobins, short-faced tumblers and a horde of other varieties. Darwin knew that these all originated from one bird, the rock dove. And the pigeon breeder, Pat Pratt, can demonstrate that Darwin was right.
Pat Pratt - "If the fancy pigeons are allowed to breed as they like without any intervention at all from us, then at no time at all, they all revert to this wild type. Usually the first and second crosses from our fancy pigeons will show some type of return tothe drab blue colouring of the rock dove."
The effort to create different types is called artificial selection. And perhaps, Darwin reasoned, a similar process could occur in the wild. But how could selection occur in nature without a divine pigeon breeder to do the work?
The work of natural selection is classically illustrated by the finches that Darwin found on the Galapagos Islands. There are some 13 species all with different beaks. Yet, these varieties all evolved from one successful species which arrived from the mainland with one type of beak. One now behaves like a woodpecker, using a cactus spine to hunt for grubs. Another, now feeds on ticks living on giant tortoises while a third, the vampire finch, feeds on the blood of seabirds. These are all activities requiring different types of beak. Natural selection is about survival. The beaks changed, because the changes helped the finches to survive. And there wasn't a designer in sight.
When Darwin first explained evolution by natural selection, many people either couldn't, or wouldn't grasp it. I, myself, flatly refused to believe it when I first heard it as a child. For Darwin's theory to succeed, it had to explain both the wonderful variety of nature, and its astonishing conplexity. It does both with the utmost elegance.
My colleague, George Mc Gavin, has devised an experiment to show how natural selection works in practice. It explains how insects acquire their camoflage. They do it tiny bit by tiny bit.
George Mc Gavin - "What we have here is an artificial woodland floor on which I have placed a variety of insects. Some of the insects are very easy to see. Some of the insects are not so easy to see, and a few of them are extremely hard to see. Ok (to children), what we are going to pretend is that we are in a woodland and you are hungry birds out looking for insects. So, if you see something that you might want to eat. Say, I can see an insect. Who can see an insect? Me! Me! How many can you see? 3? 2? I can't see any.. "
The children play the role of predators. They show that even a little camoflage gives an insect some protection. So long as its predators don't get too close. If you are obvious, your chances of being eaten are really high. And therefore over time, small changes would make you not so obvious would be slected and passed on and so at the end of thousands of years of evolution, the end result will be an insect which is extremely well hidden in its background. The success of those hidden insects shows how natural selection rewards even tiny changes. The process of natural selection explains how simple structures over millions of years eventually evolved into complex, astonishing creatures, like the dinosaurs. Or us.
But natural selection is not some kind of awards ceremony, where nature applauds interesting new genetic mutations. It's not nature's fashion show. It's a competition to the death. Each individual within every species competes in the bloodthirsty and harsh real world for access to resources and for opportunities to reproduce. Natural selection is all about living long enough to pass on your genes.
Darwin realised that wild animals compete to survive and that more are born than the food supply can sustain. Inevitably, many die young, or they fail to reproduce. Amidst this wildspread slaughter, every animal fights a relentless battle for survival. In the natural struggle for existence, some variants were better at surviving than others. And they, passed their good qualities onto the future. Natural selection explains how we got to where we are now.
Does it also suggest to you a dark and troubling answer to the question - Why we are here? Natural selection suggests that we, like all other animals are survival machines. We are here only long enough to compete to pass on our genes. This seems to be the purpose of our lives and the reason we are here. But can this really be the only purpose of human existence? I don't think so. Darwin's remarkable theory offers a second meaning to our purpose. It's an inspiring one, which accords more fully with out own view of our better selves.
It stems from the curious observation that we humans seem to be breaking Darwin's rules. Human behaviour in the 21st century, seems to have nothing to do with what we call natural selection. Evolution may explain how humans came into the world, but it doesn't shed much light on the way we lead our lives today. Most of our energy goes into projects which seem to have nothing to do with the goals of survival or reproduction. We neither feel nor act as if we were driven by evolutionary complusion.
We seem to have freed ourselves from the need to spend all our time propogating our selfish genes. We have many other goals which take our time and energy. We explore the world around us. We create objects for their aesthetic beauty. We pursue hobbies for the sake of fun. And when we have sex, we defy our genes with contraception. If only they could think, our genes would be aghast at all this.
I, personally, am delighted that our big brains gave us the freedom to defy our selfish genes. The unrefined world of natural selection, is not the kind of world I want to live in. The beauty and purposeful elegance of cheetahs and gazelles is wrought at huge cost in the blood and suffering of countless ancestors on both sides. But IF the ultimate purpose of our existence is the narrow Darwinian one of propagating our genes, how can we defy them?
Ironically enough, the things that freed us from our genes, were also the result of natural selection. And it all began, millions of years ago, in Africa. At the time, humans were still prey. Surrounded by predators, we evolved survival tools. And the most important of these was the brain. Natural selection drove the development of the human brain. It did so with no more purpose than it drove the development of the tail of the peacock, or the speed of the cheetah.
The genetic advantage was rewarded and our brains got bigger. They didn't just be bigger, they became different. We evolved the ability to do something no other animal could do. Set goals. Find a new waterhole, plan a hunt, set aside food for the winter and we learn to adapt and change our thoughts. What natural selection built into us in Africa, was the capacity to seek, to strive, to set up short term goals in the service of long term goals and eventually, the capacity for foresight. Bigger brains allowed our individual ancestors to compete more effectively, and then, something unprescedented happened.
A brain arose that was able to look around the world, and ask, perhaps for the very first time, the question, WHY? Why are we here? We were no longer content to do what nature told us. We began to think about other goals that suited us. And we had a tool to express those goals - language. Speech let's us share goals. And a creature able to communicate its goals begins to think purposefully. Act purposefully. Create purposefully. And even more amazing, through language our goals can take on a purpose beyond the life of any one individual. One inventor can produce the wheel. Using language, generations of inventors share in the goal of fast cars and produce the modern one. Technology is human goal seeking writ large. And once human beings set themselves to a goal, they force the pace of evolution themselves.
This is an entirely new kind of evolution, non-genetic evolution. Advancing at the speed at maybe a million times faster than the genetic evolution which it resembles. We see its products everywhere in the technology of the modern world. We have created a technological world that enables us to move far beyond the dictates of nature. And it allows us to do astonishing things. We alleviate hunger with new strains of crops. Predict the weather with high speed computers and cure diseases with pharmecuticals. Through technology, we have filled the world with purposeful creations.
But technology does something else. It breeds an odd habit of thought. An animal who invents, will look at the world in a different way than any other animal. We see the world through "purpose coloured spectacles" . Because WE create things for a purpose, in the past we assumed that there was purposeful design in nature too. There wasn't as it happens. It took Darwin to realize this. He looked deep into the heart of nature and discovered a beautiful mechanism which blindly simulates the illusion of purpose. For the first time, an evolved creature had seen beneath nature's veil and worked out what nature was really up to.
And it is this spirit of enquiry that drove Darwin that gives our life meaning. It still drives us today. Powered by our technical capacity, our flexible behaviour and our rapid communication of new ideas; we've burst out beyong the confines of our atmosphere, to explore new worlds. And our minds have voyaged even further. We have looked across the deserted vacuum of space to the distant galaxies. Which means we have looked backwards in time, to the very birth of the universe and of time itself. At the other extreme, we have looked deep into the atom, at the strangeness of subatomic particles and most amazing of all, we have disected the living cell, finally unravelling the digital codes of the genes themselves. And still, we are not satisfied. We reach out in our search for meaning until we realize that it is we, who actually provide the purpose in a universe which otherwise would have none. Nothing else can do it. At least nothing we know of.
In a small, otherwise unimportant corner of the universe, a birth is celebrated. The birth of deliberate purpose. Planning, design, foresight. For all we know, it may be an unprecedented event. We have no evidence that it has ever occurred anywhere else, and after we are gone, it may never happen anywhere ever again. We can leave behind the ruthlessness, the waste, the callousness of natural selection. Our brains, our language, our technology, make us capable of forward planning. We can set up new purposes of our own. And among these new goals can be the complete understanding of the universe in which we live. A new kind of purpose is involved in the universe, it resides in us.
When I hear somebody sigh, "Life is hard," I am always tempted to ask, "Compared to what? - Sydney Harris
Richard Dawkins , meaning of life , evolution , natural selection , artificial selection , selective breeding , purpose of life , genetics , genes, Charles Darwin
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