Faulty eyes example of absent ‘intelligent design’
Human bodies are so flawed we’re lucky to be here at all, writes Robin McKie.
TAKE a look in the mirror and examine your eyes. Are they blurry? Bloodshot from last night’s alcoholic excess? Or perhaps they remain clear, bright and healthy? Whatever their state, our optic organs can tell us a great deal — not just about our wellbeing but about the nature of our species and our place in the universe. Are we the product of billions of years of evolution or the handiwork of a divine creator? The eyes have it when we seek answers, it transpires.
Such issues are again making headlines following last week’s remarks by the astronaut Tim Peake, who said he thought the universe could be the result of divine creation. ‘‘I’m not religious [but] it doesn’t necessarily mean that I don’t seriously consider that the universe could have been created from intelligent design,’’ he said.
These views are mild but will nevertheless be seized on by those determined to see the handiwork of God everywhere they look, from the shapes of bananas to the colour of the sky, a habit that is more common in the US than the UK.
And for that Britons should be grateful, for intelligent design is not just wrong; the idea is misguided and intellectually rotten, a point best illustrated in the study of our own bodies — and in particular our eyes.
Creationists say natural selection cannot explain the wonders and complexity of the eye. It must have been designed by a divine entity, they claim. How else can you explain how it coordinates the behaviour of each of its 125 million photoreceptor cells to provide us with vision that has colour and depth? It is too complex to have evolved through random, physiological changes, they say.
In fact, the evolution of the human eye was a basic business. It evolved from simpler versions that in turn evolved from even simpler eyes that in turn evolved from basic light sensors. That is how natural selection operates. It acts on existing features of animals’ bodies and slowly induces change that can eventually result in new species.
But there is a far more important observation to be made about our eyes, it turns out. They are most definitely not organs of perfection, as creationists claim. We get shortsighted, often early in life. We develop glaucoma, cataracts and go blind, as the evolutionary biologist Matan Shelomi has argued. ‘‘Who designed these faulty things? The answer can’t be a God, because a God so incompetent in designing vision sensors isn’t worth worshipping.’’
In other words, the human eye, far from proving there was a divine creator, is a clear pointer to his or her nonexistence.
Nor are our other organs or body processes much better. Females often have great difficulty giving birth because of the large heads of the children they produce, while in males, semen and urine come out of the same hole. Similarly, we have to consume vitamin C to avoid scurvy. Most animals make their own.
‘‘We bite our own cheeks when we eat and our spines decay from early adulthood onwards,’’ adds the anthropologist Simon Underdown of Oxford Brookes University. ‘‘We are a mess. Indeed, we are extremely lucky to be here. Around 70,000 years ago, numbers of Homo sapiens were so reduced — probably to a few thousand people — that we only just survived the environmental perils of the time. Not much intelligent design there then.’’
Indeed, the mistaken idea we were perfectly created to rule a planet designed for our overlordship has become dangerous, as our numbers swell to eight billion and we threaten to destroy global ecosystems, a point emphasised by Douglas Adams when he compared humanity to a puddle.
‘‘If you imagine [that] puddle waking up one morning and thinking, ‘This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn’t it? In fact it fits me staggeringly well, must have been made to have me in it!’
‘‘This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller, frantically hanging on to the notion that everything’s going to be all right, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for.’’
It is an image we should hold on to as our planet and species hurtle towards environmental catastrophe.