Professor Richard Dawkins
Our starting point must be the fundamental logic of Darwinism itself. Simply stated, everybody has ancestors but not everybody has descendants. We have all inherited genes for being good at becoming an ancestor. Ancestry is the ultimate Darwinian value. In a purely Darwinian world, all other values are subsidiary and, synonymously, gene survival is the ultimate Darwinian value. So, as a first expectation, all animals and plants can be expected to work ceaselessly for the long-term survival of the genes that ride inside them. The world is divided into those for whom the simple logic of this is as clear as daylight and those who, no matter how many times it is explained to them, just don’t get it.
Alfred Russell Wallace put the problem in a letter to his co-discoverer of natural selection, "My dear Darwin, I have been so repeatedly struck by the utter inability of numbers of intelligent persons to see clearly, or at all, the self-acting and necessary effects of natural selection". Those who don’t get it either assume that there must be some kind of personal agent in the background to do natural selection’s choosing; or they wonder why individuals should value the survival of their own genes, rather than, for instance, the survival of their species, or the survival of the ecosystem of which they are a part. After all, say the second group of people, if the species or the ecosystem don’t survive, nor will the individual. So it must be in their interest to value the species and the ecosystem. As we shall see, this is faulty reasoning. If only it were true, the values of sustainability would simply be built into us by natural selection. What an appealing thought that would be.
Who decides, then, that gene survival is the ultimate value? Nobody decides, and there is no personal agent doing the choosing. It all just follows automatically from the fact that genes reside in the bodies that they build and are the only things (in the form of coded copies) that reliably persist down the generations. This is the modern version of the point Wallace was making with his apt phrase ‘self- acting’. Individuals are not miraculously nor cognitively inspired with values and goals that will guide them in the paths of gene survival. Only the past can have an influence, not the future. Animals behave as if striving for the future values of the genes simply and solely because they bear and are influenced by genes that survived through ancestral generations in the past. Those ancestors that, in their own time, behaved as if they valued whatever was conducive to the future survival of their genes, have bequeathed those very genes to their descendants. So their descendants behave as if they, in their turn, value the future survival of their genes. It is an entirely unpremeditated, self-acting process, which works as long as future conditions are tolerably similar to past conditions. If they are not, the result is often extinction of the species. But it is not differential species extinction itself which constitutes the process of natural selection. If you understand that, then you understand Darwinism in my view. The word Darwinism, by the way, was coined by the ever-generous Wallace.
I am going to continue my Darwinian analysis of values using bones as my example for the moment because they are unlikely to ruffle political or other human hackles. It is not that I mind ruffling hackles per se but, in this case, it would be a distraction and I do mind distractions that get in the way of clarity.
Bones are not perfect. They sometimes break. A wild animal that breaks its leg is unlikely to survive in the harsh competitive world of nature. It will be vulnerable to predators, unable to catch prey, whatever it might be. So, why doesn’t natural selection thicken bones so that they never break? We humans, by artificial selection, could breed a race of dogs whose leg bones were so stout that they literally never broke. So why doesn’t nature do the same? The answer of course is costs – economic costs – and this implies a system of Darwinian values.
Engineers and architects are never asked to build unbreakable structures, impregnable walls, bridges that can’t fall down, trains that can’t come off the rails. Instead, the engineer is given a monetary budget and asked to do the best he can according to certain criteria within that constraint. Or he may be told the bridge must bear a weight of some number of tons and must withstand gales three times more forceful than the worst ever recorded in this area. Now go ahead and design the cheapest bridge you can that meets these specifications. Safety factors in engineering imply that we put a monetary value on human life. If we don’t like that, that’s tough – there’s no other way.
Designers of civil airliners are more risk-averse than designers of military aircraft. All aircraft and ground control facilities could be made safer if more money was spent More redundancy could be built into control systems. The number of flying hours demanded of pilots could be increased, and so on. Recent events may make us wish that safety checks on aircraft and security checks on passengers were more stringent and time-consuming, and they have recently become so. The balance has shifted slightly, but there will always be cost constraints on how stringent they can become. We are prepared to pay a lot of money for human safety, but not infinite amounts. Like it or not, we are forced to put monetary value on human life. People who think it somehow wicked to talk about putting monetary value on human life, people who emotionally declare that a single human life has infinite value, are living in cloud cuckoo land.
Darwinian selection, too, optimises within economic limits and can be said to have values in the same sense. My colleague Nicholas Humphrey, continues this argument with another analogy from engineering. Henry Ford, it is said, commissioned a survey of the scrap yards of America to find out if there were parts of the Model T which never failed. His inspectors came back with reports of almost every kind of breakdown – axles, brakes, pistons – all were liable to go wrong. But they drew attention to one notable exception – the king pins of the scrapped cars invariably had years of life left in them. With ruthless logic, Ford concluded that the king pins on the Model T were too good for their job and ordered that, in future, they should be made to an inferior specification. Nature, Humphrey concludes, is surely at least as careful an economist as Henry Ford. Humphrey applied his lesson to the evolution of intelligence, but we can apply it to bones or anything else.
Imagine that we commissioned a survey of the corpses of gibbons, and looked to see whether there are any bones that never break. Suppose we found that every bone in the body breaks at some time or another, with one exception – let's say it's the thigh bone, the femur, which has never been known to break? Henry Ford would be in no doubt – in future, the femur must be made to an inferior specification – and natural selection would agree. Individuals with slightly thinner femurs, who have diverted the material saved into some other purpose, say building up other bones, would survive, or at least reproduce, more successfully. In a machine or an animal, the simplified ideal is that all the parts should wear out simultaneously. If there is one part that consistently has years of life left in it after the others have worn out, then it is over-designed. Material that went into building it should instead have been diverted to other parts. If there is one part that consistently wears out before everything else, then it is under-designed and should be reinforced, using materials taken away from the over-designed parts. Natural selection will tend to uphold an equilibration rule – rob from strong bones to pay weak ones until all are of equal strength.
I said that that's an over simplification, the reason being that not all the bits of an animal or a machine are equally important. That’s why in-flight entertainment systems in airliners go wrong, thankfully, more often than rudders or jet engines. A gibbon, unlike a human, might be able to afford a broken leg better than a broken arm, because its way of life depends on its swinging through the trees. So a gibbon with a broken leg might just survive to have another child, whilst a gibbon with a broken arm probably wouldn’t. So the equilibration rule I mentioned has to be tempered – rob from strong bones to pay weak ones, until you have equalised the risks to your survival accruing from breakages in all parts of your skeleton.
But who is the ‘you’ that we are talking about in giving these instructions? Obviously it is not an individual gibbon. The ‘you’ is an abstraction. You can think of it as a lineage of gibbons in ancestor-descendant relation to one another, represented by the genes that they share. As the lineage progresses, ancestors whose genes make the right adjustments survive to leave descendants who inherit those correctly equilibrated genes. The genes that we see in the world tend to be the ones that get the balance right, because they have survived through a long line of successful ancestors, who have not suffered the breakage of under-designed bones, nor the waste of over-designed bones.
Sustainability Doesn’t Come Naturally: A Darwinian Perspective on Values: