Jonathan Cowie looks at the potential dangers and benefits of biological enhancement
The twenty-first century sees the world transformed by human action and humanity with a greater ability to transform its biological self. There are many ways to identify biological success. Of all multi-celled living things, animals are number one in terms of biomass and numbers of both individuals and species. And within the animal kingdom it's the insects that are the champions. Indeed, insects are so successful that the number of insect species is estimated to be roughly around the eight million mark. However, with regards to a single specie in terms of the range of environments inhabited, as well as the area of ecosystem modified by it, then just one stands out as most successful Homo sapiens sapiens: you and I. Of course our population, at a paltry 6 billion (and climbing), does not compare to insects' many trillions, but our permanent habitations can be found at nearly all latitudes and terrestrial altitudes. Our submarines can be found in each of the oceans, there are literally many tens of thousands of us airborne in passenger planes at any one time, and jaunts into space (something no other species does) are so routine that they rarely merit media attention.
The trouble with "success" as any business tycoon, celebrity or even lottery winner will tell you is that it has its problems. There are many problems. Reducing the world to a global village means that epidemics have the potential to affect us all, be it AIDS or flu. Having a successful food supply system for us also provides one for pathogens from salmonella bacteria to BSE prions. And now we are so successful in the biomedical sciences we have the technical ability to change our very biological essence, our genes. Whatever next? Designer babies for a designer future?
Well, first let's clear the dead wood and knock a couple of myths on the head.
The thing with "problems" is that there is often the temptation to finger-point. A common refrain is that Chernobyl, E. coli, global warming, deforestation, ozone holes and so forth, "is them there scientists' fault". Of course, this beggars the fact that it is not "science" an experimental methodology of hypothesis and verification nor scientists that cause problems. It is humanity's biological success. Our billions have to be fed, housed and clothed. We also seek some material pampering. Such are our numbers that almost inevitably waste, environmental impact and species extinction follow. Science is implicated indirectly in that technology arises out of scientific understanding, but it is the use of technology (not necessarily even the technology itself and certainly not science) that can be a problem. For instance, intensive-farming technology can encourage the spread of agricultural disease as well as feed the masses. It's just like the use of fire, which may be employed to cook food and warm dwellings as opposed to burning them down. So man-made chemicals can be used to preserve food or used as medicines just as they can (inadvertently) cause holes in the ozone.
The scale of our biological success is encapsulated in the way our global population has grown. Everyone knows that the population has grown: it has risen from two billion to six billion over the past century or so. What is frequently forgotten is the bigger picture. Prior to the nineteenth century the world population was barely growing and never exceeded one billion. But once the fruits of the industrial revolution were realised, our population soared. Indeed, for part of the twentieth century population grew at a super-exponential rate: it grew like your savings account would if you received interest on your interest within the same financial year.
So here at the dawn of the twenty-first century we (society and biologists) face two critical questions. Can we preserve the Earth? Can we preserve the biological essence that makes us human?
Naturally we can take steps to preserve the Earth; we can aim at sustainability and undertake biological conservation, should we wish, but we have to be prepared to pay for it. Here we need to spend our money carefully. Importantly we need to appreciate what it is we are trying to do. Preserving things as they are, or even going back to swathes of countryside as it was before the industrial revolution, is not necessarily natural. In fact it is positively unnatural.
For example, what many consider the natural state of the UK for much of the past 1,000 years was in fact shaped by human action with woodland being felled, land drained and heath lands burned. Go back 100,000 years indeed all but the last 10,000 years and the UK has been beneath an ice sheet. Go back further and there have been as great a series of changes: around a score of "ice ages" dominate brief warm ones over the past two million years. This cool-warm-cool series is a natural succession of evolutionary hoops enabling one primate to become human through natural progression.
On the scale of tens of millions of years the Earth has experienced a gradual cooling and on a scale of tens to hundreds of millions of years the Earth has seen the rise and fall of many species of plants and animals to some sort of biological prominence within the biosphere: the Triassic to Cretaceous age of the dinosaurs being the most famous to non-biologists. In this context, what is natural? What exactly are we trying to preserve? The Earth's biosphere is naturally subject to change.
Some may argue that human-induced global warming means that most of our nature reserves are in the wrong place for the species they are trying to conserve and that this is a problem of our making. True, but even if we weren't interfering with the climate then the natural trend would have been the other way, a cooling, and we would still have a similar problem!
Therefore, while ethically we desperately need to stop over-fishing and deforestation, what is our overall biological aim when we sit down to plan biological conservation? We need to recognise that the seemingly uniform green of natural grassland does not consist of just one species of grass. Equally, we need to recognise that some rare species are in nature naturally rare. We desperately need to think about what is the nature of being natural. If we do not, then we could end up thinking we have saved the planet when in fact all we have done is to create a biosphere from our own minds and unwittingly lost innumerable species in the process.
If the natural environment is naturally subject to change then what about us humans? We Homo sapiens sapiens are animals and subject to the natural laws governing biology just as any other. That we have a developed sentience does not make us independent of evolutionary pressures: it is a result of them. We might delude ourselves that our urban lives and twenty-first century technology has eliminated the pressures of evolutionary selection, but it has not: it has merely changed them. We tend to forget just how late we have arrived on the planetary scene. Human civilisation first arose just 10,000 years ago. If the length of your arm represents the entire history of our planet then on that scale human civilisation is just a couple of micrometres at the very end of your finger; one tenth of the thickness of a human hair. Our presence on the planet, our success, has been fleetingly brief.
Against this perspective it is easy to see just how unrealistic it is to expect humanity (either biologically or in any philosophical sense) to remain the same or for that matter for us, in our current form, to remain successful. The question then becomes not whether it would be wrong to modify our genetic make-up for it will change with or without us but whether we should help manage the change ourselves?
This then is the proverbial $10,000 question: though given the magnitude of annual expenditure on biomedicine worldwide perhaps it should be the $10 billion dollar question.
2001 saw us roughly draft the human genome and this decade will see the task completed in detail. Subsequent decades will witness the charting of gene function (which gene codes for green eyes and so forth) and before long we will have the ability technically at least to edit genetic make-up. This can sound sinister, and indeed would be if we were trying to create some sort of master race or humans as described in Aldous Huxley's Brave New World. But equally it can be for the good. Already we can screen for Down's Syndrome and a few other genetic disorders, but we almost certainly will be able, should we wish, to begin to screen for genetic disease such as cystic fibrosis or a propensity for cancer, even heart disease and so forth, within the gene pool.
Question: would this be wrong? The answer must be no, but then it comes down to what we do with the information. Should we knowingly allow human suffering to be conceived in the first place (so removing any opposition to the right of abortion for such reasons)?
Such questions are not for biologists to answer. Now this is not a cop out. Biologists are people too and they can contribute to the debate as individuals in their own right. What biology (or biologists as professional experts) can do is to illuminate this public debate, to make it informed.
Personally speaking, I am not frightened by the understanding and potential modern biology brings. This is not to dismiss or accept such potential. What does concern me is whether we will manage our bio-sphere as a whole properly. Whether we will or not, in a humane and ethical way, manage our own genetic change as well as that of other species? Both these issues of environment and humanity are important; both are interconnected since we need an ecologically sound environment in which to exist healthily. Biology can help us answer these questions. If we don't properly meet such questions head on, we may very well find out that one of the most endangered species on the planet today is our own, no matter how biologically successful we have been to date.