An ardent objection common to human enhancement and transhumanism is that it is both perilous and foolhardy to try to ‘play God’, or to question the wisdom of Mother Nature. As with most mental shortcuts, there is some truth in the ‘nature knows best’ argument. Cognitive enhancement, perhaps the most challenging and promising of all, is no mean feat. Naïve intervention into the mechanisms of the most complex system in the known universe could disrupt the delicately poised equilibrium struck by evolution over millions of years with unknown consequences.
"What are we here for if not to enjoy life eternal, solve what problems we can, give light, peace and joy to our fellow-man, and leave this dear fucked-up planet a little healthier than when we were born." - Henry Miller
Undoubtedly caution should be deployed, but isn’t outright disregard for the ‘unnatural’ both hasty and hypocritical? Tool making and technology is one of the things that sets human beings apart.
When prying more closely into the arguments made by advocates of the ‘nature knows best’ argument, a common retort to enhancement goes like this: Evolution has made delicate trade-offs between features. If the proposed intervention would result in an enhancement, then why hasn’t it already evolved?
To quote Biologist Francis Jacob, evolution is a 'tinkerer, not an engineer’. Evolution is a blind pilot; it applies ad hoc solutions to immediate problems. There are then several reasons why a particular trait has not evolved. Perhaps the time-scales required for a particular adaptation has not been reached. Perhaps it is due to stasis in a local optimum - the mutations required to evolve a beneficial trait later on don’t immediately confer a fitness advantage so are never able to proliferate. Or perhaps there simply aren’t the means available to develop certain traits that would in fact be optimal, like diamond tooth enamel or a titanium skeleton.
Nick Bostrom and Anders Sandberg suggests three instances when we can deem it best, or at least safe, to proceed with enhancement and disregard the ‘nature knows best’ argument: changed trade-offs, value discordance and evolutionary restrictions all signify instances where the ‘nature knows best’ argument can be disregarded as in these cases nature does not know best.
Evolution strikes trade-offs, and how optimal a trade-off is contingent on the environment; when the environment changes which trade-offs are optimal changes. Rapid blood coagulation is optimal for a hunter-gatherer at risk of being mortally wounded and bleeding to death, but for modern man the risk of mortal wounding is relatively slim, whereas heart disease, the biggest killer in the world, is relatively high risk and a direct result of having the thicker blood that was adaptive to our ancestors. Examples abound. DNA repair is metabolically costly and therefore impractical in the ancestral environment, but needn't be in the modern world.
There is another reason we might want to meddle with the work evolution has done so far; a discordance between human values and the values of evolution. Emotions were not sculpted by evolution to promote happiness and well-being, rather they are sculpted and calibrated to propagate genes. The interests of unconscious, selfishly propagating gene and of the modern day man are quite different. It’s a sobering thought to think it could have turned out a lot worse. Pain is one of the primary motivators, but it is not the only motivator. A world where minimisation of pain is the only evolutionarily determined motivator doesn’t bear thinking about.
The interests of the selfish gene and of human beings needn’t intersect, but luckily for us they often do. Evolution and human beings alike value good health, good eyesight, etc. But there are many areas where previously adaptive traits are no longer adaptive, nor are they desirable. On the individual level, psychological and physical pain are such as sexual jealousy, status envy, ennui, anxiety, boredom and sadness may have all been adaptive emotions in the past but now serve no adaptive advantage and are experientially unpleasant. Are these emotions worth preserving?
Fundamentally altering these emotions is a particularly contentious issue as it challenges what it means to be human, but it is important to remember human nature is a product of evolutionary environment, and is therefore essentially arbitrary; sanctifying and preserving every facet may be an indefensible sentimentality, misaligned with our true preferences and a hindrance to human flourishing. Such sentimentality may hinder the development of new nature more in tune with what we value, and perhaps what we should value. Extended altruism, conscientiousness and honesty, taking joy in others success and flourishing are all traits that are desirable in modern day society to facilitate human flourishing.
A reasonable question might be that if these traits would benefit everyone, why haven’t they evolved already? In the ancestral environment, too much compassion could be maladaptive because it is liable to be taken advantage of by opportunistic enemies. This may still be true to some extent, and we would want to be especially careful not to make ourselves vulnerable, but civilised society has developed alternatives to regulate negative behaviours and a more compassionate world as a whole, while safeguarding against free riders and malicious adversaries, is surely a desirable goal. In an age when world war could end the human race, and increasingly technology could provide malevolent individuals with enormous destructive power, it's arguable that moral enhancement is a moral imperative.
Tools that evolution lacked are now accessible. There are great limitations on what evolution can do. Evolution is an ad hoc process that uses the best materials at its disposal for whatever purpose, but we may be able to do better with access to tools that evolution lacked. Biology is limited in what it can build. DNA can only work with proteins and it is therefore very unlikely for any organism to diamond tooth enamel or a titanium skeleton, even if these traits would have conferred a fitness advantage. Furthermore, it is unlikely that evolution could have evolved silicon computational chips to improve cognitive performance, regardless of the cognitive benefits that may be conferred by such chips. A theoretical design for artificial red blood cells has been published which, as it is not limited by the constraints of biology, could enable performance far outside the range of natural red blood cells. This one of many of desirable enhancements that evolution is fundamentally incapable of producing.
Even without a fundamental inability, evolution gets stuck on solutions that are locally, but not globally, optimal. A small change could make things worse, but a big change could make them better. Being trapped in a local optimum is especially likely to account for phylogenetic traits that incur a fitness penalty in their intermediary stages of evolution. The human appendix is a good example. It would be better if it wasn’t there at all, but smaller appendices increase the risk of appendicitis. Therefore, unless evolution can find a way of doing away with the appendix in one fell swoop, it may not be able to dispense of the organ, and so it remains. There are other examples of sub-optimality in sexual selection. In order to woo peahens, peacocks invest heavily in plumage, as this is a symbol of good health and is thus sexually selected for. This cumbersome tail makes them more vulnerable to predators, but it is not clear there is a way for evolution to evolve away from this suboptimal state. Problems that were intractable to blind evolution could be solved by a genetic engineer; evolution works on an ad hoc basis, a human engineer can work backwards.
Many people have a preference for ‘natural’ things. ‘Unnatural’ interventions are often viewed with suspicion. In circumstances where the trade offs have changed, there is discordance with human values and the values of evolution, or when evolution has faced restrictions preventing a better adaptation, then there is good reason to override the ‘wisdom of nature’ intuition as these three categories correspond to systematic limitations in that kind of argument.
Of course, even when there appears good reason for artificial intervention based on the above criteria there may still be good reason to exercise caution. If we don’t have a complete topology of the evolutionary factors at play then maybe nature does know best until we do. Nonetheless, technology is increasingly providing us with greater creative and destructive power and how we use it is up to us. For the first time in evolutionary history we stand at a juncture where our species can choose its own nature and future, an enterprise best undertaken without recourse to superstition or the whims of intuition. Like any tool, technology can be misused; a hammer can be used to commit a murder or build a house. How we use these tools is up to us.
Bostrom, N., & Sandberg, A. (2009). The wisdom of nature: an evolutionary heuristic for human enhancement. Human enhancement, 375-416.