Human beings are evolved organisms, whose traits have been optimized by a process lasting millions of years. Attempts to enhance such systems undertaken with imperfect understanding of their inner workings are likely to backfire. This insight may be expressed as an evolutionary optimality challenge (Bostrom & Sandberg 2009: 378):
If the proposed intervention would result in an enhancement, why have we not already evolved to be that way?
The evolution heuristic holds that a failure to provide an answer to that question creates a presumption against the proposed intervention. But the heuristic also identifies three types of considerations that could answer the question, and hence defeat the presumption (Bostrom & Sandberg 2009: 378–380):
Bostrom, Nick & Anders Sandberg (2009) The wisdom of nature: an evolutionary heuristic for human enhancement, in Julian Savulescu & Nick Bostrom (eds.) Human Enhancement, Oxford: Oxford University Press, pp. 375–416.
The evolution heuristic (sometimes referred to as the wisdom of nature) is a heuristic for evaluating possible forms of cognitive enhancement. The heuristic was proposed by Nick Bostrom and Anders Sandberg in a 2009 paper (Bostrom & Sandberg 2009).