The year 2015 has been a decisive year for the future of mitochondrial replacement therapy – at least in the Western world. Currently, the UK and the US governments are undergoing a process of ethical and scientific evaluation of the technique to decide whether to allow its implementation or not. MRT requires the fusion of the DNA of three parents into an embryo – and this creates a number of worries as to what this scientific innovation will lead to. These (...) worries might be well placed and worthy of consideration, but not on the grounds presented by some opponents. In this paper, we will analyse a recent European Union petition that urged the UK government to refrain from legalising MRT, stressing that other techniques, such as preimplantation genetic diagnosis, already have a more direct eugenic potential than MRT. Although the UK Parliament recently voted in favour of MRT, an analysis of the EU petition can nonetheless still contribute to understanding some of the key aspects of the debate. Our conclusion is that what seems to be really at stake, instead, is whether or not we are willing to reconceptualise our notion of parenthood as something not necessarily binominal and genetically related. (shrink)