The idea of having three parents seems ripe to provoke both stand-up comedy routines and horror. It arises from the latest developments in reproductive technology, developed at Newcastle University, that would create embryos with DNA that is not wholly from the mother and father.
The third “parent” is an egg donor. The egg will be stripped of its nucleus, where the chromosomes reside, and replaced with that from a normal IVF embryo, containing maternal and paternal genes. But the egg will retain a few donor genes, 37 to be precise, in energy-generating compartments outside the cell nucleus, called mitochondria. This would eliminate diseases caused by faulty mitochondria in the mother’s eggs.
All the genes that influence the child’s development would be those of the mother and father — except for the handful that operate “out of sight” to drive the mitochondria. Strictly speaking this does make the egg donor a kind of genetic parent — but the better analogy is with transplant patients, who, rather than having a tiny bit of “foreign” genetic material in every tissue, have entirely foreign genes in one particular tissue.
So any talk of a “third parent” plays up the alleged weirdness of the situation, not least by introducing an exciting whiff of sexual irregularity. And by making parental status one of genetic entitlement rather than responsibility of care, it plays along with the current notion of “Genes’R’Us”. Objections such as that put by the charity Life that the work raises questions of who is the real mother seem to place an extraordinary burden of identity on those 37 genes.
We are reaping the harvest of modern genetics, especially projects to read the chemical code of human genomes. In their determination to sell this undoubtedly valuable enterprise, genetic scientists have all too often opted to present the genome as the “book of life” or, as one scientist put it, “the set of instructions to make a human being”.
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Such claims encourage us to equate our being with our genes to an unsupportable degree. In fact, genes may be silenced, ignored or modified by environmental factors encountered by the developing organism. Any “identical” twin (a revealing term in itself) will tell you that personal identity is not the same as genetic endowment. But the myth of genetic determinism is falsified beyond even these things. As the physiologist Denis Noble has elegantly argued, genes are “instructions” in roughly the same way that Bach’s scores, free of dynamics and ornaments, are prescriptions for music that brings tears to the eyes. (Even that is too tight an analogy, unless the performance admits improvisation.) Genes work not because they specify everything but precisely because there is so much that they do not need to specify.
If we had a better understanding of genetics — I don’t just mean the public, but scientists too — we would be less likely to indulge in a gene-based, materialistic view of parenthood and identity, and to confuse our bodies with our genomes. The “yuk factor” response to embryos with non-maternal mitochondrial genes is a form of genetic narcissism. After all, most of the cells in our bodies are not human but symbiotic bacteria in our gut, busy performing a host of functions on which our wellbeing depends. In any case, our genomes are patchworks of genes that no one can meaningfully claim as “their own”. In genetic terms we are all Frankenstein’s creatures. Whether we have a single parent or three, we just have to hope they do a better job than Victor did.
Behind all this, however, is the deeper current of attitudes to “unnatural” interventions in procreation. Here we swim in the murky waters of myth. When scientists in 2009 announced in Nature that they had achieved these “mitochondrial transplants” in monkeys, an editorial acknowledged that “[an] argument raised when such research has been attempted in the past is that such a three-parent union is ‘unnatural’.” One obvious rejoinder is to point to the neonatal infant mortality rate two centuries ago when birth involved very little intervention, so was more “natural”. But the function of the word “unnatural” here is not merely to point out that these things don’t happen in nature, but to enlist moral disapproval. The unnatural act is not just the opposite of the natural, but one we are invited to deplore.
Even if we substitute instead the word “artificial”, the implication remains. This is an ancient prejudice. The distinctions and relative merits of “art” (meaning artifice) and “nature” were debated by Plato and Aristotle, and it was not until the 17th century that there was any serious challenge to the view that artificial objects cannot be equal to natural ones. Often this prejudice went beyond the assertion that the products of technology are inferior: there was a suggestion that technology is inherently perverting.
The biologist J. B. S. Haldane put it this way in 1924: “If every physical and chemical invention is a blasphemy, every biological invention is a perversion. There is hardly one which, on first being brought to the notice of an observer ... would not appear to him as indecent and unnatural” Five decades later, IVF proved his point again. It is still opposed in the Roman Catholic catechism, which complains of “the domination of technology over the origin and destiny of the human person”. Far from enabling the birth of a longed-for child, for the Church this technology creates an indelible stain on the “origin and destiny” of any person in whose conception it is involved.
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None of this is to deny that the work being contemplated at Newcastle needs careful consideration of ethics as well as safety. But presenting the issues in terms of a confusion of parenthood illustrates that we are trying to make sense of biomedical developments by using moral and social contexts that they have already left behind. In an age of advanced prosthetics and transplantation, tissue engineering and rapid genomic profiling, we must escape from the tendency to shoehorn our uniqueness into a molecular structure and look for it instead in how we inhabit the world.
Philip Ball is the author of Unnatural: The Heretical Idea of Making People