Here is a picture of a very modern family: Alan and Brenda would like to raise a child but both are incapable of natural reproduction. So they find Carl to provide sperm, Deena to provide an egg, and Ellen to carry the fertilized egg in her uterus. Nine months later, Alan and Brenda are the child’s nurturing parents, Carl and Deena are the biological parents, and Ellen is the birth mother. Five parents, one child.
While this parenting pattern is unusual, we have made children this way for decades. Parenting may soon get even more complicated. Researchers from the Oregon National Primate Research Center recently created several macaque monkeys each of which has three biological parents.
Most of our genetic code is determined by the chromosomes in a father’s sperm and a mother’s egg. We also have a small amount of DNA that comes not from chromosomes but from the mitochondria in our mother’s egg. The recently-created macaques received chromosomal DNA from one mother and mitochondrial DNA from another mother. The macaques were born with DNA from three parents in total.
The research has been heralded as a potential method for mothers with mitochondrial genetic disorders to have biological children. If the method works in humans, a woman with genetically-diseased mitochondrial DNA could find a mitochondrial-DNA donor. At least in theory (there'd be no practical reason for doing it this way), we could add one more parent to the modern family described above. Six parents, one child.
The implications of the research go further still. For if we get good enough at engineering germline DNA, we could use genetic contributions from lots of people to make children who are free from genetic diseases or have particular attributes. Each parent would provide just a small part of the child's genetic code. One hundred parents, one child.
In a variety of contexts, courts give special weight to the interests of biological parents. We have enough trouble deciding custody cases in traditional families, and the issues would obviously get more complicated when children have more than two biological parents. For example, mitochondrial DNA is passed along from mother to child and stays relatively unchanged each generation. The information in your mitochondrial DNA is as much your grandmother’s as your mother’s. If biological parenthood is determined by the information in our genetic code, the difference between parents and grandparents starts to evaporate.
If we project our technological abilities even further, we will eventually be able to insert artificially-crafted strands of DNA into a human germline. Just as a child can be nurtured by any number of people, a child can, in principle, be biologically parented by any number of people. Once we have the pertinent information that we want to put in a child's DNA, we will no longer need a physical specimen of parents' DNA at all. No parents, one child.
While we are used to living in a world with difficult custody battles, we at least thought we knew what it meant to be a biological parent. In the not-too-distant future, even that category will grow fuzzy. Parenthood, in all its forms, is increasingly just a matter of degree.
(This post appeared originally on Prawfsblawg.)
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