There are some things in life where women have it better. We live longer, we have higher self-reported happiness and we are always certain of the biological relatedness between our babies and ourselves. Men can never be completely certain of their paternity since fertilization takes place internally. Given that cuckoldry has large fitness costs, it is not surprising that evolution has created psychological mechanisms in men that work to prevent this from happening (e.g. sexual jealousy). Likewise, it is not surprising that women assure men of their paternity by telling them that their newborn baby looks just like them—even when it more closely resembles the alien in the latest sci-fi movie.
This week biological parenthood became more complicated for both sexes when scientists from the Oregon Health & Science University created an embryo using DNA from two women and one man. The technique transferred chromosomes from one woman’s egg to a donor’s egg whose nucleus had been removed, but the mitochondria remained. This is good news for women who have mutations in their mitochondria and want to have children without the risk of their babies inheriting the defects. However, it has raised a number of thought-provoking questions. Can a child have more than two biological parents? Are certain amounts or types of genetic material needed to qualify someone as a biological parent?