The beautiful science of embryology

It’s a familiar story: the virile sperm fights its path through the hostile uterus to the passive female egg. After fertilisation, the resulting ball of cells is “totipotent,” with each unit equally capable of becoming any cell type in the placenta or foetus. Magdalena Zernicka-Goetz, an embryologist from the University of Cambridge, affronted her field by claiming this was wrong: not just the sexist metaphors, but also the assumption that the first human cells are identical. Her experiments showed that cells lean towards a particular fate, and that an embryo’s symmetry is broken from its earliest moments.

Together with science journalist Roger Highfield, Zernicka-Goetz leads us through the intricacies of modern embryology and reproductive technology. Her successes include doubling the length of time embryos can survive in the lab, building simulation mouse embryos out of stem cells and using fluorescent labels to make “embryo art.” “We are entering a new era,” she writes, “one where we can manipulate the cellular units of life as skilfully as a potter works clay.” While gene editing and designer babies raise understandable alarm, artistry...