The chicken or the egg? Sometimes, as a zoology author, I am asked this question by the kid at the front with the raised hand and large questioning eyes. Sometimes it’s the older guy at the back with a glint in his eye. Sometimes it’s a student who approaches the lectern at the end of a lecture while everyone else files out. The same mischievous eyes, the same wry smile. “So which came first?” they ask, beaming, unaware that this is not the first time I have been asked.
I hadn’t foreseen, years ago, when I began exploring the evolution of the animal egg and the role it has played in the long history of life on this planet, that it would become pretty much the only question I would be asked. I spent years reframing the evolution of life on Earth as a story told from the egg’s perspective, tracing this strange vessel’s adaptation to land, its movement across continents, the evolution of the umbilical cord, the evolution of the placenta, menstruation, menopause… but even now, having finally turned this journey into a book, I expect that a great deal of my dialogue with readers will be chicken-based.
