Alice's confusion brings to mind Nature's dance of unexpected twists and turns which may, or may not, provide favourable conditions for achieving reproductive success. The twists and turns are not automatically in synchrony with species’ requirements to persist through time. All life forms compete to maximize their reproductive success by counterbalancing conflicting interests and calculating cost and benefit analyses. Humans, and their Quaternary companions in evolution, exist today only because they are the descendants of those that successfully reproduced in past environments. Future generations, if they are to survive, will need to do the same and adapt to rapidly changing environmental conditions – not an easy ask.

The foundation of normal adult reproduction is set during fetal life. Sex, as all other functions, is the product of dancing genetic and epigenetic variables so complex that under normal conditions developmental instructions seem to appear from one adaptable informational unit. While genetics focuses on how organisms retain traits by inheriting genes from their parents, epigenetics refers to additional methods of biological inheritance that do not directly relate to the inheritance of collections of genes.