One of the most profound mysteries in the world, love between males and females, is explored. What was the evolutionary impetus which gave rise to love? Through an experiment involving the chlamydomonas, a green algae, we can see how genders first appeared 25 billion years ago. Mating can be a dangerous endeavour, with only the strongest winning the right to mate; from lady bugs to komodo dragons, mating rituals ensure continuation of the species.  The move from single celled self-replication to gendered mating has greatly increased the diversity of life.

In some species, gender shifting can occur when there are not enough males or females; some species are able to reproduce through parthenogenesis – offspring develop from unfertilized eggs.  Mammals give birth to live young and have developed ways of nurturing and protecting their babies.  The basic instinct of all living things is to produce offspring to continue the species.