The Battle Of The Sexes

By , 17 December 2014

The Battle Of The Sexes
The Battle Of The Sexes

Once upon a time eggs and sperm where the same size. Or more correctly, once upon a time there were no eggs and no sperm. Just gametes. Equal in size and equal in cost these gametes could reproduce with each other in a happy and fair trade.

Then one day an individual chanced upon a mutation that would change the world forever. His small, undersized gametes gave him a reproductive advantage, allowing him to have more offspring at a lower cost. He was the first male.

His family flourished with the advantage of cheap sex and further mutations drove his gametes smaller and smaller - until one day something unexpected happened: His family could no longer reproduce successfully. Their gametes were too small to create viable offspring.

Meanwhile, on the other side of the pond lived another individual who acquired a mutation that led to large gametes. Costly and burdensome her large gametes were a reproductive disadvantage. Her family was small and struggling. She was the first female.

The Battle Of The Sexes

She spend so much energy producing her gametes there was little energy left for her family to flourish - until one day something unexpected happened: her oversized gametes met huge demand. The males with their hugely successful small sperm had evolved themselves into a corner. It still took the same amount of energy to create offspring, and the only way now for them to meet these energy requirements was to mate with the family on the other side of pond. The females.

As the demand for her eggs skyrocketed her family flourished. Spending their energy only in making big eggs assured her family's reproductive success as long there continued to be a plentiful supply of sperm seeking out her out gametes - and there was.

Except now she was faced with a new problem. To mate within her only family became impossible. Over time her gametes had grown so large and cumbersome they could not fuse with each other. She had no choice but to mate with the males, whose small gametes she could easily attract and consume to create a genetically viable individual. However being in the position of greater demand also meant she could be selective, demanding high investment from the males even as they sought to invest as little as possible.

For 600 million years males continued their relentless pursuit of cheap sex, driving their gametes smaller and smaller while forcing females to produce larger and larger eggs. Females retaliated by demanding more and more male investment in some species even eating him alive after (or during) sex.

... and so continues The Battle of the Sexes.

About Roger Keays

The Battle Of The Sexes

Roger Keays is an artist, an engineer, and a student of life. He has no fixed address and has left footprints on 40-something different countries around the world. Roger is addicted to surfing. His other interests are music, psychology, languages, the proper use of semicolons, and finding good food.

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