This article contains my personal opinions and musings.
Today is the start of the London 2012 Summer Olympics. This year’s olympics has faced a number of controversies – one of which is somewhat pertinent to biology, the issue of gender and sex. The olympics, like many sporting institutions, has long separated competitors into two main categories – male and female. This would be simple, if sex determination was so discrete. But sex is not discrete, it is a spectrum which at best can be described as two common clusters of phenotypes around what we call ‘male’ and ‘female’. Even chromosomal sex is not as simple as XX vs XY – there are common cases of XXY and XYY and other varieties. Genitals don’t always follow the chromosomal pattern either, and hormone diversity (which drives development) creates an effective continuum between male and female. Individuals significantly between both sexes are often referred to as “intersex” but even then the line between intersex and being one sex or another is a blurred one.