The human embryo is destined to become female by default unless several chemicals swing into action.
The word sex comes from the Latin secare which means to separate or divide.
What most people do not know or appreciate is how the body decides whether to make male or female parts.
The kidney may not be as sophisticated as the brain or the liver, but it definitely has a lot of roles to play.
By using Tim’s case, we will see what would have happened to our earliest ancestors without any one of them.