The reason for differenciated sex-bearers

Well then. I always thought that I would want to write one day.

Here's my chance. Thing is, you got to have tell a story or say something somehow interesting.

OK, here is an idea : I should log all thoughts that I deem interesting to record for personal use.

Example : this is a question : why does mankind have sex ? The answer is not so obvious.
First element : sex is more efficient to exchange genes for big and slow reproducing animals.
But there is still the possibility of being hermaphrodite ! According to some letter written by a
reader of "The New Scientist", there is a 2-fold cost of being dioecious - ok, but what is the
advantage ??