In reply to es:
The places in the team are decided on form throughout the year based on UK competitions and competitions abroad. Members who are already in the team are also assessed on their commitment to the team in terms of training and how they've performed in the team training sessions throughout the year.
Regarding the females, myself and Fliss Butler decided that there wasn't a high enough "absolute" level of performance this year amongst those interested, so only 2 were selected. Last year, it was 50:50 purely by chance and in previous years there have been no women at all!
For more info have a look at the British Team Website and the corresponding BMC section.