Star Trek: 10 Crazy Facts About The Trill
3. The Lie Of Exclusivity
It was the job of the Symbiosis Commission to regulate the process of selecting new hosts for symbiosis. Not every Trill was suitable for the joining process. Tens of thousands of applicants would apply every year but only 500 symbionts were available, either through the death of the current host or the birth of a new symbiont.
Simply put, there wasn't enough supply to meet the demand. So the Symbiosis Commission maintained massive lie.
The long-standing claim was that only a very small percentage of Trills were suitable for the joining process. As such, the Commission had to carefully vet all applicants to make sure that they would be a good fit for the symbionts. In reality, the number of Trills suitable for joining was closer to 50%.
Symbiosis Commission told and maintained the lie to control the expectations of the Trill population. By making the process seem more exclusive, the Commission prevented too many Trills from depleting the numbers of symbionts available.
The truth was discovered when the Dax symbiont had a problem that could only be solved on Trill. It was revealed that Dax had a secret host who turned out to be an evil murderer. This would have proven that anyone could be a host, which is the last thing the Commission wanted.