For a detailed description of this idea, see my mind rambling topic Synthesized voices . We won't be able to create truly virtual characters without allowing them to move freely however. Creating smooth motions of the wide variety that living creatures like humans and animals use is exceedingly difficult. In the past this has been accomplished by painstakingly moving the skeleton of a virtual character's model in such a way as to appear as smooth as possible. Doing this requires tremendous skill and practice and has moderate results.
Motion capture seems like a godsend of a solution.
By capturing the motions of real people and animals we can animate virtual characters with perfectly natural motions. The problem is that this requires a real physical person or animal to perform every necessary motion so that it can be recorded. What I propose is that we use motion capture to define the fitness function for a genetic algorithm. This genetic algorithm will evolve virtual characters that know how to move in fluidic natural ways. These virtual characters' motions will evolve to match the motions of motion-captured real people and animals.