How long can life forms stay active in a sealed glass sphere?

The answer turns out to not only be fascinating, but a nice little cottage industry. Ecosphere is a company that sells just such an item: a glass globe with simple plant and animal life forms, which you just set in the window and let sunlight do the rest. It's basically a sealed, maintenance-free aquarium.

Here's a video of one in action:

From the site:

"Because the living organisms within the EcoSphere utilize their resources without overpopulating or contaminating their environment, the EcoSphere requires virtually no maintenance.
EcoSpheres have an average life expectancy of two years. However, it is not uncommon for shrimp populations to be thriving in systems as old as 7 years."

One wonders what the long-term implications of this would be. What if generations reproduced within the ecosphere - would they mutate? Could they evolve? Certainly, sealed systems in nature do tend to produce life forms with exaggerated characteristics. Could the system survive a global apocalypse? It needs sunlight energy, so we know it couldn't survive in space, but what if we included an artificial life source and launched it at habitable planets? Would the seed be planted for Earth-like, but adapted, life forms when we eventually go there?