On the other hand, the genes that encode for temperature and pressure tolerance have much more complicated systems and are a part of the single, primary DNA strand in a given organism. The temperature and pressure tolerance systems are made up of a large number genes that perform a variety of functions to stabilize a cell's proteins under stressful conditions, for example. It would be incredibly difficult to move all the necessary information between cells. Don't sell your stock in autoclave companies yet. You're totally right.
Chemosynthetic ecosystems make a great model for extraterrestrial life.
As long as there is liquid water and hydrothermal activity, there is the possibility of chemosynthetic life. Planetary geologists and astrobiologists are looking to places like Europa, one of Jupiter's moons, as likely spots for extraterrestrial life, because the necessary life-sustaining conditions may be there. The chemosynthetic vent system has many primary producers. Some microbes can eat hydrogen and carbon dioxide to survive, and this mode of life is quite conceivable on Europa. Others eat hydrogen sulfide and oxygen.