  We discuss the difficulties of forming earth-like planets in metal-poor
environments, such as those prevailing in the Galactic halo (Pop II), the
Magellanic Clouds, and the early universe. We suggest that, with less heavy
elements available, terrestrial planets will be smaller size and lower mass
than in our solar system (solar metallicity). Such planets may not be able to
sustain life as we know it. Therefore, the chances of very old lifeforms in the
universe are slim, and a threshold metallicty (1/2 solar?) may exist for life
to originate on large enough earth-like planets.
