21.   For that primitive life to evolve to higher forms may depend on how severely the planet is scoured by colliding asteroids and comets, experts believe.

22.   Talk about happy campers, a group of lifestyle researchers are moving back to the Iron Age to see what primitive life was all about.

23.   The long-term effect of electricity on their primitive life is still unclear.

24.   Earlier this week scientists at the US space agency NASA announced they had found evidence of primitive life on Mars.