EARTH SCIENCE

Viewpoint: Yes, the theory that life began in the "little warm pond" has supporting evidence from a number of experiments, and competing theories are more problematic.

Viewpoint: No, either life began on the surface during the period known as the late heavy bombardment, or it began in a protected environment away from the surface and the devastating impacts.

The origin of life on Earth is one of the most important, and elusive, problems in science. Efforts to understand the origin of life have been frustrated by lack of evidence. In the face of this fundamental difficulty, the search for a scientific explanation for the origin of life has relied upon speculative hypotheses, observations from present conditions on Earth and elsewhere in our solar system...