Martian theories

Yet again we hear that extra terrestrial life is more likely because some environmental factor or other has been discovered on another planet (your report, 17 June).

The underlying assumption that incredibly complex and sophisticated living organisms (and there are no other sort) might well pop into being if the right ingredients are present is just wild speculation.

Belief in the generation of life from non-living materials without intelligent structuring is based on philosophical dogma, not scientific discovery.

Scientists have not got a clue how life began on earth, so the suggestion that the presence of required chemicals makes it more likely to have begun elsewhere is unjustified. It’s about as sensible as saying that traces of iron on Mars make it more likely that there are or were cars on Mars.

Richard Lucas

Broomyknowe

Edinburgh