Seeing as thought is still non-existent in a lot of the human population, I can believe that.

Come on BBC, this is a hypothesis, not a theory.

He told BBC News that, if his theory is correct, these life forms would have been similar to slime mould - a brainless single-cell organism that reproduces with spores.

Still a one cell organism. Even much of the less complex life forms have very much more cells.