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The theory of evolution provides a clear, demonstrable mechanism for development and diversification of life, for the origination of new species and an explanation of the multitudes of shapes and sizes of living things. New ideas and insights are formed and the theory is built on incrementally with new information, but the underlying principle has remained solid. It is a fact that evolution happens - how and why it happens we can, and will, still learn much more about.

What remains the big question for science - and where those of a religious nature may still look for the hand of a god - is the very origin of life on Earth in the first instance. At what stage can something be called 'living'? It's not an easy question, really. We're comfortable with thinking of single-celled forms as living - though it's not much of a life - but at what point does chemistry become biology? Genetic replication? It's a field of science that sees a great deal of research, naturally, and there are a number of lines of thinking - hypotheses with evidential support which should eventually produce a single dominant theory. This, in turn, will gradually gain acceptance outwith the scientific world and act as a platform for further research. It takes a while for an idea to be suggested, tested, embraced, reach the textbooks and become... general knowledge.

At the moment, areas of work that may provide a solution include oceanic hydrothermal vents (black smokers), ribonucleaic acid (RNA) storing information and developing to DNA, and iron and sulphur layers in areas of volcanism. Another possibility suggested is that material from elsewhere provided the initial source material for life on Earth. Of course, that doesn't solve the problem of the origins of life, merely shifts it elsewhere, but it could deliver an answer to what happened on our planet. Meteorites found in Sudan in 2008 contain amino acids, and other examples with these proto-proteins have been found in the past. It does seem very possible we may all be aliens.