The origin of life and its existence elsewhere than on planet Earth

Studies of the origins of life are closely interwoven with exobiology (Raulin-Cerceau et al., 1998). It is highly probable that the full range of conditions present on Earth since its formation are present elsewhere. On a virtual trip through the Universe, we would travel not only in space, but also back in time into the Earth's biological history. The search for past, dormant or currently existing extraterrestrial life is one of the most thought-provoking challenges for biology. It is based on the certainty that liquid water and other key chemical and physical environmental conditions for the development of living organisms, as we know them, were, or are, present elsewhere in the Universe than on our planet. Any evidence of extraterrestrial life, from Mars sample analysis for example, would be of major interest for all biology. It would contribute to an understanding not only of the definition and origin of life, but also of the evolution and adaptation of molecular mechanisms in living cells, or of how organisms adapt and develop within ecosystems.

Why study life in extreme environments?

Life on Earth is almost everywhere! And because it is almost everwhere around us, we can hope to define the extreme limits for its existence by studying it here on Earth.