Scientists discussed new approaches to understanding how life began, at a European Science Foundation (ESF) and COST Frontiers of Science conference in Sicily in October.
They discussed applying complex systems theory to the chemistry that preceded early life, as well as studying Mars, which may indicate what Earth was like when life evolved.
Complex systems chemistry uses computer models to simulate combinations of reactions involving membrane forming reactions, self-replicating nucleic acids and metabolic energy-producing reactions.
It then examines how these systems develop in time and space.
Gunter Von Kiedrowski, from Ruhr Universitat Bochum in Germany, described its science, which takes the opposite approach to that of genomics pioneer Craig Venter, who wants to build a minimal living cell.
Von Kiedrowski said: 'Venter wants to see what is left if you knock out everything but what is needed to survive.
'We want to look at how you get to that from the bottom up.
'Darwin's tree of life must have roots and it is our mission to find them.' One promising area of complex systems chemistry is the discovery of reaction systems that lead to the spontaneous generation of chiral asymmetry.
It is a universal property of life that compounds such as amino acids and sugars exist exclusively in a one-handed form, although both forms are equally likely from an energetic point of view.
It is quite difficult to achieve this asymmetry in non-living chemical reactions.
Chemistry tends to create equal proportions of the different forms, which behave like objects and their mirror images.
Von Kiedrowski added: 'The recipe for asymmetry is the co-occurrence of positive and negative feedback loops within such systems.' Complex systems chemistry cannot tell the story of life entirely.
Von Kiedrowski added: 'We are in the same position as the physicists trying to understand the origin of the universe.
'We will not know exactly how life began, because we do not know the precise conditions at the time, but we can get a good model of how it could have happened with this approach.' Understanding the context of early life from the evidence on Earth is difficult.
Because the Earth's crust is so active, there is little surface rock remaining from the time when life originated more than 3.5 billion years ago.
Tanja Zegers, a geoscientist from Utrecht University in the Netherlands, said: 'There are only two places on Earth where rocks formed at that time are relatively well preserved.' These are at Pilbara in Australia and Kaapvaal in South Africa.
The pillow basalts at Pilbara provide strong evidence that there was liquid water on Earth at that time, because their shape could only have developed underwater.
Liquid water is crucial for life.
But Zegers says understanding the origin of life from this evidence is like trying to piece together western civilisation from Asterix and Obelix cartoons.
On Mars though, about 50 per cent of the surface is more than 3.7 billion years old, so there is more to work with.
Zegers said: 'Mars may be our best bet to find out about life's origins on Earth.' At the time life was evolving on Earth, there was liquid water on Mars as well and a similar environment.
The oldest areas on Mars have hydrated minerals, such as clays, which contain water within the mineral structure.
They also show signs of surface flows like river networks.
But about 3.8 billion years ago, Mars's atmosphere declined and the planet went into a deep freeze.
Now, atmospheric pressure on Mars is too low for water to exist as a liquid.
Understanding habitability on Mars and early Earth requires focused geological research.
The European Space Agency (ESA) and NASA have planned several missions to Mars in the coming years to map the planet and eventually bring back samples.
But Zegers argues that in Europe, Mars research is not well co-ordinated.
There is no organisation responsible for managing and disseminating the scientific and survey data resulting from European Mars-missions and the scientific community using the data is not fully involved in the early stages of mission-planning.
Zegers said: 'We need a European programme for missions to Mars and a European planetary information programme.' This research was presented at the 'Complex Systems: Water and Life' Frontiers of Science conference, organised by European Science Foundation and COST on 29-31 October in Taormina, Sicily.
