The papers in this collection record the talks given at the conference on “Open Questions on the Origin of Life” held in Leicester in May 2012. This was the third such meeting in a series inspired by Professor Luisi with the agenda to discuss open problems and new approaches. The format of the papers presented here broadly keeps to that of the conference, with the extended abstracts of the talks followed by comments from other delegates, which capture just some of the lively discussions.

Prior to the meeting the community is asked to submit questions for each of the conference sessions which are then chosen by ballot. In fact, the main characteristic of this kind of meeting is to collect those questions in the field of the origin of life which are not yet answered. Thus, while most of the conventional science meetings emphasize the new achievements, and ignore the points of ignorance, our meeting dwells precisely on the” dark side”, more in particular on the reasons why certain questions remain unsolved, and occasionally even ignored in the scientific discussion—and we try to understand why this is so, possibly looking for ways to come out of the impasse.

This is not the place to summarise the individual questions or contributions but some of what seemed to me to be key themes did emerge. The largest group of contributions were identified by their authors as concerning the transition from chemistry to biology, perhaps because this can be interpreted as simply another way of posing the origin-of-life question in general terms, which is not quite the intention of these meeting. But one specific issue is whether we need new conceptual frameworks to address this, or if the established frameworks of chemical kinetics and Darwinian evolution can be made to join up. Darwinian evolution is not confined to a biological substratum, but works as a general framework (for example in the use of genetic algorithms in engineering). Clearly, however, Darwinian evolution does not take us from molecules to organisms in a single step, but through a hierarchy of emergence. The origin-of-life problem asks for the articulation of the series of phase changes in between. Which one of these changes is THE origin of life seems to us to be of less interest. The real problem is the difficulty of constructing the missing phases, and, in particular, what evidence would demonstrate that we had succeeded. Presumably the only way to find out is to start at both ends: from molecular chemistry (both theoretical – witness the discussion on multi-copies - and experimental) and genetic analysis (for example, the evidence that metal complexes give clues to the location of the first life), pushing both as far as possible in the hope that they meet.

While the RNA world adherents were represented, alternative or complementary approaches were more in evidence, particularly in relation to vesicle formation (prebiotic chemistry) and evolution, particularly encapsulation. Perhaps here too we have to push each approach as far as possible in the hope that they too will meet at a future conference.

In the view of one of our delegates (RW) one of the main problems that the recent meeting highlighted is the general lack of a standard, technical vocabulary which could be used by origin-of-life researchers. For example, some of us used terms like self-assembly and self-organization as synonymous, while others used these same terms to describe quite different processes. Many researchers use terms such as self-replication and self-reproduction interchangeably, whereas some of us look for fine differences between them, applying the first term to sequences of genetic

information and the second to larger physical assemblies like cells or vesicles. In this recent meeting, in one of the first talks, the term “self-maintenance” was used synonymously with “self-production” and in one of the last talks the same terms where used to differentiate between life (possessing both of those qualities) and other dissipative structures (possessing only the first one).

Clearly, if we use the same words but mean different things we cannot know whether our disagreements are real or just misunderstandings. Many other terms came up during our discussions: steady state, kinetic trap, energy flow, Darwinian evolution. All of these have precise meanings in other fields, but sometimes they possess different meaning in different fields. When we import them to our field we should be sure that we mean the same thing: our discussions seemed to show that often we do not. Also when we abandon terms for others coined by ourselves we should be able to explain such a choice rationally, which again requires that we start from a common understanding of those terms.

Several young scientists present at the meeting experienced for the first time this climate of discussion and the recognition that we do not have all answers yet: and they responded with enthusiasm. Another unique characteristic of the meeting is the attempt to integrate contributions on the philosophy of science, an important consideration if we wish to understand the basis of our research. We would like to conclude by saying that this kind of meeting, where the formal sessions are largely given over to debate that which is not understood and, more particularly why, represents a very honest contribution to the field, and this is an initiative that should be continued…