5 research outputs found
A Strategy for Origins of Life Research
Aworkshop was held August 26–28, 2015, by the Earth-
Life Science Institute (ELSI) Origins Network (EON,
see Appendix I) at the Tokyo Institute of Technology. This
meeting gathered a diverse group of around 40 scholars researching
the origins of life (OoL) from various perspectives
with the intent to find common ground, identify key questions
and investigations for progress, and guide EON by suggesting
a roadmap of activities.
Specific challenges that the attendees were encouraged to
address included the following: What key questions, ideas,
and investigations should the OoL research community address
in the near and long term? How can this community
better organize itself and prioritize its efforts? What roles
can particular subfields play, and what can ELSI and EON
do to facilitate research progress? (See also Appendix II.)
The present document is a product of that workshop; a
white paper that serves as a record of the discussion that
took place and a guide and stimulus to the solution of the
most urgent and important issues in the study of the OoL.
This paper is not intended to be comprehensive or a balanced
representation of the opinions of the entire OoL research
community. It is intended to present a number of
important position statements that contain many aspirational
goals and suggestions as to how progress can be made in
understanding the OoL.
The key role played in the field by current societies and
recurring meetings over the past many decades is fully acknowledged,
including the International Society for the
Study of the Origin of Life (ISSOL) and its official journal
Origins of Life and Evolution of Biospheres, as well as the
International Society for Artificial Life (ISAL)
Determinism and Contingency Shape Metabolic Complementation in an Endosymbiotic Consortium
Bacterial endosymbionts and their insect hosts establish an intimate metabolic relationship. Bacteria offer a variety of essential nutrients to their hosts, whereas insect cells provide the necessary sources of matter and energy to their tiny metabolic allies. These nutritional complementations sustain themselves on a diversity of metabolite exchanges between the cell host and the reduced yet highly specialized bacterial metabolism-which, for instance, overproduces a small set of essential amino acids and vitamins. A well-known case of metabolic complementation is provided by the cedar aphid Cinara cedri that harbors two co-primary endosymbionts, Buchnera aphidicola BCc and Ca. Serratia symbiotica SCc, and in which some metabolic pathways are partitioned between different partners. Here we present a genome-scale metabolic network (GEM) for the bacterial consortium from the cedar aphid iBSCc. The analysis of this GEM allows us the confirmation of cases of metabolic complementation previously described by genome analysis (i.e., tryptophan and biotin biosynthesis) and the redefinition of an event of metabolic pathway sharing between the two endosymbionts, namely the biosynthesis of tetrahydrofolate. In silico knock-out experiments with iBSCc showed that the consortium metabolism is a highly integrated yet fragile network. We also have explored the evolutionary pathways leading to the emergence of metabolic complementation between reduced metabolisms starting from individual, complete networks. Our results suggest that, during the establishment of metabolic complementation in endosymbionts, adaptive evolution is significant in the case of tryptophan biosynthesis, whereas vitamin production pathways seem to adopt suboptimal solutions
Hidden Concepts in the History of Origins-of-Life Studies
In this review, we describe some of the central philosophical issues facing origins-of-life
research and provide a targeted history of the developments that have led to the multidisciplinary
field of origins-of-life studies. We outline these issues and developments to guide
researchers and students from all fields. With respect to philosophy, we provide brief summaries
of debates with respect to (1) definitions (or theories) of life, what life is and how research
should be conducted in the absence of an accepted theory of life, (2) the distinctions between
synthetic, historical, and universal projects in origins-of-life studies, issues with strategies for
inferring the origins of life, such as (3) the nature of the first living entities (the “bottom up”
approach) and (4) how to infer the nature of the last universal common ancestor (the “top
down” approach), and (5) the status of origins of life as a science. Each of these debates
influences the others. Although there are clusters of researchers that agree on some answers to
these issues, each of these debates is still open. With respect to history, we outline several
independent paths that have led to some of the approaches now prevalent in origins-of-life
studies. These include one path from early views of life through the scientific revolutions
brought about by Linnaeus (von Linn.), Wöhler, Miller, and others. In this approach, new
theories, tools, and evidence guide new thoughts about the nature of life and its origin.We also
describe another family of paths motivated by a” circularity” approach to life, which is guided
by such thinkers as Maturana & Varela, Gánti, Rosen, and others. These views echo ideas
developed by Kant and Aristotle, though they do so using modern science in ways that
produce exciting avenues of investigation. By exploring the history of these ideas, we can
see how many of the issues that currently interest us have been guided by the contexts in which
the ideas were developed. The disciplinary backgrounds of each of these scholars has
influenced the questions they sought to answer, the experiments they envisioned, and the
kinds of data they collected. We conclude by encouraging scientists and scholars in the
humanities and social sciences to explore ways in which they can interact to provide a deeper
understanding of the conceptual assumptions, structure, and history of origins-of-life research.
This may be useful to help frame future research agendas and bring awareness to the
multifaceted issues facing this challenging scientific question
Prebiotic Chemistry – Biochemistry – Emergence of Life (4.4–2 Ga)
This chapter is devoted to a discussion about the difficulties and even the impossibility to date the events that occurred during the transition from non-living matter to the first living cells. Nevertheless, the attempts to devise plausible scenarios accounting for the emergence of the main molecular devices and processes found in biology are presented including the role of nucleotides at early stages (RNA world). On the other hand, hypotheses on the development of early metabolisms, compartments and genetic encoding are also discussed in relation with their role in extant living organisms. The nature of the Last Common Ancestor is also presented as well as hypotheses on the evolution of viruses. The following sections constitute a collection of independent articles providing a general overview of these aspects. © Springer Science+Business Media B.V. 2006.SCOPUS: ar.jinfo:eu-repo/semantics/publishe