Two Approaches to the Study of the Origin of Life

Abstract

This paper compares two approaches that attempt to explain the origin of life, or biogenesis. The more established approach is one based on chemical principles, whereas a new, yet not widely known approach begins from a physical perspective. According to the first approach, life would have begun with-often organic-compounds. After having developed to a certain level of complexity and mutual dependence within a non-compartmentalised organic soup, they would have assembled into a functioning cell. In contrast, the second, physical type of approach has life developing within tiny compartments from the beginning. It emphasises the importance of redox reactions between inorganic elements and compounds found on two sides of a compartmental boundary. Without this boundary, ''life'' would not have begun, nor have been maintained; this boundary-and the complex cell membrane that evolved from it-forms the essence of life.

Geological evolution of the marine selenium cycle: Insights from the bulk shale δ82/76Se record and isotope mass balance modeling

“…The perturbations imposed on the model are designed to assess the sensitivity of marine Se isotope systematics to large departures from baseline Se cycling in the modern ocean. Using the same model across geological time assumes that assimilatory uptake of Se was an important biochemical pathway throughout, and that Se was incorporated into the biochemistry of cells during the emergence and evolution of life, possibly even before S (Hengeveld, 2007;Hengeveld and Fedonkin, 2007;Rao et al, 2003;Romero et al, 2005;Sun and Caetano-Anollés, 2009). Because the modern Se cycle is dominated by assimilatory reduction and oxidative recycling of DISe, we focus on perturbations where (1) assimilatory DISe uptake in the surface waters is decreased (Perturbation 1), (2) oxidative recycling in the water column and sediments is inhibited (Perturbation 2), (3) dissimilatory Se reduction is increased (Perturbation 3), and (4) the previous perturbations are combined (Perturbation 4 = Perturbations 1 + 2 + 3, Perturbation 5 = Perturbations 1 + 2).…”

Definitions of Life are not Only Unnecessary, but they can do Harm to Understanding

“…This puts the problem within the thermodynamic realm. A basic requirement, one that can be met by several properties, therefore differs from a property, physical, chemical, biological, or socio-economic; instead, it defines both the process and the shape of molecules taking part in it (Hengeveld 2007). It defines the properties.…”

Functional Genomics of Anoxygenic Green Bacteria Chloroflexi Species and Evolution of Photosynthesis

“…Various perspectives on evolution of photosynthesis have been reported in literature [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25], whereas our understanding of transition from anaerobic to aerobic world is still fragmentary. The recent genomic report on Cfl.…”