Origin of evolution versus origin of life: a shift of paradigm - PubMed (original) (raw)

Origin of evolution versus origin of life: a shift of paradigm

Marc Tessera. Int J Mol Sci. 2011.

Abstract

The question of the primordial ancestor must be approached through the search for the origin of evolution, not through the search for the origin of life. There is a major issue with the concept of life because it is impossible to define, thus is not a scientific but a metaphysical concept. On the contrary, evolution may be defined by as few as three conditions. These do not necessarily involve biopolymers. However, such an approach must give clues to explain the emergence of distinct lineages to allow Darwinian natural selection. A plausible solution exists within an autotrophic lipidic vesicle-based model that is presented. The model requires the existence of hydrothermal sites such as the Lost City Hydrothermal Field leading to specific constraints. For this reason Mars and Europa may be questioned as possible cradles of evolution. If we replace the search for the origin of life by the one for the origin of evolution our priority first is to find a consensus on the minimal conditions that would allow evolution to emerge and persist anywhere in the universe.

Keywords: heredity; hydrothermal vents; lipidic vesicles; open far-from-equilibrium systems; origin of evolution; origin of life.

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Figures

Figure 1

Figure 1

Schematic representation of the catalyzing effect of a La local arrangement of the membrane with 3 simple single-chain surfactants with different single chain lengths (Aa, Ba: small molecules can pass through the vesicle membrane; Ca: substance synthesized from Aa and Ba, trapped in the vesicle); Ra, Rb: possibly variable chemical radicals that do not interact with La.

Figure 2

Figure 2

Schematic representation of the effect of Ca compound: stabilization of the La local arrangement into a stabilized Sa site.

Figure 3

Figure 3

Schematic representation of the catalysis of a new molecule Ca by the same Sa site (Aa, Ba: small molecules can pass through the vesicle membrane; Ca: substance synthesized from Aa and Ba, trapped in the vesicle); Ra, Rb: possibly variable chemical radicals that do not interact with the Sa site.

Figure 4

Figure 4

Schematic representation of the distribution of Sa sites on a local region of the inner surface of the vesicle membrane.

Figure 5

Figure 5

Schematic representation of the migration of Sa sites with the joining of two Sa sites.

Figure 6

Figure 6

Schematic representation of the catalysis of a di-Ca compound by two adjacent Sa sites: a Ca compound binds on each of the two adjacent Sa sites.

Figure 7

Figure 7

Schematic representation of the catalysis of a di-Ca compound by two adjacent Sa sites: synthesis of a di-Ca compound.

Figure 8

Figure 8

Schematic representation of the catalysis of the polymerization of Ca by a Sa-Sa site (here the synthesis of a tri-Ca): a di-Ca (in green) binds on the left Sa site of Sa-Sa while a Ca (in red) binds on the right Sa site.

Figure 9

Figure 9

Schematic representation of the polymerization of Ca by a Sa-Sa site (here the synthesis of a tri-Ca): a synthesized tri-Ca is released by the Sa-Sa site.

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