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Coupled phases and combinatorial selection in fluctuating hydrothermal pools: a scenario to guide experimental approaches to the origin of cellular life.

Damer B, Deamer D - Life (Basel) (2015)

Bottom Line: Two kinds of selective processes can then occur.The second is a chemical process in which rare combinations of encapsulated polymers form systems capable of capturing energy and nutrients to undergo growth by catalyzed polymerization.Given continued cycling over extended time spans, such combinatorial processes will give rise to molecular systems having the fundamental properties of life.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomolecular Engineering. bdamer@ucsc.edu.

ABSTRACT
Hydrothermal fields on the prebiotic Earth are candidate environments for biogenesis. We propose a model in which molecular systems driven by cycles of hydration and dehydration in such sites undergo chemical evolution in dehydrated films on mineral surfaces followed by encapsulation and combinatorial selection in a hydrated bulk phase. The dehydrated phase can consist of concentrated eutectic mixtures or multilamellar liquid crystalline matrices. Both conditions organize and concentrate potential monomers and thereby promote polymerization reactions that are driven by reduced water activity in the dehydrated phase. In the case of multilamellar lipid matrices, polymers that have been synthesized are captured in lipid vesicles upon rehydration to produce a variety of molecular systems. Each vesicle represents a protocell, an "experiment" in a natural version of combinatorial chemistry. Two kinds of selective processes can then occur. The first is a physical process in which relatively stable molecular systems will be preferentially selected. The second is a chemical process in which rare combinations of encapsulated polymers form systems capable of capturing energy and nutrients to undergo growth by catalyzed polymerization. Given continued cycling over extended time spans, such combinatorial processes will give rise to molecular systems having the fundamental properties of life.

No MeSH data available.


Related in: MedlinePlus

Computer generated conceptual view of a volcanic island rising above the global early Archaean ocean. Precipitation produces small hydrothermal pools that undergo cycles of evaporation and refilling (hydrothermal field and geyser shown at center of island).
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life-05-00872-f001: Computer generated conceptual view of a volcanic island rising above the global early Archaean ocean. Precipitation produces small hydrothermal pools that undergo cycles of evaporation and refilling (hydrothermal field and geyser shown at center of island).

Mentions: The setting for the proposed model is a volcanic island emerging from a global ocean 4 billion years ago (Figure 1 and Figure 2). The atmosphere lacked free oxygen, and precipitation produced small hydrothermal pools fed by hot springs. Similar sites today include geothermal regions of Kamchatka and northern California [11]. During the dehydration phase of a cycle, solutes and amphiphiles accumulate on mineral surfaces to form highly concentrated films (Figure 3). The amphiphiles and minerals provide environments conducive for concentrating solutes and driving condensation reactions.


Coupled phases and combinatorial selection in fluctuating hydrothermal pools: a scenario to guide experimental approaches to the origin of cellular life.

Damer B, Deamer D - Life (Basel) (2015)

Computer generated conceptual view of a volcanic island rising above the global early Archaean ocean. Precipitation produces small hydrothermal pools that undergo cycles of evaporation and refilling (hydrothermal field and geyser shown at center of island).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390883&req=5

life-05-00872-f001: Computer generated conceptual view of a volcanic island rising above the global early Archaean ocean. Precipitation produces small hydrothermal pools that undergo cycles of evaporation and refilling (hydrothermal field and geyser shown at center of island).
Mentions: The setting for the proposed model is a volcanic island emerging from a global ocean 4 billion years ago (Figure 1 and Figure 2). The atmosphere lacked free oxygen, and precipitation produced small hydrothermal pools fed by hot springs. Similar sites today include geothermal regions of Kamchatka and northern California [11]. During the dehydration phase of a cycle, solutes and amphiphiles accumulate on mineral surfaces to form highly concentrated films (Figure 3). The amphiphiles and minerals provide environments conducive for concentrating solutes and driving condensation reactions.

Bottom Line: Two kinds of selective processes can then occur.The second is a chemical process in which rare combinations of encapsulated polymers form systems capable of capturing energy and nutrients to undergo growth by catalyzed polymerization.Given continued cycling over extended time spans, such combinatorial processes will give rise to molecular systems having the fundamental properties of life.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomolecular Engineering. bdamer@ucsc.edu.

ABSTRACT
Hydrothermal fields on the prebiotic Earth are candidate environments for biogenesis. We propose a model in which molecular systems driven by cycles of hydration and dehydration in such sites undergo chemical evolution in dehydrated films on mineral surfaces followed by encapsulation and combinatorial selection in a hydrated bulk phase. The dehydrated phase can consist of concentrated eutectic mixtures or multilamellar liquid crystalline matrices. Both conditions organize and concentrate potential monomers and thereby promote polymerization reactions that are driven by reduced water activity in the dehydrated phase. In the case of multilamellar lipid matrices, polymers that have been synthesized are captured in lipid vesicles upon rehydration to produce a variety of molecular systems. Each vesicle represents a protocell, an "experiment" in a natural version of combinatorial chemistry. Two kinds of selective processes can then occur. The first is a physical process in which relatively stable molecular systems will be preferentially selected. The second is a chemical process in which rare combinations of encapsulated polymers form systems capable of capturing energy and nutrients to undergo growth by catalyzed polymerization. Given continued cycling over extended time spans, such combinatorial processes will give rise to molecular systems having the fundamental properties of life.

No MeSH data available.


Related in: MedlinePlus