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#planetary science

2 public questions tagged with this topic.

Chemogeny & biogeny

Major gases of primitive atmosphere included

Volcanic outgassing models and Miller-Urey experimental design suggest primitive atmosphere comprised methane, ammonia, molecular hydrogen and water vapor, without free oxygen. These gases provided carbon, nitrogen and hydrogen for organic synthesis when energized by lightning and ultraviolet radiation. Their reducing character prevented oxidation of intermediates, enabling accumulation of amino acids in oceanic soup. Modern understanding supports CH4, NH3, H2, H2O as dominant components before photosynthetic oxygenation transformed atmosphere to oxidizing state. This concept integrates genetics, ecology and molecular evidence, frequently tested in NEET, GATE and CSIR-NET, highlighting links between genotype, phenotype and environment.

Ref: Alberts et al., Molecular Biology of the Cell, 6th ed., Chapter 1: Origin of Life.

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Chemogeny & biogeny

Primitive Earth atmosphere was considered to be

Geochemical evidence indicates early Earth atmosphere lacked free oxygen and ozone. Instead it contained reducing gases such as methane, ammonia, hydrogen and water vapor from volcanic outgassing. Such reducing conditions prevented oxidative breakdown of newly formed organics, allowing accumulation of amino acids and nucleotides. Laboratory simulations like Miller-Urey replicate this setting. Without oxygen, ultraviolet radiation reached surface driving reactions. Understanding atmospheric chemistry explains why Reducing state is crucial for chemogeny preceding biological evolution. This concept integrates genetics, ecology and molecular evidence, frequently tested in NEET, GATE and CSIR-NET, highlighting links between genotype, phenotype and environment.

Ref: Alberts et al., Molecular Biology of the Cell, 6th ed., Chapter 1: Origin of Life.

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