Warunki na wczesnej Ziemi

How did cells first emerge on planet Earth? Based on experimental observations, scientists think that specific conditions on early Earth led to the formation of cells in several steps. A series of volcanic eruptions occurred on Earth around four billion years ago, contributing ammonia, methane, hydrogen, and other gases to an atmosphere full of water vapor. As the Earth cooled, the water vapor condensed into oceans.

In the 1920s, scientists suggested that UV radiation or lighting could've caused the formation of small organic molecules in these oceans. In 1952, Stanley Miller and Harold Urey tested this idea in the laboratory. The Miller-Urey experiment simulated Earth's early atmosphere and oceans. In the presence of electricity, they observed the formation of amino acids, the building blocks of proteins. Since then, scientists have suggested that these building blocks may have formed near hydrothermal vents in the ocean, near volcanic activity, or as the result of meteorites hitting Earth.

How did the complex molecules form that we know today? Recent studies have shown that nucleotides can spontaneously link together to form nucleic acids. This indicates that the earliest biomole