Origin of Life Theories:
Various theories exist about how life began, but none have conclusive proof.
The Oparin-Haldane hypothesis, proposed in the 1920s, suggests that life's building blocks formed from a "primordial soup" on early Earth.
The Miller-Urey experiment in 1952 supported this hypothesis by showing that amino acids could be created from inorganic compounds under simulated early Earth conditions.
Another theory suggests that meteorites could have brought life's building blocks to Earth, supported by discoveries of extraterrestrial organic materials and amino acids on asteroids
LUCA and the Molecular Clock:
Life's diversity today is believed to have evolved from a single cell called the last universal common ancestor (LUCA).
The molecular clock theory helps estimate the timing of evolutionary events by tracking mutation rates in genomes.
Researchers use fossil records and genome sequences to calibrate this clock and understand life's evolution.
Recent Findings on LUCA:
A study estimates that LUCA originated around 4.2 billion years ago, shortly after Earth's formation.
LUCA likely had a small genome and produced metabolites that could have supported other emerging microbes.
This pushes back the estimated origin of life by almost a billion years compared to previous fossil-based estimates.
Its Implications:
Understanding LUCA's origin and evolution helps search for life forms elsewhere in the universe.
Insights into evolution can aid in engineering synthetic organisms for various applications on Earth and potentially moderating ecosystems on other planets.
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