• UGI USER
  • Jul 17, 2024
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UNRAVELLING ORIGINS: LUCA AND EVOLUTIONARY MYSTERIES

Why in the news?

LUCA’s origins and the molecular clock’s role in evolutionary timelines are making headlines for their insights into life’s beginnings.

source:researchgate

About LUCA and Evolutionary Insights:

Last Universal Common Ancestor (LUCA):

  • LUCA Definition: Last Universal Common Ancestor (LUCA), also known as Last Universal Ancestor (LUA), is the common ancestor of all life on Earth.
  • Hypothesised ancestor of all life forms, including bacteria, archaea, and eukarya.
  • Estimated to have existed around 4.2 billion years ago based on molecular clock analysis.
  • Phylogenetic Basis: LUCA’s existence is inferred from shared genetic ancestry among all organisms.
  • Role in Evolution: It represents the root of the phylogenetic tree, giving rise to diverse categories of life forms on Earth.

Molecular Clock Theory:

  • Developed in the 1960s by Zuckerkandl, Pauling, and Kimura to estimate evolutionary timelines.
  • Calibrated using genetic mutations and fossil records to trace evolutionary events.
Understanding Origins of Life Theories:

Oparin-Haldane Hypothesis (1920s):

  • Proposed the formation of early life from a “primordial soup” through chemical processes.
  • Miller-Urey experiment (1952) demonstrated amino acid formation under simulated early Earth conditions.

Meteorite Theory:

  • Suggested extraterrestrial impacts brought organic compounds to Earth.
  • Supported by discoveries of ancient organic material (2019) and amino acids on asteroids.