Origins of Life Theories Quiz

Origins of Life Theories

• Creationism: Many cultures explain the origin of life through a divine being.
  • Examples: Mayan mythology (Tepeu and Gucumatz), Egyptian mythology (Ra)
• Spontaneous Generation: Life emerged from non-living matter.
  • Examples: Shakespeare’s play (crocodiles from mud and sun heat), Dutch Dr. Johan B. van Helmont (insects from excrement)

Disproving Spontaneous Generation

• Francesco Redi: Proved maggots come from flies through experiments.
• Louis Pasteur: His experiment was the final blow against spontaneous generation.

Alternative Theories: Panspermia

• Panspermia: Life arrived from outer space.
  • Greek: "Pan" - all, "Sperma" - seed
  • August Arrhenius (1908) proposed life arrived from bacteria or spores from space.

Arguments Against Panspermia

• Outer space is not suitable for life.
• Does not explain the origin of life itself

Oparin-Haldane Theory

• Alexander Oparin (Soviet biochemist, 1921) and J.B.S. Haldane (British geneticist, 1920) proposed the same hypothesis independently.
• Their hypothesis: Biomolecules of life could have formed on primitive Earth.
• Primitive Earth was different:
  • Atmosphere lacked free oxygen but had other gases like methane, ammonia, water vapor, and carbon dioxide.
  • Energy from UV radiation and cosmic rays contributed to the formation of complex biomolecules from simpler molecules.

Miller-Urey Experiment (1952)

• Chemists Stanley Miller and Harold Urey simulated primitive Earth conditions in their experiment.
• Their experiment supported the Oparin-Haldane theory, showing that organic molecules could arise from inorganic precursors.

Events After Biomolecule Formation

• Chemical Evolution:
  • Antonio Lazcano Araujo (Mexican biologist, 1952) proposed key events needed for the first life form.
• RNA World Hypothesis:
  • RNA played a key role in the early stages of life.
• Primitive Metabolism:
  • The development of basic metabolic processes.
• First Membranes:
  • The formation of cell-like structures.

LUCA: Last Universal Common Ancestor

• The first life form is the ancestor of all organisms on Earth.
• Its appearance is unknown.

Why Only One Origin of Life?

• Only possible under the conditions of primitive Earth.
• Earth has changed too much since then making life’s re-emergence unlikely.

Test your knowledge on various theories regarding the origins of life, including Creationism, Spontaneous Generation, and Panspermia. Explore key experiments and prominent figures such as Francesco Redi and Louis Pasteur. Delve into the Oparin-Haldane theory and its implications.