Lecture on Earth's History and Evolution

Introduction

• Earth is 4.5 billion years old.
• Conceptualized as a musical train ride through Earth's history in an hour.

Early Earth

• 4.5 Billion Years Ago:
  • Earth formed, initially a hell of lava.
  • Collision with Mars-sized object, Theia, forms the moon.
  • Atmosphere mostly CO2.
  • Hadean Eon: Earth's first eon.

Formation of Water and Life

• Zircons: Evidence of early water presence.
• Heavy asteroid bombardment in the young solar system.
• Sun 30% less bright, greenhouse gases keep Earth hot.
• First Cells: Life begins to form.
• Continuous cooling and formation of oceans.

Paleoarchean to Mesoarchean

• Paleoarchean:
  • First supercontinents forming.
  • Shorter days due to faster Earth rotation.
  • Stromatolites as evidence of early life.
  • Beginning of photosynthesis.
• Mesoarchean:
  • Era of continents, formation of tectonic plates.
  • Hot oceans, expansion of microbes, absence of plants.

Neoarchean and Beyond

• Neoarchean:
  • Proper plate tectonics, more chemical mixing for life.
  • Colonization by prokaryotes.
• Siderian:
  • Great Oxidation Event, oxygen in the atmosphere.
  • Cooling and ice ages begin.

Rhyacian to Orosirian

• Rhyacian:
  • Volcanic activity, Earth unfreezing.
  • Evolution continues despite toxic elements in oceans.
• Orosirian:
  • Largest verified asteroid impact.
  • Formation of great mountain ranges.

Statherian to Calimmian

• Statherian:
  • Formation of supercontinent Columbia.
  • Natural nuclear reactor from uranium deposits.
• Calimmian:
  • Emergence of first eukaryotic cells.
• Formation of Earth's inner core.

Stenian to Tonian

• Stenian:
  • Possible invention of sexual reproduction by algae.
• Tonian:
  • Unicellular predators emerge.
  • Eukaryotes diversify, invent tiny armor.

Cryogenian to Cambrian

• Cryogenian:
  • Earth freezes over.
• Cambrian Explosion:
  • Burst of life variety, major animal groups emerge.
  • Mass extinction follows.

Carboniferous to Permian

• Carboniferous:
  • Peak of forests and marshlands, formation of coal.
• Permian:
  • Formation of supercontinent Pangea.
  • Largest mass extinction in history.

Triassic to Present

• Triassic:
  • Age of Reptiles, dinosaurs dominate.
  • Asteroid impact leads to dinosaur extinction.
• Paleogene:
  • Mammals take over, leads to human history.

Conclusion

• Earth's history is vast and ancient.
• Human existence is relatively new.
• Support for educational projects and further exploration of Earth's history.