Evolution of Earth
How long did it take for the Earth to form?
The Earth formed over a period of approximately 10 to 20 million years from the accretion of dust and gas in the solar nebula.
What is the Late Heavy Bombardment period?
The Late Heavy Bombardment was a period between 4.1 and 3.8 billion years ago when the Earth and other planets in the inner Solar System were subjected to intense meteor impacts, leaving numerous impact craters.
When did the first life forms appear on Earth?
The earliest evidence of life on Earth comes from fossil records of single-celled microorganisms dating back to around 3.8 billion years ago.
What is the significance of the Phanerozoic Eon?
The Phanerozoic Eon, which began around 541 million years ago, is known as the period of visible life. It witnessed the appearance of complex life forms with hard shells and skeletons, as well as the evolution of vertebrates, plants, and eventually humans.
How did the mass extinction event at the end of the Cretaceous Period impact life on Earth?
The mass extinction event around 66 million years ago led to the extinction of dinosaurs and many other species. This event paved the way for the rise of mammals, which eventually gave rise to the diverse mammalian species we see today, including humans.
Evolution of Earth Class 11 Geography Notes
The Earth is a remarkable planet that has undergone a fascinating journey of formation and evolution over billions of years. From its humble beginnings as a hot, molten sphere to the diverse and life-sustaining world we know today, the Earth has witnessed countless transformations shaped by cosmic events and geological processes.
Evolution of Earth Class 11 Geography Notes