According to National Geographic, the Earth began with a cataclysmic event called the big bang. The BBC states that there have been five major cataclysmic events that caused mass extinctions in the recorded history of the Earth.Know More
About 450 million years ago, the Ordovician-Silurian event caused the death of approximately 85 percent of the life in the Earth's oceans. The BBC states that nearly all life on Earth lived in oceans during this time period. The second cataclysmic event occurred 359 million years ago during the Devonian period. The Devonian mass extinctions are thought to have occurred over the course of millions of years and included several mass extinction events. This event also mostly affected seas and sea life.
According to Wikipedia, the next mass extinction is thought to have killed approximately 96 percent of life on Earth during the Permian mass extinctions, which occurred over the course of millions of years. The Triassic-Jurassic extinctions affected marine life, birds and reptiles, and caused about 50 percent of land and sea animals to become extinct. The dinosaur extinctions occurred during the fifth cataclysmic event on record. During the Cretaceous-Tertiary event, the fifth cataclysm, the Earth was affected by many events that caused extinctions to occur. The final event that prompted mass dinosaur and sea life extinctions was a meteor that hit southern Mexico.Learn more about Prehistory
The earliest fossil evidence found suggests that life has existed on Earth for 3.5 to 3.9 billion years. The surface of the planet was hypothesized to be inhospitable to all life until after the Late Heavy Bombardment, which occurred roughly 3.8 to 4.1 billion years ago.Full Answer >
Human beings are on Earth, as opposed to any of the other planets in the solar system, because it is uniquely able to support the development of life. Some scientists speculate that Earth hosts the only intelligent life in the universe. Others believe there are many other habitable planets.Full Answer >
The Precambrian Supereon was the longest single time period in Earth's history. Beginning 4.6 billion years ago, and lasting for over 4 billion years, the Precambrian era saw the formation of the Earth, origin of life, rise of multicellular organisms and development of an oxygen-rich terrestrial atmosphere. The Supereon ended with a change to the fossil record, caused by the development of hard-shelled organisms of the Phanerozoic era.Full Answer >
Major events during the Jurassic included the further breakup of the supercontinent Pangaea, the development of subtropical conditions and larger dinosaurs. The earliest bird also took flight during the late Jurassic, and early mammals emerged that would later dominate the Earth.Full Answer >