The scientific investigation of Earth has led to the formation of theories that explain how the planet as it is now changed over time. The archeological evidence, fossils, the placement of volcanoes, and glaciers serve as evidential proofs that provided the basis for the Plate Tectonics Theory. Importantly, the form of the continents and the coastlines indicate that they coincided with each other and were once a unity. The theory is based on the concept of isostasy that allows the tectonic plates to float on a layer placed beneath them and the concept of continental drift. This idea claims that in the late Paleozoic era, a supercontinent named Pangea existed and was later separated into several pieces (modern continents) due to continental drift.
specifically for you
for only $16.05 $11/page
The Precambrian period in the history of Earth was a long period that started with the planet’s creation and lasted until the first organisms appeared. At the beginning of this era, the planet had a very humid and hot climate, and the atmosphere did not contain any oxygen. With time, the activity of bacteria started producing oxygen; its level grew, thus changing the gas composition of the air. Due to the presence of oxygen in a considerable volume, the planet’s climate became cooler, the humidity in the atmosphere started condensing, and with time oceans appeared on Earth. Thus, the atmospheric changes during the Precambrian period were pivotal for the development of organisms.
The Paleozoic era was a long period in the geological development of Earth that witnessed the appearance and existence of multiple kinds of animals that have become extinct. For example, during the Paleozoic period that started 542 million years ago, arthropods started evolving into the forms of life that are now known as insects. Diverse forms of sea life evolved, including such arthropods as a trilobite. However, at the later stages of the Paleozoic, more developed land-living animals appeared. Some of them include tetrapods that constituted a large group of animals, some of which lived in the sea, and others inhabited land. The latter became the ancestors of dinosaurs and birds in the later stages of Earth’s history.