Ad
related to: history of the ecosystem on earth timeline
Search results
Results From The WOW.Com Content Network
The history of Earth is divided into four great eons, starting 4,540 mya with the formation of the planet. Each eon saw the most significant changes in Earth's composition, climate and life. Each eon is subsequently divided into eras, which in turn are divided into periods, which are further divided into epochs. Eon.
Post-Earth Day, besides questions of advocacy and professionalism, ecology also had to deal with questions having to do with its basic principles. Many of the theoretical principles and methods of both ecosystem science and evolutionary ecology began to show little value in environmental analysis and assessment. [124]
The geological history of the Earth follows the major geological events in Earth's past based on the geological time scale, a system of chronological measurement based on the study of the planet's rock layers (stratigraphy). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left ...
Geologic time is the timescale used to calculate dates in the planet's geologic history from its origin (currently estimated to have been some 4,600 million years ago) to the present day. Radiometric dating measures the steady decay of radioactive elements in an object to determine its age. It is used to calculate dates for the older part of ...
Pre-Holocene (1.5 Ma) The time from roughly 15,000 to 5,000 BCE was a time of transition, and swift and extensive environmental change, as the planet was moving from an Ice age, towards an interstadial (warm period). Sea levels rose dramatically (and are continuing to do so), land that was depressed by glaciers began lifting up again, forests ...
Environmental history. The city of Machu Picchu was constructed c. 1450 AD, at the height of the Inca Empire. It has commanding views down two valleys and a nearly impassable mountain at its back. There is an ample supply of spring water and enough land for a plentiful food supply. The hillsides leading to it have been terraced to provide ...
Ordovician Period. The Ordovician spans from 485 million to 444 million years ago. The Ordovician was a time in Earth's history in which many groups still prevalent today evolved or diversified, such as primitive nautiloids, vertebrates (then only jawless fish) and corals. This process is known as the Great Ordovician Biodiversification Event ...
1991. The Mesozoic Era[3] is the era of Earth's geological history, lasting from about 252 to 66 million years ago, comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of gymnosperms and of archosaurian reptiles, such as the dinosaurs; a hot greenhouse climate; and the tectonic break-up of Pangaea.