History of Earth - in brief

History of Earth - in brief - Paleozoo. How old is the Earth? When did life first appear upon it? How did we come to be here? Questions as old as humankind. History of Earth - in brief - an outline of the evolution of the planet from its Hadean origins to its Anthropocene present. A timeline of the history of life on Earth. The Earth has undergone constant change in its billion year history, with life evolving in response to those changes - in particular to the changing atmospheric compositions of carbon dioxide and oxygen. Species extinctions have been a natural part of the evolutionary processes of the planet throughout its long history, however there are now thought to have been at least 8 mass extinction events in the history of the Earth - each of major consequence to life on the planet and of import to our modern understandings of climate change. There have been many extinction events, both great and small, but the most profound of these would be the End-Permian Extinction that closed the Palaeozoic era (~252 Ma). Also known as the Great Dying, it is thought that over 90% of all marine species and 70% of all terrestrial species became extinct. A rapid increase in surface temperatures towards the end of this period brought about a collapse in the carbon cycle - starving life on land and subsequently suffocating life in the oceans. No environmental niche was left unchanged by the Permian Extinction. From the earliest ages of the planet - when microbial blooms spread around the globe - up to the radiation of Homo sapiens, life has repeatedly colonized every viable location on the planet. Life is nothing if not resilient and great extinctions serve to highlight this. Even if only a few isolated pockets of single-celled organisms survived a global extinction event - an event even more destructive than the Great Permian Extinction - life would continue on, evolving, adapting and radiating back across the world as soon as conditions allow. ~ Written and animated by Bruce Currie More information can be found at KEY REFERENCE: Ward and Kirschvink, 2015 ‘A New History of Life’ New-History-Life-Discoveries-Evolution/dp/1408835525 International Commission on Stratigraphy. NASA - Visible Earth catalogue British Geological Society. Geological Society of America Gplates - Earthbytes Paleomap Project - Christopher Scotese. Algol - History of the Earth Other Paleozoo videos include: