The Proterozoic Eon

[Audio] Welcome everyone. I am delighted to present you today the Proterozoic Eon the eon in Earth's history that preceded the emergence of life as we know it. Let's explore together how plate tectonics oxygen levels organisms and environmental events such as glaciations have shaped our world over the past two and a half billion years. Let's dig in. Let's explore and discover. Are you ready? Here we go!.

[Audio] Proterozoic Eon was the longest geologic eon in Earth's history spanning 2.5 billion years from 2.5 billion years ago to 542 million years ago. During this extended period modern plate tectonics were initiated on Earth and these processes eventually shaped the planet's surface..

[Audio] The Proterozoic Eon is a period of Earth's history spanning from 2.5 billion to 542 million years ago. It is marked by the evolution of multicellular life forms and the formation of the continents. During this eon oxygen levels in the atmosphere was low to none allowing for the evolution of anaerobic organisms. Plate tectonic activity also began to shape the land masses and caused changes in climate and ocean chemistry. During the Paleoproterozoic the continents connected to form Rodinia while Mesoproterozoic and Neoproterozoic saw various supercontinents form and break apart. The emergence of early living organisms occurred during this period..

[Audio] During the Paleoproterozoic Era the formation of stable continents and the emergence of cyanobacteria marked major events. These bacteria which existed around 2.3 billion years ago were the first to use photosynthesis to produce energy and oxygen. This allowed the emergence of other forms of life and shaped Earth's atmosphere..

[Audio] Proterozoic Eon extending from 2.5 billion to 542 million years ago was a significant period in life's evolution on Earth. Oxygen levels started to rise in the atmosphere during this time resulting in a major decrease in microbial populations. This significant rise in oxygen had an immense influence on the expansion of eukaryotic cells including the formation of multicellular algae a key development towards the diversification of animals and plants..

[Audio] Proterozoic Eon is the longest period of Earth's history and it marks the start of complex life. During this era Rodinia a supercontinent was formed followed by the gradual break-up of the continents forming continent Pannotia. Multiple glaciations caused the 'snowball earth' event leading to an increase of carbon dioxide in the atmosphere. This shift resulted in the decline of stromatolites while various microfossils like red and blue algae ciliates dinoflagellates testate and amoeba began to appear. In the evolution of life cnidarians a type of multicellular life started to emerge..

[Audio] The Proterozoic Eon was a period of great transformation for the Earth. Tectonic plates of the Earth's crust underwent extensive movement resulting in North America nearly splitting in half. The rocks around Lake Superior and the mountain ranges formed when tectonic plates collided are evidence of this. This Eon also saw the creation of vast amounts of ice ultimately leading to numerous glacial ice ages..

[Audio] Proterozoic Eon was an important stage in the evolution of life on Earth as it involved an uptick of oxygen production in the atmosphere the result of early lifeforms. This oxygen was integral to the atmosphere as it allowed for the onset of large scale ice ages and new iron deposits. Additionally the augmentation of atmospheric oxygen enabled certain lifeforms to adapt fostering the emergence of complex multicellular life for example algae..

[Audio] Focusing on the Proterozoic Eon an important part of Earth's geologic history there are several national parks and other sites dedicated to preserving examples of rocks and fossils from this age. Examples include the Appalachian National Scenic Trail Boston Harbor Islands National Recreation Area Death Valley National Park Glacier National Park Grand Canyon National Park Mojave National Preserve Pipestone National Monument Tonto National Monument and Yukon-Charley Rivers National Preserve. Visiting these sites provides an understanding of the Earth's history..

undefined. [Audio] Proterozoic Eon was a time of tremendous transformation and progress on Earth. It observed the development of eukaryotic organisms featuring a genuine nucleus and other organelles enclosed in a membrane. While this era Earth cooled as well as its atmosphere experienced a boost in oxygen content. Oceans likewise subjected to considerable modifications forming the initial continental racks as well as seeing the development of intricate multicellular life kinds. This period of modification and also advancement was important and also essential for the development of Earth and the emergence of complicated life kinds as we understand it today..

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[Audio] It has been a pleasure to discuss the Proterozoic Eon with you this week. We have looked at the period between 2.5 billion to 541 million years ago including the Neoproterozoic and Paleoproterozoic Eras. We have explored the plate tectonics of the period along with the history of the earth and the cradle of early life. I hope you have gained a greater appreciation for this fascinating period of time. Thank you again for your attention..