Unit Review

During this unit of our Earths history in geoscience i learned a lot of things. One thing that really surprised me that I learned was how short a time humans have inhabited this planet. Whenever I thought about it, I thought that humans had been dominating the planet for a very long time because we have evolved so much just in the time that we have been here. I also was very surprised to learn how long the Precambrian era was. About 88 percent of our history is an extremely long time. I never knew that there was such an era or how long it lasted. I was also really surprised to find out how long Earth was here without any life inhabiting it. For a very long time Earth was just a bunch of volcanoes, asteroids were constantly hitting it, and the conditions were definitely not conditions that life as we know it could possibly survive in. There wasn't even an atmosphere because there was no ozone layer or oxygen. Finally, we got stromatolites which oxygenated the air and conditions became more livable, but that was still not for a very long time.