Geologic Timeline Reflection

These are the periods of the Earth that seemed most important to me. During the Permian, there were several marine communities and aquatic creatures largely dominated the earth. However, there was a mass extinction at the end of the era that was the largest ever recorded, which was extremely important because it created a niche in which the dinosaurs could rule. If that extinction had never occurred, we might not be here and the world could still be a largely aquatic-ruled planet.  Another important period was the Cambrian, an explosion of life. It gave birth to many new and different species that helped pave the way to the species that we have todayA lot of fossils and other evidences of life can be found from this time, as it was a major turning point when looking at earths history. This period is the first time major groups of animals started to appear with each other, and you could find life in the sea. Another important period is the Creataceous period. In this period, the dinosaurs were still going strong, and then a mass extinction happened. This extinction led to new life, and from previous vodcasts we larned about life growing when a natural event destroys the landscape. It was definitely the most important event throughout the timeline of our Earth's history due to the fact that without it, the world would still be ruled by dinosaurs, and we wouldn't have dominated the food chain and advanced. 

The scale of earth's history is vastly immense, and it took a long time for it to evolve and become what it is today. I found it interesting how we are basically a spec on a scale for the earths lifetime. The earth was not  inhospitable of a place it was until recent years, and especially when we watched a short clip, how short we humans have inhabited the earth. All of our technological, military, and cultural advances seemed to happen over a long time, but in actuality, we appear as a mere speck on the calendar of the earth. However, on our short time on this earth, we have had a major effect,  namely, global warming and pollution. The earth's temperatures have been steadily rising due to our human interactions and if this continues, and we manage to live as long as say the dinosaurs did, then we could experience an earth that is not safe to live on anymore. I would like to know how exactly when the earth was formed and how our planet is so different from others.  Also, I wonder if there are other planets just like ours that have undergone the same process and evolved into a habitat that is capable of sustaining life.