One major event is the mass extinction at the end of the Cretaceous period of the Mesozoic era. This event led to the rise of mammals, and that is why we are alive today. Without the dinosaurs ever going extinct, the dinosaurs might still be here on this planet. The history of the Earth in its later stages would be drastically changed and would not not be the same at all. Most of the mammals on Earth could be killed by dinosaurs. Another important event was when Pangaea formed in the Carboniferous period. If Pangaea never formed, the continents would not be like they are today. It's possible that the continents could have still been formed but they would not be the same. A third important event is the when Archaeopteris, the first successful trees, in the Devonian period came into being. If trees never existed, we would be be alive and the Earth would definitely be different and other organisms would be on Earth. Only organisms who don't need oxygen would survive. If any of these events never happened, the Earth would not be as it is today.
The longest era is the Precambrian, and it took up most of the time in the history of Earth. The Cenozoic era only just started and yet humans have had a large impact on the world. I was surprised when I found out that humans only take up a very short time in the span of everything since the Earth has formed. I thought that humans were on this planet for longer than they actually are. I think that I just didn't realized how long Earth has been in existence. I also did not really know about the Paleozoic era, and that is the era that I researched. Some important things happened in this era, like the diversification of vascular plants and the colonization of land by fungi, plants, and animals.
Humans have had a large impact on the Earth. The good things that we have done have been to help ourselves to survive and reproduce on this planet. However, we have also had a bad impact on Earth. We are using its resources without knowing what it is doing to Earth. Also, some scientists have evidence that shows what we are doing, like using up the oil on Earth and releasing carbon dioxide in the atmosphere, is harming our planet. Some people are listening and are raising awareness, but not enough. A question that I have is, "Will we do anything to slow this mass extinction we are currently in?" Many people don't know about what is happening on the Earth now. There is climate change and ocean acidification and many other events happening. People are smart enough to come up solutions to the problems that we are facing, but enough minds are not on the problems. I do not have any more questions, but I wonder whether we as humans and as organisms on this planet will try to do something to help the planet, not only ourselves.
