While working on a timeline to represent the full history of earth, we were asked to reflect about our learning, and provide 3 significant events that impacted Earth's history. I found that the mass extinction during the Triassic period, also known as the End-Triassic extinction was one of the most impactful events in Earth's history. In this one mass extinction, approximately, 252 million years ago, nearly 76 percent of all marine and terrestrial species on the face of the earth were wiped out, along with over 20 percent of all taxonomic families. This event was impactful to Earth’s history primarily because it changed the dynamic of the earth. Although not all, most of the dinosaurs were wiped out, and this allowed mammals to radiate. The cause of this mass extinction is very debated by scientists, but many believe that climate change was the root cause, as some of the species were not able to adapt to the rapidly changing climate.
The second event that is really significant in Earth’s history is the Cambrian Explosion, which was when fossil records of complex animals suddenly appeared. This is considered by many as the most important evolutionary event in Earth's history as it accounted for most of the diversification of life over Earth’s history. It happened nearly 540 million years ago, and it is extremely important to Earth’s history because the diversification of life is necessary for life on Earth.
The last event that is extremely important to Earth's history was the development of cyanobacteria, as it enabled the oxygen levels on earth to rise, allowing for more complex species to live on earth. Many of the current species today rely on oxygen to produce energy and survive, and without the development of cyanobacteria most of the species that currently live on earth would not have been able to live.
Earth’s history spans approximately 4.6 billion years, and what really surprised me is how short, comparatively, humans have lived on earth. On our timeline, every million years was 2 millimeters, and humans were only on earth for barely 1 millimeter. Additionally, there were not many events earlier in earth’s whereas there are many major events happening fairly recently. This would make sense, and goes to show that evolution of earth is picking up as years go by.
Despite being on earth for such a small amount of time compared to Earth's full history, humans have managed to make a powerful impact. In our time on this planet, we have managed to take over it entirely, living on almost every part of it. Further, we have increased climate change, and constantly worsened the overall environment.
I still wonder about what happened during the early years after Earth’s formation. If nothing really happened, I wonder why the major events in Earth's history started happening so late.
Post a Comment