TPO 39 integrated writing

Both the reading and the lecture are discuss the possibilities that cause the mass extinction at the end of the Triassic period. The reading provides three possible reasons, however, the lecturer claims that those are not good explanations of the extinction.

First, the reading suggests that the decline of sea level causing animals which rely on the ocean resources died out. Nevertheless, the lecturer points out that the sea level was declining gradually during Triassic period. The fluctuation of the sea level was slowly declining in million years. That is to say, the whole eco-system can adapt the changes. The phenomenon can't be a significant factor.

Secondly, the reading proposes that SO2 blocks the sunlight, so the cooling climate dies out the organisms. Yet, the lecturer states that the SO2 only effect the climate in a short period. SO2, the product of volcanic activity, can combine with water and turn into rain. As the result, the SO2 can't stay in the atmosphere for a long time to make a huge different of the environment.

Third, the reading asserts that the debris of asteroids strike blocks the sunlight and causes organism disappear. Once again, the speaker holds a different perspective. She said that even though the craters truly exist, the craters are dating back to 12 million years before the extinction. Thus, the craters are nothing to do with the situation.