TPO 34 A huge marine mammal known as Steller s sea cow once lived in the waters around Bering Island off the coast of Siberia It was described in 1741 by Georg W Steller a naturalist who was among the first European to see one In 1768 the animal be

Both the reading and the lecture talk about some theories with regard to the extinction of sea cow animals in 17th century. The former mentions three hypothesis regarding the main reasons which led to the extinction of these animals. The professor, on the other hand, casts doubt on the idea by saying that we don't know what caused them to be extinct. Accordingly, there are problems for each theories given in the reading section as follows.
First of all, both the author and the lecturer posit whether native Siberian individuals overhunted sea cows or not. The text suggests that because these sea animals were a great food resource for native people, they overhunted them leading their population to be extinct. The man in the lecture, in contrast, rebuts this notion by pointing out that sea cows were massive creatures which were nine meters long weighting 10 tons. According to him, these animals could feed people for months because their population were not so large. Therefore, the first deduction made by the author is flawed.
Second of all, both the writer and the professor put forward whether the ecosystem disturbances resulted in a decrease in the kelp populations which were their main source of food. The writer asserts that ecological alterations helped the decline in the population of the kelps giving rise to sea cows to be extinct. The speaker, however, refutes this idea by explaining that if such severe ecosystem incident happened in the past, it should have affected not only kelps but also other marine creatures such as whales. Accordingly, nevertheless, there is no reports showing a reduction in whales’ populations. Therefore, kelps, which were their critical resource for eating, had no problem and sea cows had not the problem regarding food shortages.
Finally, both the article and the speaker put forth the idea of the European fur traders as a main reasons for these animals' extinction. The reading passage avers that these European traders had special weapons helping them quickly kill a vast majority of the sea cows resulting in their elimination. The lecturer, conversely, rejects this by giving explanation that sea cow population was small when European commercial traders came there and also the reduction in sea cow populations happened long before European individuals arrived to that location. Hence, this is also not a main extinction reasons of that animals.