tpo 34 Summaries the points made in the lecture being sure to explain how they case doubt on specific points made in the reading passage

Both the reading and the lecture are about the extinction of Steller's sea cow. The article claim three theories that explain this disappearance. As opposed to, the lecturer refute all these three theories saying that none of those are convincing.

First of all, the writer points out that the sea cows may have been over hunted by native Siberian. Therefore, the population of sea cows quickly diminished. However, the lecturer contradicts this point by reasoning that since the size of this marine animal is huge about nine meters long, the native people did not need to hunt a lot of them. Hunting just a few of sea cows were enough to feed the entire population. As a result, this claim is not convincing.

The second argument the author gives is that extinction happened because of the ecological changes, which lead to the decline of their main food source , kelp. Consequently, kelp responded negatively to these changes. On the contrary, the professor cannot disagree more, explaining that if ecosystem disturbances had happened, other marine animals should have been effected. Currently, there is no report about the negative effect on other marine animals such as wheals. Therefore, no indication of this phenomenon means that there was no shortage on food.

Finally, on one hand the reading states that with the arrival of Europeans fur traders, after 1741 could have been the main cause of sea cows extinction. On the other hand, the lecturer declare that the number of sea cows was already low when Europeans arrived before 1700's. This tells us that there could have been something else that cause extinction of sea cows. The professor elaborates on by saying that they still do not know exactly what that might be, but it is certain that Europeans were the last to arrive. So that explains that they were not the cause of extinction of sea cows.

In conclusion, the points made by reading contrast with the lecturer.