TPO29(integrated)

The professor refutes the idea proposed in the passage. She is of the view that none of the arguments which supports the migration hypothesis is convincing.

First of all, the writer supposes that the edmontosaur's diet and the climate condition in North Slope winter support that migration is unavoidable for getting enough food. However, the lecturer argues that edmontosaurs need not to migrate to find food. She explains that in edmontosaurs' times, the temperature of North Slope region is warmer than today. Also, the time of the sunshine in this region is 24 hours per day in summer. Thus, the growing condition of plants was quite favorable, and even in winter, the remains of dead nutritious plants could also provide enough food for edmontosaurs.

Secondly, according to the passage, the evidence of edmontosaurs' skeleton in the same site shows edmontosaurs were living in a herd. For this, the speaker points out that it doesn't necessarily mean the need of migration. She says, the collective life of edmontosaurs was for protecting against predators possibly. And there is a modern evidence: the Roosevelt elks live in a herd, but they don't migrate.

Lastly, another supporting argument mentioned in the reading part is that edmontosaurs have the physical capability of travelling long distances. The listening part, quite the opposite, provides information that juveniles of edmontosaur are not physically capable of moving such long distances to warmer region probably. Also, the herd would not leave juveniles behind.