Writing -4 Toefl

Large numbers of dinosaur fossils have been discovered in deposits on Alaska’s North Slope, a region that today experiences an extremely cold, arctic climate. One hundred million years ago, when those dinosaurs were alive, the environment of the North S

The reading claims that edmontosours had to migrate in order to survive in winter and provides three reasons of suporting which the professor refutes each of and contradicts the reading.

First, the reading prosits that the build-in urge for food forced edmontosours to migrate to south. However the professor claims that in polar reagon in summer the day's long is about 24 hours and as in past the climate was warmer there this reagon had the capability to grow a lot vegatation. 6 month sunlight provide enourmous amount of food and although this vegatation died in winter, the dead vegatation serve as a food supply for edmontosours during summer. So it contradicts the argument that edmontosours had to migrate.

Second, the reading says that living in herd is a proof for this hypothesis. However, again, professor refutes it by pointing out that there are some species like rosevelt elk which live in herds but don't migarate. Another reason for living in herds is that it provides kind of protection from predators and this extera protection might play integral role to attract edmontosours to live in herds instead of being a proof for migration.

Third, although reading points out that these strange creatures had the capabality to migrate long distances, the juvaniles couldn't migrate like adults. And because adults couldn't leave juvaniles behind they couldn't migrate. juvaniles couldn't survive by their own and they slowed the edmontosours speed.