TPO 49 Task1

The reading passage presents evidence to support the possibility that humpback whales use stars to navigate when they migrate long distances. The lecturer, however, characterizes these evidence as "unconvincing" and offers alternate explanation for each of the points made by the author.

First, according to the reading passage, the complexity of whales' brains enable them to make use of their cognitive ability and navigate through abstract stimuli such as stars. The professor rebuts this argument when he brings up the fact that there is no connection between overall intelligence and the ability to navigate by the stars. He uses ducks as an example of animals that can innately use stars for finding directions even though their cognitive function is just average.

Second, it is believed by the writer that humpback whales only have stars to rely on if they orient themselves by external objects or forces in the open sea. The speaker adds another external force that whales can possibly use to navigate which is the Earth's magnetic field. In fact, whales are known to be sensitive to magnetic field since they have biomagnet in their system which can act as an internal compass and guide them through the ocean.

Third, while the writer thinks that whales float up once in a while because they want to look at the stars for orientation, the professor correctly notes that there are no stars during the day where whales are observed to keep their heads above the water. Moreover, he mentions other fish in the ocean also sky-hoping for a different purpose. Sharks, for example, float up for some minutes to look for preys rather than looking at the sky. Therefore, the explanation for whales' sky-hoping behavior presented in the reading passage is just pure assumption.