▶ Your Answer :
The reading passage explains three possible theories about the reason for Diprotodon's extinction. In contrast, the lecturer casts doubt on the claims of the reading passage and rebuts the theories one by one.
First, the reading passage claims that the low reproductive rate of the Diprotodon cause the disappearance of them. Their ability to reproduce limited at eight so they could not survive under the variable circumstances. But, the lecurer points out that eight offspring is not small. For example, polar bears reproduce only three to five offspring. So the number of offspring of Diprotodon must not be the main reason of the extinction.
Next, the writer suggests that the shortage of food is the reason for the disappearance of Diprotodon. They had to eat a lot of vegetation but early human made it impossible with fire. However, the lecturer asserts that the fire of the early human helpful for them. Fire on earth caused soil to be more nutritious and the vegetation which Diprotodon consumed grow thicker than before. Furthermore, they were able to eat another species of plants.
Last, the reading passage asserts that the predators relate to the extinction of the Diprotodon. Diprotodon were big and slow animals so they were vulnerable from the hunt of the predators. But, the lecturer contends that they were so great size so it was difficult for the predators to eat them. Moreover, Diprotodon and the predators had lived together for more than hundres millions years. The theory is not make sense concerning the abrupt extinction of Diprotodon. |