IMAT 2015 Q10 [Assumption | Migrating Animals]

Climate scientists in Greenland studying patterns of plant growth have suggested that the early arrival of spring in the Arctic threatens to drive down populations of migrating animals such as caribou. However, comparable studies elsewhere show that their fears are unfounded. A recent study of great tits in Oxfordshire showed the birds are capable of adapting to climate change better than many scientists expected. Over the past half century, the birds have brought forward the date they lay their eggs by two weeks, so that young are born when plant­-eating grubs are most plentiful.

Which one of the following is an underlying assumption of the above argument?

A. Migrating animals in the Arctic can adapt to climate change as successfully as great tits in Oxfordshire.

B. Birds are more adaptable than large mammals such as caribou.

C. Unless animals like the caribou produce their young earlier in the year, their population will fall.

D. The scientists working in Oxfordshire have greater expertise than those working in Greenland.

E. Climate change in Greenland and climate change in Oxfordshire are of the same scale.

Steps

  • identify the question type. Although not phrased in the typical Cambridge format (“What is the assumption in the argument…”) we can easily identify that it is asking for an assumption.
  • Strategy Tool Kit for solving assumptions
  • Find the conclusions
  • Find the reasons
  • Find the unwritten link that the conclusion relies on
  • Discard and decide (use negation test if needed)

Reading this question over, you should immediately notice the transition from what the studies have said about the migration of animals in general, versus the switch into the studies on the great tits, which are only one species of bird. This should be a huge red flag and we will explain down below (see A):

A Migrating animals in the Arctic can adapt to climate change as successfully as great tits in Oxfordshire.

As we mentioned above, there is a distinction between the two different sets of data the author is comparing. The first sets of studies were done on migration animals in general, while the second study focused on one species only; great tits. The author is assuming that all migrating animals will show similar adaptation to climate change as the great tits have. Without this assumption, that the other animals will adapt as well as the great tits have, the argument is useless because the evidence we have is not enough to prove the conclusion of the author - that the populations will not be as affected by climate change as first thought. Therefore A is the correct answer.

B Birds are more adaptable than large mammals such as caribou.

This is an irrelevant detail added to distract us. We cannot assume this, and even so, it weakens the argument because the author is assuming that the birds and large mammals are adapting similarly. Therefore B is incorrect.

C Unless animals like the caribou produce their young earlier in the year, their population will Fall.

The example of the birds bringing forward the date they lay their eggs is an example of adaptation, it does not mean that other animals will do the same. The point of this is to show that it is possible for animals to adapt, and different animals may do different things to adapt. Caribou may have other strategies to adapt, it does not necessarily need to be having their young earlier in the year. Therefore C is incorrect.

D The scientists working in Oxfordshire have greater expertise than those working in Greenland.

The location of the scientist does not correlate with their expertise and we cannot assume this. The first study is on the plants in the artic, while the second study is on the adaption of the animals. They are on two different things. The assumption made by the first study, that the migrating animal populations could decline, is based on the fact that there is a change in plant growth, not on the animal behaviours themselves. The second study however is focused on the animal reaction to climate change, so it is more focused on the animals themselves and not making conclusions based on shifts in the environment. Therefore D is incorrect because the studies are showing different data and therefore ended up with different results.

E Climate change in Greenland and climate change in Oxfordshire are of the same scale.

This is something that is not critical to the argument. This option is talking about things on a gradient, but we only need to know if there is or isn’t climate change in these areas. Climate change is supposed to be a universal effect. This answer is incorrect because, although we can make this assumption, the more important assumption is assuming that the great tits’ behaviour in one area will translate onto other animals in another area (it is like two assumptions in one).