Arctic deer live on islands in Canada's arctic regions. They search for food by moving over ice from island to island during the course of the year. Their habitat is limited to areas warm enough to sustain the plants on which they feed and cold enough, at

In the above argument the author has pointed out the correlation between the artic deer using ice as mean of transport from one island to another and global warming which has caused the ice to melt. Though this could be one of the reasons for the extinction of deer on the Canada's artic region but the argument is weakened by the lack of supporting evidence. The author points out three main issues in the write up. First, the means of transport used by the artic deer, second the issue of global warming and melting of ice caps and the third is the basic assumption formed as a conclusion for the argument that the decrease in deer population is due to global warming. The other evidence that need to be evaluated to make the above argument more sound and logical are explained in the following paragraphs.

The author begins the argument by saying that the deer move over ice from island to island for food, and concludes by saying that due to the global warming the artic deer have become extinct as they cannot travel across the islands for food, but he provides no strong evidence for the said motion. The collection of movement patterns of the artic deer through a few years could help determine any other reason for their extinction or the hinderance in their travel for food. Such data could help strengthen the argument and justifying the conclusion that the deer could not travel across island due to melting of ice by global warming and thus starved and became extinct. It could also be possible that they found a suitable weather in a certain area and thus restricted their habitat to that particular island.

The second argument the author puts forward is that global warming has caused a decrease in the ice caps and thus destroyed the natural habitat of the artic deer. The only reason he states this assumption is because the study of the decrease of deer population coincides with the study of melting ice caps by global warming. Thus there is no logical or strong evidence or data to support the said statement. The author can carry out a statistical search on the regions where the deer were said to reside and the rate of melting of the sea ice in those particular regions to make a strong argument. He could also study the migration pattern of the deer in that region to see if the deer moved from those regions which were affected by global warming . Also the reason why the deer are extinct may not even depend on the change in their migration from one island to the other. In a large group of animals it is sometimes seen that a particular disease can affect the whole herd and thus such kind of study can strengthen the conclusion of the argument.

Thus, the author needs to approach the issue of deer extinction from a different perspective and not just state one reason of global warming for the whole extinction of a species. Such evidences will help to bring logic and just in the argument and will provide strong evidence to support it.