souvik101990 wrote:
Scientists studying climate change have found that global warming not only increases the temperature of the planet but also leads, on average, to an earlier arrival of the spring season and a later arrival of the autumn season. Though some argue that this effect on the seasons is advantageous because it increases the length of the summer growing season, leaders of the World Wildlife Fund fear that many animal species will not be able to adapt to the altered season lengths and will thus soon face extinction.
Which of the following, if true, provides the best evidence in support of the view held by the leaders of the World Wildlife Fund?
(A) When spring arrives earlier than usual, most species of hibernating mammals are forced to emerge from hibernation earlier than usual and to find alternative food sources to supplement their regular diets.
(B) As the planet's temperature rises, the average global sea surface temperature also rises, endangering several marine organisms that reside near the sea surface and that can only survive within very narrow temperature windows.
(C) Many species of salmon rely on seasonal changes in temperature to signal the start of their annual migrations and will leave their freshwater birthplaces early if spring arrives early; as a result, the populations of several types of freshwater insects consumed by those species of salmon will grow exponentially, infesting thousands of acres of crops on which humans rely.
(D) The young of many species of birds and rodents feed exclusively on caterpillars, whose metamorphosis into butterflies is triggered by seasonal changes in temperature.
(E) As the length of the summer growing season increases, the amount of carbon emissions produced by humans gradually increases, exacerbating the increase in global temperatures that will likely endanger hundreds of animal species.
Verbal Question of The Day: Day 28: Critical Reasoning
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RSSFor All QOTD Questions Click HereGlobal warming has two impacts:
1. Increase in temp
2. Early spring and late autumn so longer summer
(So hotter and longer summer!)
Some say that this effect on the seasons is advantageous (longer growing season) but WWF leaders fear that many animal species will not be able to adapt to the altered season lengths.
We need to evidence to support the view of WWF leaders. Note that the view is on impact of season length, not increased temp. So any option that tells us about the impact of increased temp should be ignored. We need to see how change in season length impacts animals.
(A) When spring arrives earlier than usual, most species of hibernating mammals are forced to emerge from hibernation earlier than usual and to find alternative food sources to supplement their regular diets.
Yes, many mammals may be forced to find alternative food sources but it doesn't mean that those sources will not be available. In fact, with long growing seasons, there may actually be additional sources of food available. Hence, we cannot deduce anything from this option.
(B) As the planet's temperature rises, the average global sea surface temperature also rises, endangering several marine organisms that reside near the sea surface and that can only survive within very narrow temperature windows.
This option talks about the impact of increase in planet's temperature. We are to ignore that.
(C) Many species of salmon rely on seasonal changes in temperature to signal the start of their annual migrations and will leave their freshwater birthplaces early if spring arrives early; as a result, the populations of several types of freshwater insects consumed by those species of salmon will grow exponentially, infesting thousands of acres of crops on which humans rely.
This tells us how human crops will be impacted by seasonal changes. If anything, several insects seem to be flourishing as per this option.
(D) The young of many species of birds and rodents feed exclusively on caterpillars, whose metamorphosis into butterflies is triggered by seasonal changes in temperature.
Here is the correct option - it says that the young of many feed EXCLUSIVELY on caterpillars. If seasonal changes trigger their metamorphosis into butterflies, early spring will mean early metamorphosis (from caterpillars, they will turn into butterflies early) and hence the food source (caterpillars) of the young of many species will dwindle. This could lead to a severe impact on animal population because of seasonal changes.
(E) As the length of the summer growing season increases, the amount of carbon emissions produced by humans gradually increases, exacerbating the increase in global temperatures that will likely endanger hundreds of animal species.
This options tells us that seasonal changes could gradually lead to further increase in global temperatures. This increase in temp could endanger many animal species. This option tells us that animals will not be able to adapt to increase in temp. We need to look for an option that tells us how animals will not be able to adapt to seasonal changes. So we are certainly looking for a more direct impact.
Answer (D)