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  3. University of York biologist Peter Mayhew recently found that global warming might actually increase the number of species on th

University of York biologist Peter Mayhew recently found that global warming might actually increase the number of species on th

admin2013-09-26  55
问题     University of York biologist Peter Mayhew recently found that global warming might actually increase the number of species on the planet, contrary to a previous report that higher temperatures meant fewer life forms—a report that was his own.
    In Mayhew’s initial 2008 study, low biodiversity among marine invertebrates(无脊椎动物)appeared to coincide with warmer temperatures on Earth over the last 520 million years. But Mayhew and his colleagues decided to reexamine their hypothesis, this time using data that were " a fairer sample of the history of life. " With this new collection of material, they found a complete reversal of the relationship between species richness and temperature from what their previous paper argued: the number of different groups present in the fossil record was higher, rather than lower, during "greenhouse phases. "
    Their previous findings rested on an assumption that fossil records can be taken to represent biodiversity changes throughout history. This isn’t necessarily the case, because there are certain periods with higher-quality fossil samples, and some that are much more difficult to sample well. Aware of this bias, Mayhew’s team used data that standardized the number of fossils examined throughout history and accounted for other variables like sea level changes that might influence biodiversity in their new study to see if their old results would hold up.
    Two years later, the results did not. But then why doesn’t life increasingly emerge on Earth as our temperatures get warmer? While the switch may prompt some to assert that climate change is not hazardous to living creatures, Mayhew explained that the timescales in his team’s study are huge—over 500 million years—and therefore inappropriate for the shorter periods that we might look at as humans concerned about global warming. Many global warming concerns are focused on the next century, he said—and the lifetime of a species is typically one to 10 million years.
    " I do worry that these findings will be used by the climate skeptic community to say ’ look, climate warming is fine,’ he said. Not to mention the numerous other things we seem to do to create a storm of threats to biodiversity—think of what habitat(栖息地)destruction, overfishing, and pollution can do for a species’ viability(生存力). Those things, Mayhew explained, give the organisms a far greater challenge in coping with climate change than they would have had in the absence of humans.
    " If we were to relax all these pressures on biodiversity and allow the world to recover over millions of years in a warmer climate, then my prediction is it would be an improvement in biodiversity," he said. So it looks like we need to curb our reckless treatment of the planet first, if we want to eventually see a surge in the number of species on the planet as temperatures get warmer. We don’t have 500 million years to wait.  
What is the finding of Peter Mayhew’s recent study?
选项 A、Higher temperature causes the low biodiversity of marine invertebrates.
B、Fossil record can represent a relatively believable history of life.
C、The number of fossils was higher during greenhouse phases.
D、Global warming might promote the richness of species on Earth.
答案D
解析 事实细节题。本题考查彼得·梅休的最新研究成果。定位句指出，他发现气候变暖可能使得地球上物种的数量增加，故答案为D)。A)“气温升高导致海洋无脊椎动物生物多样性降低”，这是梅休2008年最初的研究结论，故排除；B)“化石记录能表现出相对可信的生物发展历史”，第三段第一句已经指出这是他研究前的假设而不是结论，故排除；C)“温室效应阶段化石数量更多”，第二段最后一句指出，是化石中体现的生物物种更多而不是化石本身的数量更多，故排除。
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