阅读理解 Corals are approaching a brink. Warming oceans, acidification and a constellation of other man-made stressors mean coral reefs may face extinction within the century. And with around 25 percent of all sea life, dependent on the health of coral reefs, if the corals go down, they're taking a huge swath of marine biodiversity with them.
But in a paper published in the journal Science, a team of scientists made a hopeful discovery: Heat tolerance in corals can be inherited, and at a remarkably high rate of success too; 87 percent of all differences in survival rates among the heat-stressed coral they studied was explained by how heat-tolerant the corals' parents were.
'This implies that heat tolerance could not only evolve, but evolve fast,' explained Mikhail Matz, an associate professor of integrative biology and an author on the paper. In other words, some corals are already capable of genetically adapting to warmer oceans.
If heat-tolerant coral parents can have heat-tolerant coral babies, then interbreeding between more and less heat-tolerant corals has the potential to help genetically rescue the next generation of a colony. Humans, the authors posit, could potentially harness the natural genetic variation among corals to help save them. More resilient coral could be born out of 'something as simple as exchange of coral immigrants across latitudes,' said Line Bay, an evolutionary ecologist and another author on the paper. If humans strategically move heat-tolerant, reproductively active corals to vulnerable reefs, the process of 'genetic rescue' might be jump-started.
'This is occasion for hope and optimism about coral reefs and the marine life that thrive there,' Matz said.
Meanwhile, a multitude of other problems face coral reefs. For example, as the paper notes, corals live a long time; from decades to centuries. With climate change poised to measurably warm and acidified oceans within the next several decades, and pollution causing oxygen depletion and 'dead zones' in some areas, 'it has been argued that in such long-lived organisms acclimatization rather than genetic adaptation will play the leading role in their response to climate change,' the paper reads. In other words, to save reefs, something needs to be done for the coral that already exist.
'Existing genetic variation is by no means a magic bullet that will solve the problem once and for all,' Matz said. 'The good news is that genetic variation will buy us some time; but it will eventually 'run out' when the warming progresses beyond the high levels seen now in natural populations. So if we want to save corals (as well as the rest of biodiversity) we will still need to come up with a solution to curb global warming as a global problem.'

【正确答案】 C

【答案解析】推理判断题。文章第四段指出，耐高温的珊瑚与不怎么耐高温的珊瑚异种交配就有希望从基因上拯救下一代珊瑚群体，但并未指出这是唯一办法，故A选项错误，C选项正确。原文指出，更有适应力的珊瑚得以用“简单得如同珊瑚群跨纬度移植一样”的方式出生，B选项与之不符，故排除。第四段还指出，如果人类能够有规划地把耐热性的且繁殖能力强的珊瑚移动到脆弱的珊瑚礁上，“遗传拯救”的过程也许就开始了。D选项是把不耐高温的珊瑚移到脆弱的珊瑚礁上，与原文意思不符，故排除。