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经济学人下载:被时间遗忘的虫子(1)
Far from the life-sustaining light of the sun, the deep sea floor appears barren and desolate.
远离能够维持生命的阳光,深海海底显得贫瘠荒凉。
Its appearance, however, belies a thriving bacterial ecosystem that may contain as much as 45% of the world's biomass of microbes.
然而,它的表层掩盖了一个繁荣的细菌生态系统,其中可能包含了世界上45%的微生物生物量。
This ecosystem is fuelled by what is known as marine snow—
这种生态系统是由所谓的海雪堆积形成——
a steady shower of small, nutrient-rich particles that fall like manna from the ocean layers near the surface, where photosynthesis takes place.
一阵阵营养含量丰富的小颗粒,像甘露一样从发生光合作用的海面附近的海层中源源不断地飘落下来。
Not all of the snow is digestible, though. And the indigestible parts build up, layer upon layer, burying as they do so the bugs in the layer below.
不过,并不是所有的雪都能融化。无法融化的部分一层一层堆积起来,将虫子埋在了表层之下。
To look at how well these bacteria survive entombment
为了观察这些细菌被埋藏后的生存状况,
a group of researchers led by Morono Yuki of the Japan Agency for Marine-Earth Science and Technology
由日本海洋地球科学技术厅的Morono Yuki
and Steven D'Hondt of the University of Rhode Island studied samples collected in 2010 by the Integrated Ocean Drilling Programme,
以及罗德岛大学的Steven D'Hondt所带领的研究团队研究了2010年综合大洋钻探计划收集的样本,
a decade-long international expedition of which they were part. Their results, just published in Nature Communications, are extraordinary.
该计划是一项长达十年的国际探险的一部分。他们的结果(刚发表于《Nature Communications》)非常了不起。
They seem to have brought back to life bacteria that have been dormant for over 100m years.
他们似乎复活了一种已休眠1亿多年的细菌。
For many microbes, burial is an immediate death sentence. Some, however, are able to enter a state of dormancy—
对很多细菌而言,被埋葬就等于直接被判了死刑。然而,一些细菌能够进入一种休眠状态——
slowing their metabolisms down almost, but not quite, to zero.
将它们的新陈代谢速度降至趋于零。
They can remain in this state for considerable periods. But precisely how long has been a subject of debate.
它们能够在这种状态中维持很长一段时期。但究竟能维持多久一直是有争议的话题。
The samples Dr Morono and Dr D'Hondt chose for examination came from a place in the Pacific Ocean
Morono博士和D'Hondt博士选择检查的样本来自太平洋的某个地方,
where the sea bed is nearly 6,000 metres below the surface. That made drilling a challenge.
那里的海床位于海面下近6000米处。这就给钻探带来了挑战。
But the expedition was able to recover sediment cores stretching all the way down to the underlying rock—a thickness of 100 metres in some cases.
但是这次探险能够恢复一直延伸到地下岩石的沉积物岩心,在某些情况下其厚度达了100米。
The oldest material in these cores dated back 101.5m years, to the middle of the Cretaceous period, the heyday, on land, of the dinosaurs.
这些岩心中最古老的物质能够追溯到1.015亿年前的白垩纪中期,也就是恐龙在陆地上的全盛时期。
Examination of the sediments showed that even the oldest still contained a few bacteria.
对沉积物的检查表明,即便是最古老的物质中也含有一些细菌。
The question was, were these organisms dead or alive? To find out, the researchers incubated the samples,
问题是,这些生物体是死是活?为了查明,研究人员培育了这些样本,
slowly feeding them compounds rich in carbon and nitrogen in order to coax any still-living microbes out of their dormancy.
慢慢地给它们喂食富含碳和氮的化合物,以诱使任何仍活着的微生物脱离休眠状态。