经济学人下载:被时间遗忘的虫子(2)

The results shocked Dr Morono,
结果让Morono博士感到震惊，

"At first I was sceptical, but we found that up to 99.1% of the microbes in sediment deposited 101.5m years ago were still alive."
“起初，我表示怀疑，但我们发现在1.015亿年前沉积物中，99.1%的微生物仍然存活着。”

And there was quite a variety of them, too. The team found representatives of phyla called Actinobacteria,
并且种类多样。该团队发现的门类有，放线菌、

Bacteroidetes, Firmicutes and Proteobacteria, all of which are familiar to microbiologists.
拟杆菌、厚壁菌门和变形菌，所有这些都是微生物学家所熟悉的。

In one sample (admittedly from a mere 13.5m years ago) they also discovered representatives of the archaea,
在一个样本中（无可否认，它来自1350万年前），他们也发现了古生菌的代表，

a group of organisms that resemble bacteria under a microscope,
这是一组有机体，在显微镜下看起来像细菌，

but have a biochemistry so different that they are regarded as a separate domain of life.
但在生物化学上却截然不同，因此被视为生命体的一个独立领域。

To find such living fossils from as far back as the Cretaceous is extraordinary.
能发现白垩纪的活化石是非同了不起的。

It is not possible to be sure, given the length of time involved, that they have undergone no growth and cell division whatsoever.
鉴于所涉及时间的长短，无法肯定它们是否经历过任何生长和细胞分裂。

But if they have, it will have been minimal given the lack of nutrients in the ooze they were found in.
但如果有，那也只是最低限度的，因为它们所处的软泥中缺乏营养。

Nor is it likely that they migrated there from layers above.
它们也不可能是从上层迁移过去的。

The ooze in question was sealed off by a bacteria-proof layer of chert-like material called porcellanite.
上述软泥被一种类似硅质岩的材料——瓷状岩——的隔菌层所封闭的。

This discovery will therefore throw interesting light on the evolution of bacteria on Earth.
因此，这一发现将为地球上细菌的进化提供有趣的线索。

It will also raise the spirits of those who hope to find life elsewhere in the solar system.
它还将激励那些希望在太阳系其他地方找到生命的人。

The sediments that will be examined for signs of biology by Perseverance,
“毅力”号火星探测器将检测一些沉积物中的生物迹象，

an American Mars rover which was awaiting lift-off from Cape Canaveral, in Florida, as The Economist went to press,
本刊付印时，“毅力”号火星探测器正在佛罗里达卡纳维拉尔角等待发射

are 35 times older than those studied by Dr Morono and Dr D'Hondt,
这些沉积物比Morono博士和D'Hondt博士研究的那些还要古老35倍，

and have not had the protective shielding from environmental degradation
并且没有因埋藏在海底许多米深深的覆盖层下

that comes from being buried at the bottom of the sea under many metres of overburden.
而出现的防止环境恶化的防护屏。

But future Mars rovers will drill beneath the planet's surface into strata that have had equivalent levels of protection from rock above them, if not from seawater.
但未来的火星探测器将深入地球表面，钻探到具有同等保护水平的地层，这些地层即使没有受到海水的保护，也会受到上面岩石的保护。

And a factor of 35, though large, does not sound insurmountable.
35倍差距的因素虽影响较大，但听起来并非不可克服。