Scientists Discover 50,000-Year-Old 'Super Life' in Mexico
Scientists have found living organisms trapped in crystals that could be 50,000 years old.
The organisms were found in a hot, but beautiful cave system in Naica, Mexico. These ancient life forms can be seen only with a microscope. They are dormant, with all biological activity suspended inside the solid crystals.
Penelope Boston leads the Astrobiology Institute at NASA, the space agency of the United States. She says the ancient microbes were able to exist by eating minerals such as iron and manganese.
She spoke about the discovery recently at a meeting of the American Association for the Advancement of Science. If the findings are confirmed, they will show how microbes can survive in extreme conditions.
Researchers have been studying the microbes for nine years. But they have not reported their discovery in a scientific publication, and other scientists have yet to confirm the findings.
Penelope Boston plans to do more genetic tests on the microbes, which she revived both in the laboratory and in the Mexican caves.
40 strains of microbes, viruses
Forty different kinds of microbes and some viruses were found in the underground area. The genetic structures of these organisms are 10 percent different from those of their nearest relatives. Boston says that means their closest relative is about as genetically different as humans are from mushrooms growing in the forest.
The caves in Naica are 800 kilometers deep. They were once used for mining lead and zinc. Before the miners began working in the caves, the area was isolated from the surface and the outside world.
Some of the caves are as big as the large religious centers built during Europe's Middle Ages. There are crystals covering the walls. The caves are so hot that scientists must wear special clothing to keep cool. The clothing keeps the crystals safe from human germs or other damage.
Boston said the researchers could only work for about 20 minutes at a time before they had to go to a room that was 38 degrees Celsius to cool down.
No surprise in extreme life
NASA officials would not let Boston share her findings with scientific experts before last week's announcement. So scientists could not say much about the findings. But Norine Noonan, a biologist with the University of South Florida, said she believed them.
"Why are we surprised?" Noonan asked. "As a biologist, I would say life on Earth is extremely tough and extremely versatile."
The microbes are not the oldest life forms on Earth. Several years ago, scientists published studies about microbes that may be 500,000 years old and still alive. Boston says those microbes were trapped in ice and salt, not rock or crystal.
Other experts were asked to estimate the age of the Naica microbes. To do this, they looked at where the microbes were in the crystals and how fast those crystals grow.
Boston is also studying microbes commonly found inside caves in other countries, such as Ukraine and the United States. These microbes eat copper sulfate and appear to be impossible to kill. Boston said they show how difficult life on Earth can be.
I'm Jonathan Evans.
1.extreme conditions 极端环境
Although they coped well with the extreme conditions, they were too small for our needs.
2.no surprise 不奇怪；不足为奇
They took note that she showed no surprise at the news of the murder.
3.cool down 冷却；冷静
He has had time to cool down and look at what happened more objectively
4.at a time 每次；一次
Can I borrow two books at a time?
1.Before the miners began working in the caves, the area was isolated from the surface and the outside world.
be isolated from 与...隔离
Patients will be isolated from other people for between three days and one month after treatment.
Several villages in the north have been isolated from the outside world by heavy snowfalls.
2.Before the miners began working in the caves, the area was isolated from the surface and the outside world.
the outside world 外界
They were almost completely cut off from the outside world.
For many, the post office is the only link with the outside world.
科学家在墨西哥奈卡一处高温而又梦幻的洞穴中发现了这些微生物 。这些古老的生命体只能通过显微镜看到 。处于休眠状态中的微生物的生物活性在水晶内暂时静止 。
潘尼洛普·波士顿（Penelope Boston）是美国宇航局的天体生物研究所的负责人 。她表示，这种古老的微生物通过分解铁和猛等矿物质得以存活 。
近期，她在美国科学促进协会的会议上提及这一发现 。该发现一经证实将解释微生物在极端条件下生存的原理 。
科学家研究这种微生物已长达9年 。但是并未在科学刊物上发表过研究结果，其他科学家也没有证实这些发现 。
科学家在地下水晶洞穴发现了40种不同种类的微生物和病毒 。这些微生物的遗传结构同其近亲的遗传结构有10%的差异 。波士顿表示，这意味着该遗传差异如同人类与森林中的蘑菇之间的差距 。
奈卡的地下洞穴距地表达800千米 。这里曾被用来开采铅和锌 。在矿工开采洞穴之前，这里深埋地下与外部隔绝 。
一些洞穴与欧洲中世纪建造的宗教中心一样庞大，洞穴墙壁被水晶覆盖 。洞穴内温度极高，科学家须穿上特制衣服降温 。这些衣服可保护水晶免受人类细菌等其他侵害 。
在上周的公告之前，美国宇航局官员不允许波士顿与科学专家透露这一研究结果 。因此，科学家对该研究知之甚少 。然而，南佛罗里达大学的生物学家诺琳·诺南（Norine Noonan）对他们表示信任 。
这些微生物并非地球上最古老的生命形式 。几年前，科学家发表的一项微生物研究中称，这种微生物或存活50万年且至今仍然存活 。波士顿表示，只不过那些微生物并非封存在岩石或水晶之中而是冰块和盐块里 。
其他专家则需要估算奈卡洞中这种微生物的年龄 。为此，他们检查了这种微生物在水晶中的位置以及水晶生长的速度 。
波士顿还对乌克兰、美国等国洞穴中常见的微生物有所研究 。这些微生物靠硫酸铜存活，并且难以被扼杀 。波士顿称，这表明地球上的生命有多么不易 。