吃隕石的微生物可能會(huì)暗示我們外星人的起源

吃隕石的微生物可能會(huì)暗示我們外星人的起源

There are those who believe that we're born of aliens, and not all of them wear tin foil hats.

有些人相信我們是外星人，但不是所有人都戴著錫箔紙做的帽子。

In fact, it's a topic of serious scientific investigation. The idea is sometimes called the "panspermia hypothesis," which proposes that life on Earth did not originate here, but rather was seeded by meteorites carrying alien microorganisms that arose on some other rock in the far-flung universe.

事實(shí)上，這是一個(gè)嚴(yán)肅的科學(xué)研究課題。這種觀點(diǎn)有時(shí)被稱為“生源說(shuō)”，它認(rèn)為地球上的生命并非起源于此，而是由攜帶著外星微生物的隕石在遙遠(yuǎn)的宇宙中其它巖石上形成的。

A meteorite from the NWA 869 strewn field. (Photo: H. Raab [CC 3.0 license]/Wikimedia Commons)

Of course, without any known evidence of alien microbes from elsewhere, it's a difficult hypothesis to test. But new research recently published in the journal Scientific Reports might offer a boost to this much-debated idea.

當(dāng)然，沒(méi)有任何已知的證據(jù)表明來(lái)自其他地方的外來(lái)微生物，這是一個(gè)很難驗(yàn)證的假設(shè)。但最近發(fā)表在《科學(xué)報(bào)告》雜志上的一項(xiàng)新研究可能會(huì)推動(dòng)這一備受爭(zhēng)議的觀點(diǎn)。

The study authors, led by astrobiologist Tetyana Milojevic from the University of Vienna, looked at a peculiar microbe by the name of Metallosphaera sedula, which is known for its voracious metal-hungry appetite. Because meteorites are filled with lots of the food that these microbes crave, researchers wanted to see how well the bugs adapted to a steady diet of extraterrestrial rock.

這項(xiàng)研究的作者是維也納大學(xué)的天體生物學(xué)家泰提亞娜·米洛耶維奇，他們觀察了一種名為“賽杜拉”的特殊微生物，這種微生物以其對(duì)金屬的巨大胃口而聞名。由于隕石中充滿了這些微生物所渴求的大量食物，研究人員想要看看這些微生物是如何適應(yīng)地外巖石的穩(wěn)定飲食的。

What they found was quite remarkable. Not only did the M. sedula heartedly chomp on the meteorites, but they actually harvested food from the space debris more efficiently than they could from Earth stones.

他們的發(fā)現(xiàn)相當(dāng)驚人。它們不僅一心一意地啃食隕石，而且實(shí)際上它們從太空碎片中獲取食物的效率比從地球上的石頭中還要高。

"M. sedula was capable of autotrophic growth on stony meteorite NWA 1172, utilizing metals trapped within it as the sole energy source," wrote the authors. "When grown in the presence of NWA 1172, cells of M. sedula were characterized by intensive vivid motility."

“M. sedula能夠在NWA 1172石質(zhì)隕石上自養(yǎng)生長(zhǎng)，利用其中的金屬作為唯一的能量來(lái)源，”作者寫道。當(dāng)在NWA 1172存在下生長(zhǎng)時(shí)，賽杜拉m.s edula細(xì)胞具有強(qiáng)烈的生動(dòng)的運(yùn)動(dòng)性。

The meteorites clearly produced healthier, fitter microorganisms. Scientists guessed that this might have to do with the diverse content of tasty minerals found on the space rocks. Some of the meteorite material contained around 30 different types of metals, which gave M. sedula a very balanced diet.

隕石顯然產(chǎn)生了更健康、更適宜的微生物。科學(xué)家猜測(cè)，這可能與在太空巖石中發(fā)現(xiàn)的各種美味礦物質(zhì)有關(guān)。一些隕石材料含有大約30種不同類型的金屬，這給了塞杜拉m.s edula一個(gè)非常平衡的飲食。

While this research is hardly proof of panspermia, it does offer a model for how the idea could have worked. Imagine hardy M. sedula-like organisms thriving on some metal-rich alien world in a galaxy far, far away. Then, suddenly, a catastrophe: a collision with another planet. Such a collision could have sent the organisms flying through space, clinging to debris from the world-shattering event.

雖然這項(xiàng)研究很難證明生源說(shuō)，但它確實(shí)為這個(gè)想法如何運(yùn)作提供了一個(gè)模型。想象一下，在一個(gè)遙遠(yuǎn)的星系里，在某個(gè)富含金屬的外星世界里，生命力頑強(qiáng)的瀨戶龍類生物正在茁壯成長(zhǎng)。然后，突然，一場(chǎng)災(zāi)難:與另一顆行星的碰撞。這樣的碰撞可能會(huì)讓這些生物飛向太空，緊緊抓住這次世界大地震的殘骸不放。

But this was an intergalactic voyage that they could survive, because they had all the food they needed for the journey: the meteor that would become their transport.

但這是一次他們能夠幸存下來(lái)的星際旅行，因?yàn)樗麄冇新猛局行枰乃惺澄?成為他們運(yùn)輸工具的流星。

Imagine next that this microbe-carrying meteor found itself on a collision course with a newly-formed planet Earth. Maybe these were the kinds of organisms that first landed on our barren world, eventually evolving into life as we know it today. At the very least, this new research on M. sedula paints a pretty picture as to how this story could have been possible.

接下來(lái)想象一下，這顆攜帶微生物的流星發(fā)現(xiàn)自己正處于與新形成的行星地球的碰撞過(guò)程中。也許這些就是最初出現(xiàn)在我們貧瘠世界的生物，最終進(jìn)化成我們今天所知道的生命。至少，這項(xiàng)對(duì)塞杜拉先生的新研究為這個(gè)故事的發(fā)生描繪了一幅美麗的圖畫(huà)。

It's weird to think that an organism like M. sedula could have been our primordial Adam-and-Eve. Though if you ever find yourself with an odd, unexplained craving for a metal snack, perhaps you'll know why.

想到像塞杜拉先生這樣的生物可能是我們的亞當(dāng)和夏娃的祖先，真是不可思議。如果你發(fā)現(xiàn)自己有一種奇怪的，無(wú)法解釋的對(duì)金屬零食的渴望，也許你會(huì)知道為什么。