３３〜３５億年前の古代　地球上に生命が活動していた痕跡を確認

Tiny tubes point to ancient life　By Jonathan Amos

Tiny tubes thought to have been etched into South African rocks
by microbes are at least 3.3 billion years old, scientists can confirm.

A new analysis of the material filling the structures shows they were
created not long after the volcanic rock itself was spewed on to the seafloor.

The tubules could therefore represent the earliest "trace" evidence of activity by life on Earth.

The dating work is reported in Earth and Planetary Science Letters.

It is a follow-up study to the University of Bergen team's discovery of the microscopic tunnels and pits first published in 2004.

The structures are seen in rocks from the famous Barberton Greenstone Belt in the Mpumalanga Province of South Africa.

These rocks were originally erupted underwater but over the course of Earth history have been lifted on to dry land.

The basalt that forms the rock had previously been dated to 3.47-3.45 billion years old,
but there was some doubt about when the tubules themselves were created.

By comparing the ratio of different types, or isotopes, of uranium and lead atoms in the material that now fills these tunnels,
the team can show they must have been etched by about 3.34 billion years ago -
in other words, very soon after the host rock itself was formed.

The issue of when life first appeared on our planet is a hotly debated topic.

http://www.bbc.co.uk/news/science-environment-11525674
http://news.bbcimg.co.uk/media/images/49472000/jpg/_49472656_mcloughlin_biotextures_barberton.jpg

ジャップ語でおｋ

>>1
The constant recycling of rock means there are very few locations like
Barberton where a physical record of the ancient Earth can still be examined.

Some researchers argue that the peculiar chemistry of rocks at Isua in Greenland betrays the presence of bacteria some 3.8 billion years ago.

What is different about Barberton is that this geochemical signal is also supported
by shapes and textures - so-called trace fossils - in the rock which could have been cut by the ancient microbes.

It is not the same as having the "body" fossils of the organism, but researchers can make a strong case
that the shapes have a biological origin if they can point to similar tubules made by modern microbes.
The Bergen team believes it can do this.

"We're kind of looking at their 'footprints' - we're looking at the holes, the microborings,
left by the bugs as they dissolved into, or 'chewed', into the rocks," explained Dr Nicola McLoughlin from Bergen's Centre for Geobiology.

"So instead of looking at the microbe itself, you're looking at the cavity or hole that it makes.
We're still working to convince people of the biogenicity of these things and
we think we have really good constraints on the modern seafloor," she told BBC News.

"But things get more difficult in the ancient [setting] because the shapes are simpler
and the chemistry has been modified. What this paper does show, however,
is the progress we have made in dating these structures."

The Barberton rocks in which the tubules were first identified were found at the surface.
The University of Bergen is now analysing rocks that have been drilled from deep underground.

At the very least, this type of investigation will researchers more about what conditions were
like on Earth almost 3.5 billion years ago.

ちょ、それオレちゃん

ﾋﾄみたいな高度な生物って、何億年か前に一度登場してたんでね？

そんなわけないやろぅ

なるほどなー

なるほどなるほど

何度か絶滅してんだろ

>>1
死ね禿

35億とかどこの新参だよ

今の俺たちに繋がる生命ってせいぜい数億年前に誕生したものなんだろ？

日本語に翻訳してからスレたてろや

そういう考え方もあるんだな

わしも年をとりすぎたようじゃ

こ、これは大変だ

ご先祖様か

35億年かけても俺のような人間しか生み出されないというのが生命の限界を物語っている

ああ、知ってる知ってる

旧神か

ムーならよくあること

>>18
６０億も人間いりゃ一つや二つの不良品はできるだろ

↓エキサイト先生

この記事2年位前に見たよ。

漫画スクライド

生命は行き篭りの歴史って事

そんなことは常識だろ。40億年〜38億年あたりが論点。

(ε　ﾟэﾟ)｡.｡o○

最近の子はピクルは実在したとか思ってそうで恐い

>>1
なるほど、理解した

クトゥルー神話か

胸が熱くなるな

いくら英語出来ますアピールしても翻訳文載せねえ奴を俺は認めん

小型チューブは、古代の生活を指すように
アモスではジョナサン

少なくとも3300000000歳の時、科学者が確認することができます小型管は微生物によって
南アフリカの岩にエッチングされていると考えられている。

構造体を充填材の新たな分析は、彼ら自身が海底に噴出した火山岩後間もない作成されて表示されます。

尿細管したがって、地球上の生命の活動の最も早い"トレース"証拠を表すことができます。

デート作業がされ 文学研究報告地球惑星。
こ
れは、ピットの顕微鏡トンネル発見大学ベルゲンチームの研究であるフォローアップ 2004年に初めて公開されて。

構造が有名なの岩石に施されている バーバーグリーンベルト アフリカ州の南ムプマランガインチ

これらの岩石は、もともと水中噴出したが、地球の歴史のコース乾燥した土地に解除されている以上。

岩を形成する玄武岩は、以前は次のが、3.47から3450000000歳に日付を記入されていた尿細管自体が作成されたときのいくつかの疑問があった。

ホスト言い換えれば、非常にすぐ後に - さまざまな種類、または同位体、ウラン、
現在、これらのトンネルを埋める材料の鉛原子の比を比較することで、
チームは彼らが前に3340000000年間でエッチングされていなければ見ることができますそれ自体が形成されたロック。

人生最初に私たちの惑星に登場したときの問題が熱く議論トピックです

>>34
把握した

35億年ぶりだねぇ