Can science explain the origin of life?

科學可以解釋生命的起源嗎？

A full scientific explanation for the origin of life does not currently exist,

目前我們對於生命的起源沒有一個完整的科學解釋，

but research groups around the globe are tackling the

但是世界各地的研究員都在嘗試解開這個

mystery.

謎團。

Here we'll take a look at a few of their discoveries.

現在就讓我們來看看他們的發現。

Darwin's theory of biological evolution

達爾文的進化論

tells us that all life on Earth may have originated from a single,

告訴我們或許地球上所有的生命都源自於

relatively simple reproducing creature, living in the distant past.

一個久遠的簡單生物。

This idea is based on many observations one of which is that when living things reproduce

這個理論是根據許多的觀察，其中一個是當生物繁衍時，

children are often born with random new traits. Those with negative new traits are

後代通常都會有隨機的新特徵。擁有不好的新特徵的後代

less likely to survive and reproduce,

較不易生存和繁衍，

those with positive new traits are more likely to survive

而擁有有利的新特徵的後代則比較容易生存

and pass those traits on to their children. Over multiple generations

並將這些特徵傳給下一代。經過好幾代後，

positive traits build up allowing relatively simple life forms to evolve

有利的特徵會不斷的累積，促使相對簡單的生物演變成

into complex life forms

複雜的生物體，

and even split into multiple different species.

甚至可以形成許多不同的物種。

a careful look at the fossil record overwhelmingly confirms Darwin's theory,

化石紀錄的詳細研究驗證了達爾文的理論，

life forms get simpler and simpler as we go back in time.

越久遠的生物越簡單。

The record suggests that all life on Earth emerged from primitive cellular colonies

這些紀錄顯示地球上的所有生命都源自於

which first appeared roughly three and a half billion years ago.

約三十五億年前的原始細胞菌落。

But how did those first reproducing creatures come about?

但是這些原始的生物又是如何出現的呢？

Even the simplest bacteria alive today

即使是現今最簡單的細菌

are far too complex to have popped into existence in a single step.

也都過於複雜，不可能突然出現。

Furthermore, the first reproducing creature could not have developed through

此外，第一個出現的生物不可能是經由

biological evolution,

生物演化而來，

because biological evolution requires reproduction in order to work.

因為生物需要繁衍才可以演化。

The origin of life needs its

生命的起源需要一套

own explanation. The most promising idea right now,

自己的解釋。目前最肯定

the one which is consistently leading scientist to new discoveries,

且持續讓科學家找出新發現的想法

is the idea that life emerged from chemistry!

是生命源自於化學！

Chemistry is the study of matter.

化學是對於物質的研究。

Particularly, how atoms interact and combine to form molecules,

主要是探討原子如何形成分子

and how those molecules interact and combined to form larger systems and structures.

和分子又如何透過交互作用形成更大的系統和結構。

Everything is made of chemicals,

萬物皆是由化學物質所組成的，

the air we breathe, the ground we walk on,

從我們呼吸的空氣、我們行走的大地、

the shoes on our feet, even

我們所穿的鞋子，

the feet inside our shoes.

甚至是鞋子裡面的腳。

That said the chemistry of life is special in two very important ways.

但是生命的化學在兩個層面上非常重要。

First, the chemistry of life is organized

首先，生命所需的化學反應被稱之為

into metabolic pathways. If you look at the cells of any living thing,

代謝途徑。如果你看看生物的任何一個細胞，

even a plant which you wouldn't normally think of as being very lively,

甚至是那些你不會覺得很有生命力的植物，

you discover a world activity! Chemical reactions occur in continuous orderly

你會發現一個充滿活力的世界！這些化學反應都是連續的且遵循一條有條理的

paths,

路徑，

each reaction sparking the next. Scientists call these strange reactions

每個化學反應都會引導下一個反應。科學家把這些奇怪的化學反應稱之為

metabolic pathways.

代謝途徑。

the second oddity of life's chemistry, is that living cells are made of special molecules

生命的化學的第二個奇妙之處是細胞是由特殊的分子所組成的。

building blocks like amino acids and sugars

例如氨基酸和醣類等基本成分。

which we once thought could not be found outside of life. These building blocks

這些成分曾被認為無法在生物體外找到。它們會

combine

結合

to form highly complex and orderly structures like genes,

並形成高度複雜但有規律的結構像是基因、

proteins, and cell membranes.

蛋白質和細胞膜。

In the past, scientist had no idea what powered the strange activities of life,

過去，科學家完全不知道是什麼東西驅動了生命

and produced its unique chemicals. They concluded that life must be fueled by a mysterious energy

並促使獨特化學物質的產生。他們認為生命必定是從一個神秘的來源產生動力。

they called it: The Vital Force!

他們把它稱之為「生命力」！

In 1828 a chemist by the name of Friedrich Wöhler

在 1828 年，一個叫做 Friedrich Wöhler 的科學家

accidentally produced urea in his lab. Urea is one of the main components of urine

意外的在實驗室製造出了尿素。尿素是尿液的主要成分。

One of many chemicals that the scientists of his time thought could only

這是其中一個過去科學家認為

be produced by the Vital Force, acting inside a living creature.

只能由生物身體裡的「生命力」所製造出來的化學物質。

The artificial production and urea suggested

人工尿素的製成表示

that life might not be powered by a mysterious force,

生命也許不是由一個神秘力量所驅動，

but instead is powered by normal chemical reactions,

而是經由普通的化學反應。

which could be studied and understood.

而這些化學反應可以被研究和理解。

Since that time, numerous molecules and cellular activities have been recreated in the lab,

自從那時，科學家在實驗室裡再現了無數的分子和細胞活動

clearly demonstrating a life is powered by normal chemical reactions,

這明確地表示生命是被許多普通的化學反應所驅動，

and suggesting that life may have emerged from non-living chemistry.

並暗示生命也許是源自於無生命的化學反應。

Researchers have recently discovered that many of the building blocks of life,

研究人員近期從外太空墜落的隕星上發現

amino acids and sugars, exist inside of meteorites, rocks which have fallen to the earth from outer space.

許多像是氨基酸和糖類的生命組成成分。

This tells us that these

這也告訴我們這些

special molecules are being produced spontaneously

特殊的分子是

all throughout our solar system and may have been common on the ancient Earth.

會在我們的太陽系中自然的生成，而且或許它們在原始的地球是十分普遍的。

We've also discovered a process now referred to

科學家也發現一個被稱之為

as Chemical Evolution. When simple molecules are left alone with an energy source,

「科學演化」的過程。當簡單的分子與能量來源共存時

they interact with one another often forming larger more complex molecules as time goes on.

它們會相互影響，隨著時間形成更大且更複雜的分子。

Experiments in the lab have shown that chains of chemical

實驗結果也顯示連鎖的化學

reactions can develop,

反應可以在實驗室形成，

some of which resemble the metabolic pathways of life!

而其中一些化學反應類似於新陳代謝的過程！

Surprisingly we've also found that certain molecules have the remarkable ability

我們也意外的發現一些特定的分子有非凡的能力，

to self-assemble into complex orderly structures.

它們可以自己組裝成複雜但有序的結構。

Some self-assemble into hollow spheres

有些可以組裝成空心的球體，

almost identical to the membranes of modern living cells.

幾乎跟現代的細胞模一模一樣。

Others self-assemble into long columns

其他的可以組裝成長型的圓柱體，

remarkably similar to the strains of DNA found in life.

這些和生命中的 DNA 十分相似。

Scientists still have many questions to answer about life's origins:

對於生命的起源，可學家還有很多問題需要回答：

How did different types the molecules first start working together,

不同種類的分子是如何開始合作

eventually producing the genetic code?

並最終形成遺傳密碼？

What were the original reproducing creatures actually like? Were they similar

最初能進行繁殖的生命是什麼樣子的呢？它們跟

to the cells we have today?

現今的細胞很像嗎？

Or were they something much simpler? And finally,

還是它們是更簡單的生物呢？最後，

possibly the most interesting question of all, how likely is it the life

最有趣的問題是，在銀河系裡的其他地方發現

has formed

已經形成或是

or is forming, in other regions of our galaxy?

正在形成的生命的機率有多高呢？

So...

所以

back to the original question, can science explain the origin of life?

回到最初的問題，科學能解釋生命的起源嗎？

Science has not explained the origin of life

科學尚未完整的解釋生命的起源，

in full detail, but researchers are building a theory intended to one day

但研究人員正在建立一套理論，期盼未來能

describe, start to finish,

從頭到尾解釋

how basic chemistry can give rise to living cells!

基礎的化學究竟是如何引發出活生生的細胞！

I'm Jon Perry

我是 Jon Perry

and that's the origin of life, as we understand it so far,

而這是我們目前對於生命起源的了解，

Stated Clearly.

Stated Clearly.