Microgravity impairs muscle and bone growth,

微重力會減弱肌肉和骨頭的生長

and high doses of radiation cause irreversible mutations.

而高劑量的輻射會造成不可逆的變化

As we seriously consider the human species becoming space-faring,

當我們去認真思考人類的太空旅行

a big question stands.

就會面臨很大的問題

Even if we break free from Earth's orbit

就算我們脫離了地球的軌道

and embark on long-duration journeys among the stars,

搭太空船在星辰中來一趟長途旅行

can we adapt to the extreme environments of space?

我們能適應太空中的極端環境嗎?

This won't be the first time that humans have adapted to harsh environments

這不是第一次人類要去適應嚴酷的環境

and evolved superhuman capabilities.

並且變成擁有超人的能力

Not fantastical powers like laser vision or invisibility,

不是雷射光或是隱形那種幻想出來的超能力

but physiological adaptations for survival in tough conditions.

而是生理上為了在艱困環境下生存的適應力

For example, on the Himalayan mountains

例如，在喜馬拉雅山上

where the highest elevation is nine kilometers above sea level,

最高的高度是海平面往上9公里

an unacclimated lowland human will experience symptoms of hypoxia,

一個在低海拔生活又未馴化的人類就會出現低氧的症狀

commonly known as mountain sickness.

就是我們普遍熟知的高山症

At these altitudes, the body usually produces extra red blood cells,

在這個高度，身體通常會製造出更多的紅血球

thickening the blood and impeding its flow.

使血液變稠，妨礙它的流動

But Himalayans who have lived on these mountains for thousands of years

但千年來住在這些高山上的喜瑪拉雅人

permanently evolved mechanisms to circumvent this process

身體已經擁有應付這個過程的機制了

and maintain normal blood flow.

並且維持正常的血液流動

Cases like that prove that humans can develop permanent lifesaving traits.

這情況證明人類可以發展出求生的特性

But natural adaptation for entire human populations

但對於全部人口的自然適應

could take tens of thousands of years.

可能需要幾萬年的時間

Recent scientific advances may help us accelerate human adaptation

最近科學的進步或許可以幫助我們加快人類的適應能力

to single generations.

對一個單一的世代

To thrive as a species during space travel,

為了在太空旅行中生存成長

we could potentially develop methods

我們可能有潛力發展出一個方式

to quickly program protective abilities into ourselves.

去迅速形成我們的保護機制

A beta version of these methods is gene therapy,

這方法的測試階段就是基因治療

which we can currently use to correct genetic diseases.

我們可以當下用來矯正基因上的疾病

Gene editing technology, which is improving rapidly,

快速進步的基因轉殖技術

allows scientists to directly change the human genome

讓科學家們可以立即改變人類的染色體

to stop undesirable processes or make helpful substances.

阻止不受人歡迎的過程或是製造有用的物質

An example of an unwanted process

舉一個不必要的過程的例子

is what happens when our bodies are exposed to ionizing radiation.

就是當我們的身體暴露在游離輻射(像化療)時發生的事

Without an atmospheric barrier and a magnetic field like Earth's,

沒有大氣層的阻擋和地球的磁場

most planets and moons are bombarded with these dangerous subatomic particles.

大部分的行星和月亮都會被這些危險的次原子粒子轟炸(能量放射)

They can pass through nearly anything

他們幾乎可以穿透任何東西

and would cause potentially cancerous DNA damage to space explorers.

並可能潛在的造成宇宙探險家的DNA發生癌變

But what if we could turn the tables on radiation?

但如果我們在放射物上扭轉了情勢呢?

Human skin produces a pigment called melanin

人類的皮膚製造出黑色素

that protects us from the filtered radiation on Earth.

可以透過過濾地球上的放射物保護我們

Melanin exists in many forms across species,

黑色素存在於很多物種

and some melanin-expressing fungi

有些顯現黑色素的真菌

use the pigment to convert radiation into chemical energy.

還會利用色素將放射物轉化成化學能量

Instead of trying to shield the human body,

與其在人體領域上面嘗試

or rapidly repair damage,

或是快速修補傷害，

we could potentially engineer humans

我們不如潛在地改變人類的基因

to adopt and express these fungal, melanin-based energy- systems.

去採用和呈現像那些真菌一樣，以黑色素為基礎的能量製造系統

They'd then convert radiation into useful energy while protecting our DNA.

然後保護我們的DNA同時，他們會將放射物轉換成有用的能量

This sounds pretty sci-fi,

這聽起很科幻

but may actually be achievable with current technology.

但或許現今的科技是可以達到的

But technology isn't the only obstacle.

科技不是唯一的障礙

There are ongoing debates on the consequences

還有對於結果的後續爭論

and ethics of such radical alterations to our genetic fabric.

以及徹底改變我們基因結構的倫理問題

Besides radiation,

除了放射物以外，

variation in gravitational strength is another challenge for space travelers.

引力力量的變化是宇宙探險家的另一個挑戰

Until we develop artificial gravity in a space ship or on another planet,

直到我們發展出在太空船上及其他行星上的人造重力

we should assume that astronauts will spend time living in microgravity.

我們應該設想一下太空人在微重力下的生活

On Earth, human bone and muscle custodial cells

地球上，人類的骨頭和肌肉細胞

respond to the stress of gravity's incessant tugging

透過所謂重塑和再生的過程更換老細胞

by renewing old cells in processes known as remodeling and regeneration.

來對重力不斷牽引的壓力產生反應

But in a microgravity environment like Mars,

但像在火星上的微重力環境

human bone and muscle cells won't get these cues,

人類的骨頭和肌肉細胞就不會因為重力而發出反應

resulting in osteoporosis and muscle atrophy.

導致骨質酥鬆症和肌肉萎縮症

So, how could we provide an artificial signal for cells

所以，我們要如何提供一個人工的訊息給細胞

to counteract bone and muscle loss?

以彌補骨頭和肌肉的流失呢?

Again, this is speculative,

這是一個推斷

but biochemically engineered microbes inside our bodies

在我們身體中的微生化工程

could churn out bone and muscle remodeling signaling factors.

可能可以製造出發出指令的骨頭和肌肉

Or humans could be genetically engineered

或是人類可能透過基因遺傳

to produce more of these signals in the absence of gravity.

產生出更多在沒有重力情況下的指令

Radiation exposure and microgravity are only two of the many challenges

在險惡的太空環境中，輻射和微重力

we will encounter in the hostile conditions of space.

只是我們將遇到許多挑戰中的其中兩個

But if we're ethically prepared to use them,

但如果我們在倫理道德上準備就緒好好利用

gene editing and microbial engineering are two flexible tools

基因轉植和生化技術就是兩個靈活的工具

that could be adapted to many scenarios.

那可能在許多情況下都能適應了

In the near future, we may decide to further develop

在不久的未來，我們或許會為了太空生活的殘酷現實

and tune these genetic tools for the harsh realities of space living.

決定更進一步的發展這些基因遺傳的工具