Name: 兩起怪事如何影響人類進化 | Sean B. Carroll Segment (How 2 freak accidents shaped human evolution | Sean B. Carroll Segment)
Uploaded: 2025-08-07T18:37:04.000Z
Duration: 19 min 50 s

轉承詞

The odds that any given planet's going to have complex life, I mean, this is really an opinion because we don't know about life anywhere else in the universe, but most of the scientists that I know, and think about this deeply, think the likelihood of life elsewhere is very high.

我的意思是，這真的是一種觀點，因為我們不知道宇宙中其他地方是否存在生命，但我認識的大多數科學家都認為，其他地方存在生命的可能性非常大。

程度副詞

It may not be the sort of life we're used to, it's not giraffes and redwood trees, but at least things like microbes, yeah, I think there's a very high likelihood that it's out there and abundant in our universe.

它可能不是我們習慣的那種生命，不是長頸鹿和紅杉樹，但至少像微生物這樣的東西，是的，我認為它很有可能就在那裡，而且在我們的宇宙中大量存在。

You know, as thinking creatures, and we'd like to think of ourselves as among the most complex things on earth, but when you think about the history of earth, if you visited this planet for the first 4 billion years of its existence, you wouldn't necessarily be that impressed with its life.

你知道，作為有思想的生物，我們願意把自己想象成地球上最複雜的生物之一，但當你回想地球的歷史時，如果你在地球存在的最初 40 億年裡訪問過這個星球，你不一定會對它的生命留下那麼深刻的印象。

It was largely unicellular for that time period.

在那個時期，它基本上是單細胞的。

Only in the last half billion years has life gotten big and, you know, macroscopic.

只有在過去的 5 億年裡，生命才變得巨大，你知道，宏觀化。

So, if we were to be able to go around the universe and sample life from various places, probably the odds are that most of the time it's going to be microbial.

是以，如果我們能夠環遊宇宙，從不同的地方採集生命樣本，可能大部分時間都會是微生物。

That would be biochemically complex, but not necessarily anatomically or behaviorally complex.

這在生物化學上是複雜的，但不一定在解剖學或行為學上是複雜的。

So, hard to judge the frequency with which we're going to find larger, complex behaving creatures on other planets.

是以，很難判斷我們在其他星球上發現更大、行為更復雜的生物的頻率。

A huge number of things had to go right for our species to exist and for each of us individually to exist, for us to be here.

我們這個物種能夠存在，我們每個人能夠存在，我們能夠來到這裡，都離不開大量正確的事情。

And these are at all sorts of scales, the cosmological scale, the geological scale, and the biological scale.

這些都是在各種尺度上進行的，包括宇宙尺度、地質尺度和生物尺度。

When you think about the long history of life on earth, and you might sort of think, well, it's been this progression.

當你回想地球上生命的悠久歷史時，你可能會想，好吧，它就是這樣發展的。

And so, therefore, almost as though it had a direction, almost had a purpose, and, you know, that some things are predictable.

是以，它幾乎是有方向的，幾乎是有目的的，你知道，有些事情是可以預測的。

When you really unpack the geological history of the planet and the biological history of the planet, it's been a random walk through all sorts of events.

當你真正解讀地球的地質史和生物史時，就會發現它是在各種事件中隨機穿行。

So, you know, the earth is evolving, the physical entity of the earth is evolving, and life has to evolve right along with it.

是以，地球在進化，地球的物質實體在進化，生命也必須隨之進化。

And so, we need to have this sort of, understand this relationship, this coupling between the physical planet that life exists on and what's going on with life itself.

是以，我們需要了解這種關係，瞭解生命存在的物理星球與生命本身之間的聯繫。

Intersect those two, and it's an incredible series of accidents that's given us the world we know today.

這兩件事交織在一起，就產生了一系列不可思議的意外，造就了我們今天的世界。

And this is really a deep philosophical rub for humanity.

這確實是人類深層次的哲學問題。

You know, for millennia, philosophers and theologians have sort of asked the question, you know, does everything happen for a reason, or do some things happen by chance?

千百年來，哲學家和神學家們一直在問這樣一個問題：萬事萬物的發生都是有原因的，還是有些事情的發生是偶然的？

And I would really say it's only about the last 60 years or so that scientists would be saying, oh my goodness, it's a remarkable series of events that were required for us to be here, and that so many things could have happened in a different way that we wouldn't be here at all, both individually, for sure, and certainly as a species.

我真的要說，只有在過去 60 年左右，科學家們才會說：哦，我的天哪，這是我們來到這裡所需要的一系列非凡事件，許多事情本可以以不同的方式發生，我們根本不會來到這裡，無論是作為個體，還是作為一個物種，都是如此。

In the book, I wrote a series of fortunate events.

在書中，我寫了一系列幸運的事件。

I almost decided it's like a new origin story.

我幾乎認定這就像是一個新的起源故事。

I'm going to forget the first almost four and a half billion years of life on Earth and start with the asteroid impact 66 million years ago, because that was such a reset for life on the planet.

我打算忘掉地球生命最初的近 45 億年，從 6600 萬年前的小行星撞擊開始，因為那是地球生命的一次重啟。

That is really the catalyst to the making of the world we know now, and it was the eraser for the world that preceded it.

這的確是我們現在所瞭解的世界的催化劑，也是之前世界的橡皮擦。

So, whatever went on 3.8 billion years ago, and it's murky.

所以，38 億年前發生的一切，都是模糊不清的。

It's really hard for scientists to know what's going on, the biochemical events, where this happened, can't even exclude the possibility that life arrived from somewhere else and that then seeded what happened on Earth.

科學家們真的很難知道發生了什麼，生化事件，在哪裡發生的，甚至不能排除生命從其他地方到來，然後在地球上播種的可能性。

So, the origin of life on Earth is a really murky.

是以，地球上生命的起源真的很模糊。

It's incredibly fascinating, but it's really, really hard to get to.

它無比迷人，但真的很難到達。

Once you have cellular life about the grade of a typical bacterium, that story going forward, we're really comfortable with in terms of the evolution of physiology and how you harvest energy from the sun and all the chemical reactions of life on Earth and all the big geological events.

一旦你擁有了與典型細菌等級相當的細胞生命，那麼在生理進化、如何從太陽獲取能量、地球上生命的所有化學反應以及所有重大地質事件等方面，我們對未來的故事都非常滿意。

But bring it more personally to ourselves, I really marked the beginning of our story at 66 million years ago, because the asteroid impact erased essentially the previous world and opened up the world of mammals from which we evolved.

但就我們自身而言，我真正標誌著我們的故事開始於6600萬年前，因為小行星撞擊基本上抹去了之前的世界，開闢了哺乳動物的世界，我們就是從這個世界進化而來的。

And so, I think understanding those last 66 million years is very rewarding and much more concrete than thinking about 3.8 billion years ago.

是以，我認為了解過去的 6600 萬年是非常有意義的，而且比思考 38 億年前的問題要具體得多。

So, what's really remarkable about the time we exist and actually had a role in our emergence is the ice age.

是以，關於我們存在的時間，真正了不起的是冰河時期，它實際上對我們的出現起了作用。

We're living in a really unusual time with respect to Earth's climate.

就地球氣候而言，我們生活在一個非常不尋常的時代。

For the last two and a half million years, we've been in an ice age where the ice comes and goes.

在過去的兩百五十萬年裡，我們一直處於冰河時期，冰來冰去。

So, it advances across the northern hemisphere and then retreats, advances and retreats.

是以，它在北半球前進，然後後退，前進，後退。

But we didn't drop into that until about two and a half million years ago, and the previous ice age was perhaps 300 million years ago.

但我們是在大約 250 萬年前才進入冰河期的，而上一個冰河期可能是在 3 億年前。

So, from, for example, the asteroid impact 66 million years ago, the Earth was ice-free at the poles.

是以，從 6600 萬年前的小行星撞擊開始，地球兩極就沒有冰了。

Imagine that, you know, forests going pole to pole and no ice at all.

想象一下，你知道，森林從一極延伸到另一極，根本沒有冰。

So, a very warm planet, very verdant planet, but it's gone through a gradual cooling over the last 60 or so million years and dropped into this period of the ice ages just two and a half million years ago.

是以，這是一個非常溫暖、非常蔥鬱的星球，但在過去的6000萬年左右，它經歷了逐漸變冷的過程，並在250萬年前進入了冰河時期。

And so, it's interesting to wonder, well, in this unique period, what implications does that have for humanity and for the other creatures on Earth?

是以，我們不禁要問，在這個獨特的時期，這對人類和地球上的其他生物有什麼影響？

There's been a handful of events where about 75% or more of all species have been erased from the planet in a short period of time.

曾經發生過幾次事件，地球上大約 75% 或更多的物種在短時間內被消滅。

We refer to those as mass extinctions, about five in the last half billion years.

我們把這些現象稱為大滅絕，在過去的 5 億年裡大約發生了 5 次。

At the end of the Permian, about 250 million years ago, massive volcanism poured enormous amounts of noxious gases and climate-altering gases into the atmosphere and wiped out perhaps more than 90% of species.

在大約 2.5 億年前的二疊紀末期，大規模的火山活動將大量有毒氣體和改變氣候的氣體排入大氣層，可能有 90% 以上的物種是以而滅絕。

It was a huge transition in life on Earth.

這是地球生命的一次巨大轉變。

And then 66 million years ago, about a six-mile-wide asteroid traveling about 50,000 miles an hour slammed into the Yucatan Peninsula.

6600萬年前，一顆6英里寬的小行星以每小時5萬英里的速度撞向尤卡坦半島。

And the consequences of that impact, again, led to global change, both climatic change, wildfires, et cetera, that erased more than three-quarters of plant and animal species from the planet.

這種影響的後果再次導致全球變化，包括氣候變化、野火等，使地球上超過四分之三的動植物物種消失。

So, what we know about these mass extinctions is that they're associated with really rapid environmental change, different triggers, but really rapid environmental change.

是以，我們對這些大滅絕的瞭解是，它們與非常迅速的環境變化有關，觸發因素不同，但環境變化非常迅速。

Yet, after each of them, life has rebounded very differently.

然而，每一次之後，生活的反彈都截然不同。

The sorts of the winners and losers are really different after each of these events.

每一次事件之後，勝者和敗者的類型都大不相同。

And the winners that took over after, for example, the asteroid impact were mammals, which were relatively small and insignificant for 100 million years prior to that asteroid impact.

例如，小行星撞擊之後的贏家是哺乳動物，而在小行星撞擊之前的一億年裡，哺乳動物的體型相對較小，微不足道。

There's really two big collisions that are a major reason why we're here today.

其實，有兩大碰撞是我們今天在這裡的主要原因。

And those collisions easily might not have happened.

The first was the asteroid impact 66 million years ago.

第一次是 6600 萬年前的小行星撞擊。

So, imagine this, a rock six miles wide, it's probably been orbiting the solar system for, I don't know, a couple of hundred million years or maybe longer.

所以，想象一下，一塊6英里寬的岩石，它可能已經圍繞太陽系運行了，我不知道，幾億年，或者更久。

It happens to enter the atmosphere 66 million years ago and slam into the Yucatan Peninsula.

它恰好在 6600 萬年前進入大氣層，撞上了尤卡坦半島。

So, first of all, it's the largest impact we know of on the Earth or the Moon in the last half billion years.

是以，首先，這是我們所知的過去 5 億年來對地球或月球的最大撞擊。

One in a half billion year or perhaps longer event.

每 5 億年或更長時間才會發生一次。

Second of all, it could have easily missed the planet.

Or third of all, it could have hit somewhere else on the planet.

第三，它可能擊中了地球上的其他地方。

It turns out that geologists think that where it hit really matters, that those rocks on the Yucatan Peninsula contain the right sort of chemical stew, carbonates and sulfates, that when blasted into the atmosphere, created the situation or contributed to the situation of blocking out the sun and essentially shutting down food production across the planet.

原來，地質學家們認為，它擊中的地方真的很重要，尤卡坦半島上的那些岩石含有適當的化學物質--碳酸鹽和硫酸鹽，當它們被炸入大氣層時，就造成了或促成了遮擋太陽的情況，基本上關閉了整個地球的糧食生產。

So, and asteroid had entered, you know, half an hour earlier or half an hour later and hit, for example, in the Atlantic Ocean or the Pacific Ocean and missed the Yucatan.

是以，如果小行星提前半小時或延後半小時進入，例如撞擊大西洋或太平洋，而錯過了尤卡坦半島。

Everything else alive at that time, or at least most of those groups might still be here.

當時還活著的其他一切，或者至少其中大部分群體可能還在這裡。

Mammals would still be a minor group and we wouldn't be having this conversation.

哺乳動物仍然是一個次要群體，我們也不會有這樣的對話。

So, that's one thing that had to go right.

所以，這是必須要做的一件事。

And, you know, it's a random collision of a big rock with an enormous rock that happened 66 million years ago.

你知道，這是一塊大岩石與一塊巨大岩石的隨機碰撞，發生在6600萬年前。

The second big collision, and I think this is, most people have heard the story of the asteroid, but the second big collision people don't really know about, and that is the collision that set in motion the Ice Age.

第二次大碰撞，我想這是大多數人都聽說過的小行星的故事，但人們並不真正瞭解第二次大碰撞，那就是引發冰河時期的碰撞。

Now, we'll get to the impact of the Ice Age on humanity in a minute, but the impact of this collision was to start a cooling of the planet.

現在，我們馬上就會講到冰河時期對人類的影響，但這次碰撞的影響是使地球開始變冷。

And that collision is of the Indian subcontinent, the tectonic plate of the Indian subcontinent with the Asian plate.

碰撞發生在印度次大陸，即印度次大陸板塊與亞洲板塊之間。

And that happened about 40 million years ago.

And that started building, for example, the Himalaya.

例如，喜馬拉雅山就是從那時開始修建的。

And that rock building, what that does, when rock is exposed on the surface of the planet, that rock actually draws carbon dioxide out of the ocean.

當岩石裸露在地球表面時，岩石就會從海洋中汲取二氧化碳。

And the way that carbon dioxide is drawn down is by reacting with rock and then being sequestered in the ocean.

汲取二氧化碳的方式是與岩石發生反應，然後封存在海洋中。

And that process has, over then millions and millions of years, eventually drawn enough CO2 out of the atmosphere to get CO2 levels low enough to tip us into this Ice Age.

經過數百萬年的發展，這個過程最終從大氣中汲取了足夠的二氧化碳，使二氧化碳含量低到足以讓我們進入冰河時期。

You might say, well, wow, you know, how did that happen?

你可能會說，哇，怎麼會這樣？

How did that collision sort of change the world?

Well, it turns out that little piece, that Indian subcontinent, and we call it the Indian subcontinent because that's where it is now, but that was below the equator, down near Madagascar, about 65 million years ago when the asteroid hit.

事實證明，那一小塊印度次大陸，我們稱之為印度次大陸，是因為它現在就在那裡，但那是在赤道下方，馬拉加西附近，大約6500萬年前，小行星撞擊時的位置。

And it was zipping northward at a much faster pace than the other tectonic plates were moving around.

而且，它向北移動的速度比其他板塊移動的速度快得多。

It was smaller, it was thinner than the other tectonic plates.

它比其他地殼板塊更小、更薄。

And those tectonic plates in general, which are where the continents and the oceans are riding on, those were all generated about 140 million years ago when a supercontinent broke up, sort of like the same way a kitchen plate breaks up when it hits the floor, into these various pieces.

而這些構造板塊，也就是大陸和海洋所在的地方，都是在大約1.4億年前，當一個超級大陸碎裂時產生的，就像廚房的盤子碰到地板時碎裂一樣，變成了這些不同的碎片。

And one of those pieces was that Indian subcontinent, which then sort of raced northward relative to the other plates and slammed in to the Asian continent.

其中一塊就是印度次大陸，然後相對於其他板塊向北急速移動，撞向亞洲大陸。

So those two big collisions, the asteroid and the Indian subcontinent with Asia, have a lot to do with the climate that we live in today and the biosphere that we live in today.

是以，小行星和印度次大陸與亞洲的這兩次大碰撞，與我們今天生活的氣候和生物圈有很大關係。

A biosphere that doesn't have dinosaurs, but is full of mammals from which primates, our ancestors, and eventually our species evolved.

一個沒有恐龍的生物圈，卻充滿了哺乳動物，靈長類動物、我們的祖先，以及最終我們的物種，都是從哺乳動物進化而來的。

And it's pretty easy to imagine how the asteroid didn't necessarily have to happen.

而且很容易想象，小行星的出現並不一定是必然的。

And certainly if that plate had broken up in any possible way, we might still be living in a much warmer world and our species might never have evolved on the continent of Africa.

當然，如果該板塊以任何可能的方式破裂，我們可能仍然生活在一個更溫暖的世界，我們的物種可能永遠不會在非洲大陸上進化。

So these two collisions, one really catastrophic, one a little more subtle, they were profound events for the future in terms of humanity.

是以，這兩次碰撞，一次是真正的災難性碰撞，一次是稍微微妙一點的碰撞，它們對人類的未來都是意義深遠的事件。

Because I can certainly say without the asteroid impact, mammals would still be a minor player on the Earth's scene.

因為我可以肯定地說，如果沒有小行星的撞擊，哺乳動物仍然只是地球上的一個小角色。

And of course, we're mammals and we evolved from primates.

當然，我們是哺乳動物，是從靈長類動物進化而來的。

And I think the evidence for that is twofold, is that for 100 million years, mammals coexisted alongside dinosaurs, but they were ecologically much less significant.

我認為這有兩方面的證據：一億年來，哺乳動物與恐龍共存，但它們在生態學上的重要性要小得多。

And then they really took over once those were removed.

一旦這些東西被移走，它們就真正接管了這裡。

And the second impact, the collision that eventually triggered the Ice Age, this is really important because now you've got to think about our ancestors and actually the hominid story.

第二次撞擊，碰撞最終引發了冰河時期，這一點非常重要，因為現在你必須思考我們的祖先，以及人類的故事。

The hominid story is not really a story about warm and cold, sort of when you think about the Ice Ages, it's really about wet and dry.

類人猿的故事其實並不是一個關於冷暖的故事，就像你想到冰河時代一樣，它其實是一個關於乾溼的故事。

And those wet and dry cycles were pretty frequent, geologically speaking, in places like East Africa.

從地質學角度看，這些乾溼週期在東非等地相當頻繁。

And so that puts a lot of pressure on species to evolve.

是以，這給物種進化帶來了很大的壓力。

These intervals of wet and dry, cold and warm, especially in the northern hemisphere, that's a lot of pushing and pulling going on in the plant life and on the animals that adapt to it, etc.

特別是在北半球，這些潮溼和乾燥、寒冷和溫暖的交替出現，對植物生命和適應這種交替的動物等造成了很大的推力和拉力。