跟读练习: Ancient Life as Old as the Universe - 通过YouTube学习英语口语
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Life has existed on one planet for about 4 billion years,
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Life has existed on one planet for about 4 billion years,
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as far as we know.
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But it might have started right after the Big Bang,
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when the universe was much stranger and more fantastic than today.
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A universe that might have allowed life to develop absolutely anywhere.
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The cosmos might be full of the seeds of life,
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sleeping in a dead desert,
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waiting for a few drops of rain to explosively bloom and grow.
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Tiny and not-so-tiny aliens might be everywhere.
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In this video, we're going to put together two highly speculative yet scientifically grounded possibilities.
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Check out the scientific papers in our sources.
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To properly explain it, let's first look at the paradox of life on Earth.
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The Life Paradox For its first few hundred million years,
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Earth was a magma hell, constantly bombarded by asteroids.
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But basically the second things calmed down and the first oceans formed,
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life just appeared and zillions of microbes settled every nook and cranny they found.
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This is kind of strange.
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Life on Earth seems to be almost as old as the planet itself,
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as if it was waiting around for an opportunity.
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But life didn't only appear extremely quickly.
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In that tiny time window,
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it also crossed a huge gap.
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qualify as living things, even microbes need to eat, poop, grow and multiply.
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To do that, they need a genome,
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the biological instruction manual that sets the inner workings of an organism.
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How dead things with no genome become living things with genomes is one of the biggest riddles of science.
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Simplifying a lot, the problem is that to have a functioning genome,
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you need proteins, and to make those proteins,
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you need a functioning genome.
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Both proteins and genomes are super long molecules made of pretty complex blocks that are extremely difficult to assemble by chance.
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It's a chicken-egg paradox with several chickens and eggs.
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Once you have a finished cell,
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the whole system works efficiently.
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But starting from simple dead stuff and reaching
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that level of sophistication by pure chance should require an amazing amount of time for trial and error.
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So how did the first living things manage to cross that gap in just a few hundred million years?
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Most theories about the origin of life try to explain
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that gap by theorizing how some primitive superprebiotic molecules could have efficiently produced the first self-replicating entities.
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But we still don't know how exactly this would have worked.
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Maybe we need to think backwards.
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The Clock of Evolution Think of genomes as a book telling the history of life.
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As time passed and life evolved, more characters were introduced.
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Amoeba, fish, amphibians, dinosaurs, and mammals.
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Over billions of years, the story of life got more and more complex.
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A genome can be viewed as a long string of letters with biological instructions.
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And from microbes to us today,
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functional genomes seem to have been increasing in size at a fairly constant rate.
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The functional genome of fish is more than twice that of worms.
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Our functional genome is about twice bigger than that of fish and so on.
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It is a bit more complicated,
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but for now, let's run with this.
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When we put all these clues together,
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it seems that genomes have been doubling in size on average every 350 million years or so.
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As if evolution had been following an exponential inner clock.
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But it gets even stranger.
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The very first microbes that emerged on Earth,
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even if they look simple,
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already seem to have had pretty long and complex genomes.
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But how could life have achieved that level of complexity in such a short time?
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There may be an interesting way to solve this riddle.
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We just take our exponential clock and extrapolate it back in time to the simplest conceivable life form.
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Something equivalent to a being with a genome containing just a few letters.
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But if we do that,
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we end up 10 billion years in the past,
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more than twice the age of Earth,
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which means if life actually evolved like this,
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it didn't start here, but somewhere out there in space.
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This would explain why life started to thrive so quickly on our young planet.
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If it was already present in space like a seed,
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It just needed water and warm temperatures to wake up and go on evolving.
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And it would also explain the high degree of sophistication of the first life forms on Earth.
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They could have been complex already,
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because they might have been evolving for billions of years somewhere else in the universe.
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But could life really be that old?
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Maybe, yes.
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Actually, life could have started shortly after the universe itself was born.
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A Goldilocks baby universe At its most basic level, life needs two things.
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the right chemical elements to form complex molecules,
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and a liquid medium, like water,
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in which those molecules can move and interact.
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The liquid medium needs to stay warm enough to remain, well, liquid.
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So when we search for life in space,
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we focus on Earth-like planets at just the right distance from their star,
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warm enough to sustain liquid water.
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But there was actually a time when almost all of the universe might have been habitable.
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Right after the Big Bang,
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The universe was extremely hot,
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but as the cosmos expanded it cooled and Between about 10
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and 17 million years after the Big Bang
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when the universe was a thousand times younger than today It was between 100 degrees Celsius
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and 0 degrees Celsius the temperature at which water is liquid
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So for this window of time more than 13.7 billion years ago the whole universe
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absolutely every inch of it had the right temperature to support life.
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Of course, the right temperature alone is not enough for life.
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We also need chemical elements like carbon and oxygen,
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which are forged in the cores of stars.
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But were there stars in super early cosmic times?
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Maybe, yes, in regions of the universe where matter was especially dense.
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Such stars would have been very massive and gone supernova in just 3 million years,
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years, seeding the baby universe with the chemical elements needed to form dust,
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asteroids, planets and the ingredients of life.
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Maybe the first ancestors of life were more exotic and didn't even need water,
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but thrived in substances like ammonia or ethane that can stay liquid at temperatures far below zero degrees Celsius.
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They could have been sustained by the lingering warmth of the Big Bang for tens of millions of years longer,
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well into a time when we know for sure there were stars and all the chemical elements.
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The real magic of this idea is that while the universe today is extremely deadly and hostile,
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back then the conditions for life might have been basically everywhere.
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For a period that may have lasted several dozen million years,
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primordial life might have been able to emerge on any rock,
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even between the stars, sowing the universe with the seeds of what,
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billions of years later, would become bacteria,
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trilobites, dinosaurs, and finally us.
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At some point, the universe cooled down below the right temperature for life to thrive,
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but some of those ancestral life forms may have continued to exist in the internal warmth of the first planets,
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frozen in asteroids or hibernating in cosmic dust,
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tiny seeds roaming the cosmos waiting for new hospitable places to continue evolving.
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If they did, life now might be everywhere in the universe. Will we ever know?
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All this makes for a nice story.
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And while both the habitability of the baby universe and our exponential clock of life are reasonable ideas,
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they're still speculative.
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One more possibility among many others trying to explain our existence today.
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But if life came to Earth from outer space,
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then it should have seeded other places in the solar system too.
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Maybe there are fossils in dry riverbeds on Mars.
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will soon find life in the warm underground oceans of Enceladus or Europa.
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Titan has seas, rivers and lakes of ethane and methane as warm as the universe when it was 90 million years old.
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So finding exotic life on Titan would support the idea that life could have originated in the weird baby universe.
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So far when we look out into the cosmos we don't see anyone like us.
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But maybe that's because life needed 10 billion years
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or more to reach the level of complexity that allows for a technological species.
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Maybe there are millions of worlds filled with microbes,
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oceans full of exotic fish,
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and continents of bizarre animals.
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And maybe even others like us that just recently gained consciousness and are beginning to look at the sky,
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wondering if they're alone.
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Life could be flourishing right now in uncountable forms and in all kinds of cosmic environments.
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And if many of us share a common cosmic origin,
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we would all be part of a great cosmic family.
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The answer may lie in our cosmic backyard.
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Let's go and find out.
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本课内容简介
在这一课中，您将通过观看视频《宇宙一样古老的生命》来练习您的英语口语技能。通过对生命起源的深入挖掘，您不仅能提高听力理解能力，还能积累与生命科学相关的词汇。我们将专注于视频中的重要信息以及如何将它们用英语表达出来，帮助您在雅思口语练习中更加自信。同时，您将学习如何运用看YouTube学英语和shadowspeak的技巧，提升您的口语流利度。
关键词汇与短语
- 生命悖论 (Life Paradox)
- 基因组 (Genome)
- 自我复制 (Self-replicating)
- 进化时钟 (Clock of Evolution)
- 微生物 (Microbes)
- 复杂性 (Complexity)
- 原始超前生物分子 (Primitive Superprebiotic Molecules)
- 功能基因组 (Functional Genome)
练习技巧
在练习该视频的过程中，使用shadowing技巧将极大地帮助您提高口语表达能力。建议您从视频开始时的慢速句子入手，重复模仿发音和语调。在每个主要段落结束后，您可以暂停视频，尝试用自己的话复述刚才的内容。此外，注意观察说话者在表达情感和观点时的语气变化，这些都是您在进行雅思口语练习时需要掌握的技巧。
为了达到最佳效果，您可以将视频的播放速度调至稍慢，以便更好地跟上节奏。切记不要急于求成，多次进行重温与练习，能够有效提升您的语言能力。同时，利用shadow speak网站上的资源，您可以找到与生命科学相关的其他视频，继续扩展您对这方面词汇的掌握。
什么是跟读法？
跟读法 (Shadowing) 是一种有科学依据的语言学习技巧，最初开发用于专业口译员的培训，并由多语言者Alexander Arguelles博士普及。这个方法简单而强大：您在听英语母语原声的同时立即大声重复——就像是一个延迟1-2秒紧跟说话者的影子。与被动听力或语法练习不同，跟读法强迫您的大脑和口腔肌肉同时处理并模仿真实的讲话模式。研究表明它能显着提高发音准确性，语调，节奏，连读，听力理解和口语流利度——使其成为雅思口语备考和真实英语交流最有效的方法之一。