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  • [Myths and misconceptions about evolution]

    【對於演化論的迷思與誤解】

  • Let's talk about evolution.

    讓我們談談演化。

  • You've probably heard that some people consider it controversial, even though most scientists don't.

    你可能聽說有些人認為它具爭議性,雖然多數科學家不如此認為。

  • But even if you aren't one of those people and you think you have a pretty good understanding of evolution,

    即使你不是反對人士之一且認為自己非常瞭解演化,

  • chances are you still believe somethings about it that aren't entirely right, things like,

    你仍可能相信ㄧ些不完全正確的觀念像是,

  • "Evolution is organisms adapting to their environment."

    「演化是生物個體適應它們的生存環境。」

  • This was an earlier, now discredited, theory of evolution.

    這是一個老舊,現在已被推翻的演化理論。

  • Almost 60 years before Darwin published his book, Jean-Baptiste Lamarck proposed that creatures evolve by developing certain traits over their lifetimes and then passing those on to their offspring.

    在達爾文發表它的巨作的 60 年前,拉馬克提出物種於一生中可能發展各種特徵然後將之傳給後代。

  • For example, he thought that because giraffes spent their lives stretching to reach leaves on higher branches, their children would be born with longer necks.

    例如:他認為由於長頸鹿一生都在伸長脖子吃樹梢的葉子,牠們的後裔將會擁有更長的脖子。

  • But we know now that's not how genetic inheritance works.

    現在我們知道基因遺傳並不是這樣。

  • In fact, individual organisms don't evolve at all.

    事實上,生物個體並不會演化。

  • Instead, random genetic mutations cause some giraffes to be born with longer necks, and that gives them a better chance to survive than the ones who weren't so lucky,

    而是基因突變隨機使得有些長頸鹿生來就有較長的脖子,那使牠們生存的機率提升而其它的就沒那麼幸運,

  • which brings us to "survival of the fittest".

    這觀念帶我們到「適者生存」。

  • This makes it sound like evolution always favors the biggest, strongest, or fastest creatures, which is not really the case.

    這聽起來好像演化總是偏好最大、最強壯,或最快的動物,事實並不如此。

  • For one thing, evolutionary fitness is just a matter of how well-suited they are to their current environment.

    首先,演化適存度只反應生物是否適合現在的環境。

  • If all the tall trees suddenly died out and only short grass was left, all those long-necked giraffes would be at a disadvantage.

    如果所有的樹突然消失只剩下短草,所有的長頸鹿都會處於不利。

  • Secondly, survival is not how evolution occurs, reproduction is.

    其次,演化的延續靠的不是生存,而是生殖。

  • And the world is full of creatures like the male anglerfish, which is so small and ill-suited for survival at birth that it has to quickly find a mate before it dies.

    世界上多的是物種像是雄性的鮟鱇魚,牠們出生時既小又不適生存,必須迅速於死亡前找到配偶。

  • But at least we can say that if an organism dies without reproducing, it's evolutionarily useless, right?

    那這樣我們可以說如果有一個物種沒生殖就死亡,那在演化上就沒用,對吧?

  • Wrong!

    錯!

  • Remember, natural selection happens not at the organism level, but at the genetic level, and the same gene that exists in one organism will also exist in its relatives.

    記住,天擇並不是針對物種個體,而是在基因層面,而存在於一個個體中的基因也會存在於其親屬。

  • So, a gene that makes an animal altruistically sacrifice itself to help the survival and future reproduction of its siblings or cousins,

    所以使生物犧牲自我來幫助後代子孫或親屬的生存或生殖的基因,

  • can become more widespread than one that is solely concerned with self-preservation.

    繁衍的數目可大於只在乎保存自我的基因。

  • Anything that lets more copies of the gene pass on to the next generation will serve its purpose, except evolutionary purpose.

    任何能使更多基因複製並傳給後代的機制都可以達到這個目的,除了演化目的。

  • One of the most difficult things to keep in mind about evolution is that when we say things like,

    演化論其中一個最困難的概念就是當我們說:

  • "Genes want to make more copies of themselves," or even, "natural selection," we're actually using metaphors.

    「基因想要增加自己的數目」,或甚至「天擇」,這些其實都是比喻。

  • A gene doesn't want anything, and there's no outside mechanism that selects which genes are best to preserve.

    基因並不想要作任何事,並沒有一個外來的機制選擇哪些基因是最適合保存。

  • All that happens is that random genetic mutations cause the organisms carrying them to behave or develop in different ways.

    真正發生的是,隨機基因突變會使得生物個體產生不同行為或發展。

  • Some of those ways result in more copies of the mutated gene being passed on, and so forth.

    而其中有些行為最後使某些突變基因被傳到下一代,如此而已。

  • Nor is there any predetermined plan progressing towards an ideal form.

    並沒有一個使物種演化並臻至完美的計畫。

  • It's not ideal for the human eye to have a blind spot where the optic nerve exits the retina, but that's how it developed, starting from a simple photoreceptor cell.

    例如:人視神經與視網膜接觸點會產生不完美的盲點,但是人眼就是這樣,自一個簡單的感光細胞發展出來。

  • In retrospect, it would have been much more advantageous for humans to crave nutrients and vitamins rather than just calories.

    以現代角度思考,人類如果能著重營養和維生素的攝取,而不單是熱量那該有多好。

  • But over the millennia, during which our ancestors evolved, calories were scarce, and there was nothing to anticipate that this would later change so quickly

    但是在我們祖先這幾百萬年來的演化過程之中,熱量是很難取得的,而沒有任何人能預料情況將改變得如此快速。

  • So, evolution proceeds blindly, step by step by step, creating all of the diversity we see in the natural world.

    所以演化是盲目的一步,接著一步,創造我們所見的多樣自然界。

[Myths and misconceptions about evolution]

【對於演化論的迷思與誤解】

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B2 中高級 中文 TED-Ed 演化 基因 個體 後代 物種

【TED-Ed】演化論的迷思與誤解 (Myths and misconceptions about evolution - Alex Gendler)

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    VoiceTube 發佈於 2020 年 10 月 28 日
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