Myths and misconceptions about evolution - Alex Gendler

关于进化论的迷思 - 亚历克斯·亨德勒

翻译人员: Geoff Chen 校对人员: Cissy Yun

Myths and misconceptions about evolution.

对于进化论的迷与误解

Let's talk about evolution.

让我们来谈谈进化吧

You've probably heard

你也许听说

that some people consider it controversial,

某些人认为它颇具争议

even though most scientists don't.

尽管大多数的科学家不这么认为

But even if you aren't one of those people

就算你不是反对者

and you think you have a pretty good understanding of evolution,

并且认为自己相当理解进化的概念

chances are you still believe some things about it

你可能依旧相信着

一些不完全正确的想法

that aren't entirely right,

things like,

比如

"Evolution is organisms adapting to their environment."

“演化意谓着生物适应其环境”

This was an earlier,

这是一个旧想法

now discredited,

现在却成了早已被推翻了的

theory of evolution.

进化理论

Almost 60 years before Darwin published his book,

就在达尔文发表其伟大的著作的 60 年前

Jean-Baptiste Lamarck proposed

让-巴蒂斯特·拉马克拉马克指出了

that creatures evolve by developing

生物在一生中形成的

certain traits over their lifetimes

各种特征

and then passing those on to their offspring.

并且将它们传给后代的现象叫做进化

For example, he thought

就像，他认为

that because giraffes spent their lives

由于长颈鹿终其一生

stretching to reach leaves on higher branches,

都在拉伸自己的颈子吃树梢上的叶子

their children would be born with longer necks.

牠们的后裔便因此有了更长的脖子

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

但现在我们知道 基因遗传并非如此

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

事实上，生物本身不会演化

Instead, random genetic mutations cause

是随机的基因突变

some giraffes to be born with longer necks,

使得有些长颈鹿 生来便有更长的脖颈

and that gives them a better chance to survive

这使它们的生存几率

than the ones who weren't so lucky,

比那些不幸没有长“长脖子”的高了许多

which brings us to

这将我们引领到

"survival of the fittest".

“适者生存”的概念

This makes it sound like evolution always favors

这听起来就好像 进化总是偏好

the biggest,

最硕大

strongest,

最强壮

or fastest creatures,

或速度最快的动物

which is not really the case.

但事实并非如此

For one thing, evolutionary fitness is just a matter

首先，进化的适存度

of how well-suited they are to their current environment.

仅仅反映了生物是否适合当下的环境

If all the tall trees suddenly died out

如果所有的树木瞬间消失

and only short grass was left,

只剩下青草地

all those long-necked giraffes

那么所有的长颈鹿

would be at a disadvantage.

都将处于不利的位置

Secondly, survival is not how evolution occurs,

第二，演化的延续仰赖的不是生存

reproduction is.

而是繁殖

And the world if full of creatures

世上物种何其多

like the male anglerfish,

比如雄性的安康鱼

which is so small and ill-suited for survival at birth

它们刚出生时又小又不适存活

that it has to quickly find a mate before it dies.

必须迅速于死亡前 寻找到配偶

But at least we can say

这样我们便可以说

that if an organism dies without reproducing,

如果有一物种没繁衍就死亡

it's evolutionarily useless, right?

那它在演化上就没什么用了是吧？

Wrong!

大错特错！

Remember, natural selection happens

请记住，自然的选择并不

not at the organism level,

针对某些物种的个体

but at the genetic level,

而是针对基因的层面

and the same gene that exists in one organism

存在于某一个个体的基因

will also exist in its relatives.

也会存在于其亲属身上

So, a gene that makes an animal altruistically sacrifice itself

所以让生物牺牲自我

to help the survival and future reproduction

来帮助后代生存

of its siblings or cousins,

或生殖的基因

can become more widespread

其繁衍的数目可以大过于

than one that is solely concerned with self-preservation.

仅仅在乎保存自我的基因

Anything that lets more copies of the gene

任何能使更多基因复制

pass on to the next generation

并传给后代的机制

will serve its purpose,

都可以达到这个目的

except

除了

evolutionary purpose.

进化的目的

One of the most difficult things to keep in mind about evolution

关于进化论的一个最困难的概念就是

is that when we say things like,

当我们说

"Genes want to make more copies of themselves,"

“基因想要增加自己的数量”

or even,

或甚至

"natural selection,"

“自然的选择”

we're actually using metaphors.

这些其实都只是比喻罢了

A gene doesn't want anything,

基因其实不愿做任何事

and there's no outside mechanism

也并不存在一种外部机制

that selects which genes are best to preserve.

来选择哪些基因最适合保存

All that happens is that random genetic mutations

那真正所发生的是，随机的基因突变

cause the organisms carrying them

会使生物个体

to behave or develop in different ways.

产生不同的行为或发展

Some of those ways result in more copies

而其中，有些行为

of the mutated gene being passed on,

最后使得某些突变的基因被传到下一代

and so forth.

仅此而已

Nor is there any predetermined plan

并不存在一个使物种进化

progressing towards an ideal form.

趋于完美的计划

It's not ideal for the human eye to have a blind spot

比如：人的视觉神经 与视网膜的接触点

where the optic nerve exits the retina,

会产生不完美的盲点

but that's how it developed,

但是人眼就是这样的

starting from a simple photoreceptor cell.

它从一个简单的感光细胞发展而来

In retrospect, it would have been

回顾以往

much more advantageous for humans to crave

人类如果能着重 营养和维生素的摄取

nutrients and vitamins

而不单单只摄取热量的话

rather than just calories.

那该有多好

But over the millenia,

但是我们祖先

during which our ancestors evolved,

在这几百万年来的进化过程中

热量是很难取得的

calories were scarce,

and there was nothing to anticipate

而且没有任何人能预料

情况转变地如此迅速

that this would later change so quickly.

So, evolution proceeds blindly,

所以演化的过程是盲目的

step

它一步

by step

接着

by step,

一步

creating all of the diversity we see in the natural world.

创造出我们至今所见到的 多样化自然界